6 files changed, 2286 insertions, 2196 deletions

diff --git a/updater/Android.mk b/updater/Android.mk
index bc763a0ea..4ebb5483a 100644
--- a/updater/Android.mk
+++ b/updater/Android.mk
@@ -1,11 +1,23 @@
 # Copyright 2009 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 LOCAL_PATH := $(call my-dir)
 
 updater_src_files := \
-	install.c \
-	blockimg.c \
-	updater.c
+	install.cpp \
+	blockimg.cpp \
+	updater.cpp
 
 #
 # Build a statically-linked binary to include in OTA packages
@@ -17,8 +29,12 @@ include $(CLEAR_VARS)
 # needed only for OTA packages.)
 LOCAL_MODULE_TAGS := eng
 
+LOCAL_CLANG := true
+
 LOCAL_SRC_FILES := $(updater_src_files)
 
+LOCAL_STATIC_LIBRARIES += libfec libfec_rs libext4_utils_static libsquashfs_utils libcrypto_static
+
 ifeq ($(TARGET_USERIMAGES_USE_EXT4), true)
 LOCAL_CFLAGS += -DUSE_EXT4
 LOCAL_CFLAGS += -Wno-unused-parameter
@@ -44,10 +60,12 @@ endif
 endif
 
 LOCAL_STATIC_LIBRARIES += $(TARGET_RECOVERY_UPDATER_LIBS) $(TARGET_RECOVERY_UPDATER_EXTRA_LIBS)
-LOCAL_STATIC_LIBRARIES += libapplypatch libedify libmtdutils libminzip libz
+LOCAL_STATIC_LIBRARIES += libapplypatch libbase libotafault libedify libmtdutils libminzip libz
 LOCAL_STATIC_LIBRARIES += libflashutils libmmcutils libbmlutils
 LOCAL_STATIC_LIBRARIES += libmincrypttwrp libbz
-LOCAL_STATIC_LIBRARIES += libcutils liblog libstdc++ libc
+LOCAL_STATIC_LIBRARIES += libcutils liblog libc
+LOCAL_STATIC_LIBRARIES += libselinux
+
 LOCAL_STATIC_LIBRARIES += libselinux
 tune2fs_static_libraries := \
  libext2_com_err \
diff --git a/updater/blockimg.c b/updater/blockimg.c
deleted file mode 100644
index b006d10c5..000000000
--- a/updater/blockimg.c
+++ /dev/null
@@ -1,1953 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <ctype.h>
-#include <errno.h>
-#include <dirent.h>
-#include <fcntl.h>
-#include <inttypes.h>
-#include <libgen.h>
-#include <pthread.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/ioctl.h>
-#include <time.h>
-#include <unistd.h>
-
-#include "applypatch/applypatch.h"
-#include "edify/expr.h"
-#include "mincrypt/sha.h"
-#include "minzip/Hash.h"
-#include "updater.h"
-
-#define BLOCKSIZE 4096
-
-// Set this to 0 to interpret 'erase' transfers to mean do a
-// BLKDISCARD ioctl (the normal behavior).  Set to 1 to interpret
-// erase to mean fill the region with zeroes.
-#define DEBUG_ERASE  0
-
-#ifndef BLKDISCARD
-#define BLKDISCARD _IO(0x12,119)
-#endif
-
-#define STASH_DIRECTORY_BASE "/cache/recovery"
-#define STASH_DIRECTORY_MODE 0700
-#define STASH_FILE_MODE 0600
-
-char* PrintSha1(const uint8_t* digest);
-
-typedef struct {
-    int count;
-    int size;
-    int pos[0];
-} RangeSet;
-
-static RangeSet* parse_range(char* text) {
-    char* save;
-    int num;
-    num = strtol(strtok_r(text, ",", &save), NULL, 0);
-
-    RangeSet* out = malloc(sizeof(RangeSet) + num * sizeof(int));
-    if (out == NULL) {
-        fprintf(stderr, "failed to allocate range of %zu bytes\n",
-                sizeof(RangeSet) + num * sizeof(int));
-        exit(1);
-    }
-    out->count = num / 2;
-    out->size = 0;
-    int i;
-    for (i = 0; i < num; ++i) {
-        out->pos[i] = strtol(strtok_r(NULL, ",", &save), NULL, 0);
-        if (i%2) {
-            out->size += out->pos[i];
-        } else {
-            out->size -= out->pos[i];
-        }
-    }
-
-    return out;
-}
-
-static int range_overlaps(RangeSet* r1, RangeSet* r2) {
-    int i, j, r1_0, r1_1, r2_0, r2_1;
-
-    if (!r1 || !r2) {
-        return 0;
-    }
-
-    for (i = 0; i < r1->count; ++i) {
-        r1_0 = r1->pos[i * 2];
-        r1_1 = r1->pos[i * 2 + 1];
-
-        for (j = 0; j < r2->count; ++j) {
-            r2_0 = r2->pos[j * 2];
-            r2_1 = r2->pos[j * 2 + 1];
-
-            if (!(r2_0 >= r1_1 || r1_0 >= r2_1)) {
-                return 1;
-            }
-        }
-    }
-
-    return 0;
-}
-
-static int read_all(int fd, uint8_t* data, size_t size) {
-    size_t so_far = 0;
-    while (so_far < size) {
-        ssize_t r = TEMP_FAILURE_RETRY(read(fd, data+so_far, size-so_far));
-        if (r == -1) {
-            fprintf(stderr, "read failed: %s\n", strerror(errno));
-            return -1;
-        }
-        so_far += r;
-    }
-    return 0;
-}
-
-static int write_all(int fd, const uint8_t* data, size_t size) {
-    size_t written = 0;
-    while (written < size) {
-        ssize_t w = TEMP_FAILURE_RETRY(write(fd, data+written, size-written));
-        if (w == -1) {
-            fprintf(stderr, "write failed: %s\n", strerror(errno));
-            return -1;
-        }
-        written += w;
-    }
-
-    if (fsync(fd) == -1) {
-        fprintf(stderr, "fsync failed: %s\n", strerror(errno));
-        return -1;
-    }
-
-    return 0;
-}
-
-static bool check_lseek(int fd, off64_t offset, int whence) {
-    off64_t rc = TEMP_FAILURE_RETRY(lseek64(fd, offset, whence));
-    if (rc == -1) {
-        fprintf(stderr, "lseek64 failed: %s\n", strerror(errno));
-        return false;
-    }
-    return true;
-}
-
-static void allocate(size_t size, uint8_t** buffer, size_t* buffer_alloc) {
-    // if the buffer's big enough, reuse it.
-    if (size <= *buffer_alloc) return;
-
-    free(*buffer);
-
-    *buffer = (uint8_t*) malloc(size);
-    if (*buffer == NULL) {
-        fprintf(stderr, "failed to allocate %zu bytes\n", size);
-        exit(1);
-    }
-    *buffer_alloc = size;
-}
-
-typedef struct {
-    int fd;
-    RangeSet* tgt;
-    int p_block;
-    size_t p_remain;
-} RangeSinkState;
-
-static ssize_t RangeSinkWrite(const uint8_t* data, ssize_t size, void* token) {
-    RangeSinkState* rss = (RangeSinkState*) token;
-
-    if (rss->p_remain <= 0) {
-        fprintf(stderr, "range sink write overrun");
-        return 0;
-    }
-
-    ssize_t written = 0;
-    while (size > 0) {
-        size_t write_now = size;
-
-        if (rss->p_remain < write_now) {
-            write_now = rss->p_remain;
-        }
-
-        if (write_all(rss->fd, data, write_now) == -1) {
-            break;
-        }
-
-        data += write_now;
-        size -= write_now;
-
-        rss->p_remain -= write_now;
-        written += write_now;
-
-        if (rss->p_remain == 0) {
-            // move to the next block
-            ++rss->p_block;
-            if (rss->p_block < rss->tgt->count) {
-                rss->p_remain = (rss->tgt->pos[rss->p_block * 2 + 1] -
-                                 rss->tgt->pos[rss->p_block * 2]) * BLOCKSIZE;
-
-                if (!check_lseek(rss->fd, (off64_t)rss->tgt->pos[rss->p_block*2] * BLOCKSIZE,
-                                 SEEK_SET)) {
-                    break;
-                }
-            } else {
-                // we can't write any more; return how many bytes have
-                // been written so far.
-                break;
-            }
-        }
-    }
-
-    return written;
-}
-
-// All of the data for all the 'new' transfers is contained in one
-// file in the update package, concatenated together in the order in
-// which transfers.list will need it.  We want to stream it out of the
-// archive (it's compressed) without writing it to a temp file, but we
-// can't write each section until it's that transfer's turn to go.
-//
-// To achieve this, we expand the new data from the archive in a
-// background thread, and block that threads 'receive uncompressed
-// data' function until the main thread has reached a point where we
-// want some new data to be written.  We signal the background thread
-// with the destination for the data and block the main thread,
-// waiting for the background thread to complete writing that section.
-// Then it signals the main thread to wake up and goes back to
-// blocking waiting for a transfer.
-//
-// NewThreadInfo is the struct used to pass information back and forth
-// between the two threads.  When the main thread wants some data
-// written, it sets rss to the destination location and signals the
-// condition.  When the background thread is done writing, it clears
-// rss and signals the condition again.
-
-typedef struct {
-    ZipArchive* za;
-    const ZipEntry* entry;
-
-    RangeSinkState* rss;
-
-    pthread_mutex_t mu;
-    pthread_cond_t cv;
-} NewThreadInfo;
-
-static bool receive_new_data(const unsigned char* data, int size, void* cookie) {
-    NewThreadInfo* nti = (NewThreadInfo*) cookie;
-
-    while (size > 0) {
-        // Wait for nti->rss to be non-NULL, indicating some of this
-        // data is wanted.
-        pthread_mutex_lock(&nti->mu);
-        while (nti->rss == NULL) {
-            pthread_cond_wait(&nti->cv, &nti->mu);
-        }
-        pthread_mutex_unlock(&nti->mu);
-
-        // At this point nti->rss is set, and we own it.  The main
-        // thread is waiting for it to disappear from nti.
-        ssize_t written = RangeSinkWrite(data, size, nti->rss);
-        data += written;
-        size -= written;
-
-        if (nti->rss->p_block == nti->rss->tgt->count) {
-            // we have written all the bytes desired by this rss.
-
-            pthread_mutex_lock(&nti->mu);
-            nti->rss = NULL;
-            pthread_cond_broadcast(&nti->cv);
-            pthread_mutex_unlock(&nti->mu);
-        }
-    }
-
-    return true;
-}
-
-static void* unzip_new_data(void* cookie) {
-    NewThreadInfo* nti = (NewThreadInfo*) cookie;
-    mzProcessZipEntryContents(nti->za, nti->entry, receive_new_data, nti);
-    return NULL;
-}
-
-static int ReadBlocks(RangeSet* src, uint8_t* buffer, int fd) {
-    int i;
-    size_t p = 0;
-    size_t size;
-
-    if (!src || !buffer) {
-        return -1;
-    }
-
-    for (i = 0; i < src->count; ++i) {
-        if (!check_lseek(fd, (off64_t) src->pos[i * 2] * BLOCKSIZE, SEEK_SET)) {
-            return -1;
-        }
-
-        size = (src->pos[i * 2 + 1] - src->pos[i * 2]) * BLOCKSIZE;
-
-        if (read_all(fd, buffer + p, size) == -1) {
-            return -1;
-        }
-
-        p += size;
-    }
-
-    return 0;
-}
-
-static int WriteBlocks(RangeSet* tgt, uint8_t* buffer, int fd) {
-    int i;
-    size_t p = 0;
-    size_t size;
-
-    if (!tgt || !buffer) {
-        return -1;
-    }
-
-    for (i = 0; i < tgt->count; ++i) {
-        if (!check_lseek(fd, (off64_t) tgt->pos[i * 2] * BLOCKSIZE, SEEK_SET)) {
-            return -1;
-        }
-
-        size = (tgt->pos[i * 2 + 1] - tgt->pos[i * 2]) * BLOCKSIZE;
-
-        if (write_all(fd, buffer + p, size) == -1) {
-            return -1;
-        }
-
-        p += size;
-    }
-
-    return 0;
-}
-
-// Do a source/target load for move/bsdiff/imgdiff in version 1.
-// 'wordsave' is the save_ptr of a strtok_r()-in-progress.  We expect
-// to parse the remainder of the string as:
-//
-//    <src_range> <tgt_range>
-//
-// The source range is loaded into the provided buffer, reallocating
-// it to make it larger if necessary.  The target ranges are returned
-// in *tgt, if tgt is non-NULL.
-
-static int LoadSrcTgtVersion1(char** wordsave, RangeSet** tgt, int* src_blocks,
-                               uint8_t** buffer, size_t* buffer_alloc, int fd) {
-    char* word;
-    int rc;
-
-    word = strtok_r(NULL, " ", wordsave);
-    RangeSet* src = parse_range(word);
-
-    if (tgt != NULL) {
-        word = strtok_r(NULL, " ", wordsave);
-        *tgt = parse_range(word);
-    }
-
-    allocate(src->size * BLOCKSIZE, buffer, buffer_alloc);
-    rc = ReadBlocks(src, *buffer, fd);
-    *src_blocks = src->size;
-
-    free(src);
-    return rc;
-}
-
-static int VerifyBlocks(const char *expected, const uint8_t *buffer,
-                        size_t blocks, int printerror) {
-    char* hexdigest = NULL;
-    int rc = -1;
-    uint8_t digest[SHA_DIGEST_SIZE];
-
-    if (!expected || !buffer) {
-        return rc;
-    }
-
-    SHA_hash(buffer, blocks * BLOCKSIZE, digest);
-    hexdigest = PrintSha1(digest);
-
-    if (hexdigest != NULL) {
-        rc = strcmp(expected, hexdigest);
-
-        if (rc != 0 && printerror) {
-            fprintf(stderr, "failed to verify blocks (expected %s, read %s)\n",
-                expected, hexdigest);
-        }
-
-        free(hexdigest);
-    }
-
-    return rc;
-}
-
-static char* GetStashFileName(const char* base, const char* id, const char* postfix) {
-    char* fn;
-    int len;
-    int res;
-
-    if (base == NULL) {
-        return NULL;
-    }
-
-    if (id == NULL) {
-        id = "";
-    }
-
-    if (postfix == NULL) {
-        postfix = "";
-    }
-
-    len = strlen(STASH_DIRECTORY_BASE) + 1 + strlen(base) + 1 + strlen(id) + strlen(postfix) + 1;
-    fn = malloc(len);
-
-    if (fn == NULL) {
-        fprintf(stderr, "failed to malloc %d bytes for fn\n", len);
-        return NULL;
-    }
-
-    res = snprintf(fn, len, STASH_DIRECTORY_BASE "/%s/%s%s", base, id, postfix);
-
-    if (res < 0 || res >= len) {
-        fprintf(stderr, "failed to format file name (return value %d)\n", res);
-        free(fn);
-        return NULL;
-    }
-
-    return fn;
-}
-
-typedef void (*StashCallback)(const char*, void*);
-
-// Does a best effort enumeration of stash files. Ignores possible non-file
-// items in the stash directory and continues despite of errors. Calls the
-// 'callback' function for each file and passes 'data' to the function as a
-// parameter.
-
-static void EnumerateStash(const char* dirname, StashCallback callback, void* data) {
-    char* fn;
-    DIR* directory;
-    int len;
-    int res;
-    struct dirent* item;
-
-    if (dirname == NULL || callback == NULL) {
-        return;
-    }
-
-    directory = opendir(dirname);
-
-    if (directory == NULL) {
-        if (errno != ENOENT) {
-            fprintf(stderr, "opendir \"%s\" failed: %s\n", dirname, strerror(errno));
-        }
-        return;
-    }
-
-    while ((item = readdir(directory)) != NULL) {
-        if (item->d_type != DT_REG) {
-            continue;
-        }
-
-        len = strlen(dirname) + 1 + strlen(item->d_name) + 1;
-        fn = malloc(len);
-
-        if (fn == NULL) {
-            fprintf(stderr, "failed to malloc %d bytes for fn\n", len);
-            continue;
-        }
-
-        res = snprintf(fn, len, "%s/%s", dirname, item->d_name);
-
-        if (res < 0 || res >= len) {
-            fprintf(stderr, "failed to format file name (return value %d)\n", res);
-            free(fn);
-            continue;
-        }
-
-        callback(fn, data);
-        free(fn);
-    }
-
-    if (closedir(directory) == -1) {
-        fprintf(stderr, "closedir \"%s\" failed: %s\n", dirname, strerror(errno));
-    }
-}
-
-static void UpdateFileSize(const char* fn, void* data) {
-    int* size = (int*) data;
-    struct stat st;
-
-    if (!fn || !data) {
-        return;
-    }
-
-    if (stat(fn, &st) == -1) {
-        fprintf(stderr, "stat \"%s\" failed: %s\n", fn, strerror(errno));
-        return;
-    }
-
-    *size += st.st_size;
-}
-
-// Deletes the stash directory and all files in it. Assumes that it only
-// contains files. There is nothing we can do about unlikely, but possible
-// errors, so they are merely logged.
-
-static void DeleteFile(const char* fn, void* data) {
-    if (fn) {
-        fprintf(stderr, "deleting %s\n", fn);
-
-        if (unlink(fn) == -1 && errno != ENOENT) {
-            fprintf(stderr, "unlink \"%s\" failed: %s\n", fn, strerror(errno));
-        }
-    }
-}
-
-static void DeletePartial(const char* fn, void* data) {
-    if (fn && strstr(fn, ".partial") != NULL) {
-        DeleteFile(fn, data);
-    }
-}
-
-static void DeleteStash(const char* base) {
-    char* dirname;
-
-    if (base == NULL) {
-        return;
-    }
-
-    dirname = GetStashFileName(base, NULL, NULL);
-
-    if (dirname == NULL) {
-        return;
-    }
-
-    fprintf(stderr, "deleting stash %s\n", base);
-    EnumerateStash(dirname, DeleteFile, NULL);
-
-    if (rmdir(dirname) == -1) {
-        if (errno != ENOENT && errno != ENOTDIR) {
-            fprintf(stderr, "rmdir \"%s\" failed: %s\n", dirname, strerror(errno));
-        }
-    }
-
-    free(dirname);
-}
-
-static int LoadStash(const char* base, const char* id, int verify, int* blocks, uint8_t** buffer,
-        size_t* buffer_alloc, int printnoent) {
-    char *fn = NULL;
-    int blockcount = 0;
-    int fd = -1;
-    int rc = -1;
-    int res;
-    struct stat st;
-
-    if (!base || !id || !buffer || !buffer_alloc) {
-        goto lsout;
-    }
-
-    if (!blocks) {
-        blocks = &blockcount;
-    }
-
-    fn = GetStashFileName(base, id, NULL);
-
-    if (fn == NULL) {
-        goto lsout;
-    }
-
-    res = stat(fn, &st);
-
-    if (res == -1) {
-        if (errno != ENOENT || printnoent) {
-            fprintf(stderr, "stat \"%s\" failed: %s\n", fn, strerror(errno));
-        }
-        goto lsout;
-    }
-
-    fprintf(stderr, " loading %s\n", fn);
-
-    if ((st.st_size % BLOCKSIZE) != 0) {
-        fprintf(stderr, "%s size %zd not multiple of block size %d", fn, st.st_size, BLOCKSIZE);
-        goto lsout;
-    }
-
-    fd = TEMP_FAILURE_RETRY(open(fn, O_RDONLY));
-
-    if (fd == -1) {
-        fprintf(stderr, "open \"%s\" failed: %s\n", fn, strerror(errno));
-        goto lsout;
-    }
-
-    allocate(st.st_size, buffer, buffer_alloc);
-
-    if (read_all(fd, *buffer, st.st_size) == -1) {
-        goto lsout;
-    }
-
-    *blocks = st.st_size / BLOCKSIZE;
-
-    if (verify && VerifyBlocks(id, *buffer, *blocks, 1) != 0) {
-        fprintf(stderr, "unexpected contents in %s\n", fn);
-        DeleteFile(fn, NULL);
-        goto lsout;
-    }
-
-    rc = 0;
-
-lsout:
-    if (fd != -1) {
-        close(fd);
-    }
-
-    if (fn) {
-        free(fn);
-    }
-
-    return rc;
-}
-
-static int WriteStash(const char* base, const char* id, int blocks, uint8_t* buffer,
-        int checkspace, int *exists) {
-    char *fn = NULL;
-    char *cn = NULL;
-    int fd = -1;
-    int rc = -1;
-    int dfd = -1;
-    int res;
-    struct stat st;
-
-    if (base == NULL || buffer == NULL) {
-        goto wsout;
-    }
-
-    if (checkspace && CacheSizeCheck(blocks * BLOCKSIZE) != 0) {
-        fprintf(stderr, "not enough space to write stash\n");
-        goto wsout;
-    }
-
-    fn = GetStashFileName(base, id, ".partial");
-    cn = GetStashFileName(base, id, NULL);
-
-    if (fn == NULL || cn == NULL) {
-        goto wsout;
-    }
-
-    if (exists) {
-        res = stat(cn, &st);
-
-        if (res == 0) {
-            // The file already exists and since the name is the hash of the contents,
-            // it's safe to assume the contents are identical (accidental hash collisions
-            // are unlikely)
-            fprintf(stderr, " skipping %d existing blocks in %s\n", blocks, cn);
-            *exists = 1;
-            rc = 0;
-            goto wsout;
-        }
-
-        *exists = 0;
-    }
-
-    fprintf(stderr, " writing %d blocks to %s\n", blocks, cn);
-
-    fd = TEMP_FAILURE_RETRY(open(fn, O_WRONLY | O_CREAT | O_TRUNC | O_SYNC, STASH_FILE_MODE));
-
-    if (fd == -1) {
-        fprintf(stderr, "failed to create \"%s\": %s\n", fn, strerror(errno));
-        goto wsout;
-    }
-
-    if (write_all(fd, buffer, blocks * BLOCKSIZE) == -1) {
-        goto wsout;
-    }
-
-    if (fsync(fd) == -1) {
-        fprintf(stderr, "fsync \"%s\" failed: %s\n", fn, strerror(errno));
-        goto wsout;
-    }
-
-    if (rename(fn, cn) == -1) {
-        fprintf(stderr, "rename(\"%s\", \"%s\") failed: %s\n", fn, cn, strerror(errno));
-        goto wsout;
-    }
-
-    const char* dname;
-    dname = dirname(cn);
-    dfd = TEMP_FAILURE_RETRY(open(dname, O_RDONLY | O_DIRECTORY));
-
-    if (dfd == -1) {
-        fprintf(stderr, "failed to open \"%s\" failed: %s\n", dname, strerror(errno));
-        goto wsout;
-    }
-
-    if (fsync(dfd) == -1) {
-        fprintf(stderr, "fsync \"%s\" failed: %s\n", dname, strerror(errno));
-        goto wsout;
-    }
-
-    rc = 0;
-
-wsout:
-    if (fd != -1) {
-        close(fd);
-    }
-
-    if (dfd != -1) {
-        close(dfd);
-    }
-
-    if (fn) {
-        free(fn);
-    }
-
-    if (cn) {
-        free(cn);
-    }
-
-    return rc;
-}
-
-// Creates a directory for storing stash files and checks if the /cache partition
-// hash enough space for the expected amount of blocks we need to store. Returns
-// >0 if we created the directory, zero if it existed already, and <0 of failure.
-
-static int CreateStash(State* state, int maxblocks, const char* blockdev, char** base) {
-    char* dirname = NULL;
-    const uint8_t* digest;
-    int rc = -1;
-    int res;
-    int size = 0;
-    SHA_CTX ctx;
-    struct stat st;
-
-    if (blockdev == NULL || base == NULL) {
-        goto csout;
-    }
-
-    // Stash directory should be different for each partition to avoid conflicts
-    // when updating multiple partitions at the same time, so we use the hash of
-    // the block device name as the base directory
-    SHA_init(&ctx);
-    SHA_update(&ctx, blockdev, strlen(blockdev));
-    digest = SHA_final(&ctx);
-    *base = PrintSha1(digest);
-
-    if (*base == NULL) {
-        goto csout;
-    }
-
-    dirname = GetStashFileName(*base, NULL, NULL);
-
-    if (dirname == NULL) {
-        goto csout;
-    }
-
-    res = stat(dirname, &st);
-
-    if (res == -1 && errno != ENOENT) {
-        ErrorAbort(state, "stat \"%s\" failed: %s\n", dirname, strerror(errno));
-        goto csout;
-    } else if (res != 0) {
-        fprintf(stderr, "creating stash %s\n", dirname);
-        res = mkdir(dirname, STASH_DIRECTORY_MODE);
-
-        if (res != 0) {
-            ErrorAbort(state, "mkdir \"%s\" failed: %s\n", dirname, strerror(errno));
-            goto csout;
-        }
-
-        if (CacheSizeCheck(maxblocks * BLOCKSIZE) != 0) {
-            ErrorAbort(state, "not enough space for stash\n");
-            goto csout;
-        }
-
-        rc = 1; // Created directory
-        goto csout;
-    }
-
-    fprintf(stderr, "using existing stash %s\n", dirname);
-
-    // If the directory already exists, calculate the space already allocated to
-    // stash files and check if there's enough for all required blocks. Delete any
-    // partially completed stash files first.
-
-    EnumerateStash(dirname, DeletePartial, NULL);
-    EnumerateStash(dirname, UpdateFileSize, &size);
-
-    size = (maxblocks * BLOCKSIZE) - size;
-
-    if (size > 0 && CacheSizeCheck(size) != 0) {
-        ErrorAbort(state, "not enough space for stash (%d more needed)\n", size);
-        goto csout;
-    }
-
-    rc = 0; // Using existing directory
-
-csout:
-    if (dirname) {
-        free(dirname);
-    }
-
-    return rc;
-}
-
-static int SaveStash(const char* base, char** wordsave, uint8_t** buffer, size_t* buffer_alloc,
-                      int fd, int usehash, int* isunresumable) {
-    char *id = NULL;
-    int res = -1;
-    int blocks = 0;
-
-    if (!wordsave || !buffer || !buffer_alloc || !isunresumable) {
-        return -1;
-    }
-
-    id = strtok_r(NULL, " ", wordsave);
-
-    if (id == NULL) {
-        fprintf(stderr, "missing id field in stash command\n");
-        return -1;
-    }
-
-    if (usehash && LoadStash(base, id, 1, &blocks, buffer, buffer_alloc, 0) == 0) {
-        // Stash file already exists and has expected contents. Do not
-        // read from source again, as the source may have been already
-        // overwritten during a previous attempt.
-        return 0;
-    }
-
-    if (LoadSrcTgtVersion1(wordsave, NULL, &blocks, buffer, buffer_alloc, fd) == -1) {
-        return -1;
-    }
-
-    if (usehash && VerifyBlocks(id, *buffer, blocks, 1) != 0) {
-        // Source blocks have unexpected contents. If we actually need this
-        // data later, this is an unrecoverable error. However, the command
-        // that uses the data may have already completed previously, so the
-        // possible failure will occur during source block verification.
-        fprintf(stderr, "failed to load source blocks for stash %s\n", id);
-        return 0;
-    }
-
-    fprintf(stderr, "stashing %d blocks to %s\n", blocks, id);
-    return WriteStash(base, id, blocks, *buffer, 0, NULL);
-}
-
-static int FreeStash(const char* base, const char* id) {
-    char *fn = NULL;
-
-    if (base == NULL || id == NULL) {
-        return -1;
-    }
-
-    fn = GetStashFileName(base, id, NULL);
-
-    if (fn == NULL) {
-        return -1;
-    }
-
-    DeleteFile(fn, NULL);
-    free(fn);
-
-    return 0;
-}
-
-static void MoveRange(uint8_t* dest, RangeSet* locs, const uint8_t* source) {
-    // source contains packed data, which we want to move to the
-    // locations given in *locs in the dest buffer.  source and dest
-    // may be the same buffer.
-
-    int start = locs->size;
-    int i;
-    for (i = locs->count-1; i >= 0; --i) {
-        int blocks = locs->pos[i*2+1] - locs->pos[i*2];
-        start -= blocks;
-        memmove(dest + (locs->pos[i*2] * BLOCKSIZE), source + (start * BLOCKSIZE),
-                blocks * BLOCKSIZE);
-    }
-}
-
-// Do a source/target load for move/bsdiff/imgdiff in version 2.
-// 'wordsave' is the save_ptr of a strtok_r()-in-progress.  We expect
-// to parse the remainder of the string as one of:
-//
-//    <tgt_range> <src_block_count> <src_range>
-//        (loads data from source image only)
-//
-//    <tgt_range> <src_block_count> - <[stash_id:stash_range] ...>
-//        (loads data from stashes only)
-//
-//    <tgt_range> <src_block_count> <src_range> <src_loc> <[stash_id:stash_range] ...>
-//        (loads data from both source image and stashes)
-//
-// On return, buffer is filled with the loaded source data (rearranged
-// and combined with stashed data as necessary).  buffer may be
-// reallocated if needed to accommodate the source data.  *tgt is the
-// target RangeSet.  Any stashes required are loaded using LoadStash.
-
-static int LoadSrcTgtVersion2(char** wordsave, RangeSet** tgt, int* src_blocks,
-                               uint8_t** buffer, size_t* buffer_alloc, int fd,
-                               const char* stashbase, int* overlap) {
-    char* word;
-    char* colonsave;
-    char* colon;
-    int id;
-    int res;
-    RangeSet* locs;
-    size_t stashalloc = 0;
-    uint8_t* stash = NULL;
-
-    if (tgt != NULL) {
-        word = strtok_r(NULL, " ", wordsave);
-        *tgt = parse_range(word);
-    }
-
-    word = strtok_r(NULL, " ", wordsave);
-    *src_blocks = strtol(word, NULL, 0);
-
-    allocate(*src_blocks * BLOCKSIZE, buffer, buffer_alloc);
-
-    word = strtok_r(NULL, " ", wordsave);
-    if (word[0] == '-' && word[1] == '\0') {
-        // no source ranges, only stashes
-    } else {
-        RangeSet* src = parse_range(word);
-        res = ReadBlocks(src, *buffer, fd);
-
-        if (overlap && tgt) {
-            *overlap = range_overlaps(src, *tgt);
-        }
-
-        free(src);
-
-        if (res == -1) {
-            return -1;
-        }
-
-        word = strtok_r(NULL, " ", wordsave);
-        if (word == NULL) {
-            // no stashes, only source range
-            return 0;
-        }
-
-        locs = parse_range(word);
-        MoveRange(*buffer, locs, *buffer);
-        free(locs);
-    }
-
-    while ((word = strtok_r(NULL, " ", wordsave)) != NULL) {
-        // Each word is a an index into the stash table, a colon, and
-        // then a rangeset describing where in the source block that
-        // stashed data should go.
-        colonsave = NULL;
-        colon = strtok_r(word, ":", &colonsave);
-
-        res = LoadStash(stashbase, colon, 0, NULL, &stash, &stashalloc, 1);
-
-        if (res == -1) {
-            // These source blocks will fail verification if used later, but we
-            // will let the caller decide if this is a fatal failure
-            fprintf(stderr, "failed to load stash %s\n", colon);
-            continue;
-        }
-
-        colon = strtok_r(NULL, ":", &colonsave);
-        locs = parse_range(colon);
-
-        MoveRange(*buffer, locs, stash);
-        free(locs);
-    }
-
-    if (stash) {
-        free(stash);
-    }
-
-    return 0;
-}
-
-// Parameters for transfer list command functions
-typedef struct {
-    char* cmdname;
-    char* cpos;
-    char* freestash;
-    char* stashbase;
-    int canwrite;
-    int createdstash;
-    int fd;
-    int foundwrites;
-    int isunresumable;
-    int version;
-    int written;
-    NewThreadInfo nti;
-    pthread_t thread;
-    size_t bufsize;
-    uint8_t* buffer;
-    uint8_t* patch_start;
-} CommandParameters;
-
-// Do a source/target load for move/bsdiff/imgdiff in version 3.
-//
-// Parameters are the same as for LoadSrcTgtVersion2, except for 'onehash', which
-// tells the function whether to expect separate source and targe block hashes, or
-// if they are both the same and only one hash should be expected, and
-// 'isunresumable', which receives a non-zero value if block verification fails in
-// a way that the update cannot be resumed anymore.
-//
-// If the function is unable to load the necessary blocks or their contents don't
-// match the hashes, the return value is -1 and the command should be aborted.
-//
-// If the return value is 1, the command has already been completed according to
-// the contents of the target blocks, and should not be performed again.
-//
-// If the return value is 0, source blocks have expected content and the command
-// can be performed.
-
-static int LoadSrcTgtVersion3(CommandParameters* params, RangeSet** tgt, int* src_blocks,
-                              int onehash, int* overlap) {
-    char* srchash = NULL;
-    char* tgthash = NULL;
-    int stash_exists = 0;
-    int overlap_blocks = 0;
-    int rc = -1;
-    uint8_t* tgtbuffer = NULL;
-
-    if (!params|| !tgt || !src_blocks || !overlap) {
-        goto v3out;
-    }
-
-    srchash = strtok_r(NULL, " ", &params->cpos);
-
-    if (srchash == NULL) {
-        fprintf(stderr, "missing source hash\n");
-        goto v3out;
-    }
-
-    if (onehash) {
-        tgthash = srchash;
-    } else {
-        tgthash = strtok_r(NULL, " ", &params->cpos);
-
-        if (tgthash == NULL) {
-            fprintf(stderr, "missing target hash\n");
-            goto v3out;
-        }
-    }
-
-    if (LoadSrcTgtVersion2(&params->cpos, tgt, src_blocks, &params->buffer, &params->bufsize,
-            params->fd, params->stashbase, overlap) == -1) {
-        goto v3out;
-    }
-
-    tgtbuffer = (uint8_t*) malloc((*tgt)->size * BLOCKSIZE);
-
-    if (tgtbuffer == NULL) {
-        fprintf(stderr, "failed to allocate %d bytes\n", (*tgt)->size * BLOCKSIZE);
-        goto v3out;
-    }
-
-    if (ReadBlocks(*tgt, tgtbuffer, params->fd) == -1) {
-        goto v3out;
-    }
-
-    if (VerifyBlocks(tgthash, tgtbuffer, (*tgt)->size, 0) == 0) {
-        // Target blocks already have expected content, command should be skipped
-        rc = 1;
-        goto v3out;
-    }
-
-    if (VerifyBlocks(srchash, params->buffer, *src_blocks, 1) == 0) {
-        // If source and target blocks overlap, stash the source blocks so we can
-        // resume from possible write errors
-        if (*overlap) {
-            fprintf(stderr, "stashing %d overlapping blocks to %s\n", *src_blocks,
-                srchash);
-
-            if (WriteStash(params->stashbase, srchash, *src_blocks, params->buffer, 1,
-                    &stash_exists) != 0) {
-                fprintf(stderr, "failed to stash overlapping source blocks\n");
-                goto v3out;
-            }
-
-            // Can be deleted when the write has completed
-            if (!stash_exists) {
-                params->freestash = srchash;
-            }
-        }
-
-        // Source blocks have expected content, command can proceed
-        rc = 0;
-        goto v3out;
-    }
-
-    if (*overlap && LoadStash(params->stashbase, srchash, 1, NULL, &params->buffer,
-                        &params->bufsize, 1) == 0) {
-        // Overlapping source blocks were previously stashed, command can proceed.
-        // We are recovering from an interrupted command, so we don't know if the
-        // stash can safely be deleted after this command.
-        rc = 0;
-        goto v3out;
-    }
-
-    // Valid source data not available, update cannot be resumed
-    fprintf(stderr, "partition has unexpected contents\n");
-    params->isunresumable = 1;
-
-v3out:
-    if (tgtbuffer) {
-        free(tgtbuffer);
-    }
-
-    return rc;
-}
-
-static int PerformCommandMove(CommandParameters* params) {
-    int blocks = 0;
-    int overlap = 0;
-    int rc = -1;
-    int status = 0;
-    RangeSet* tgt = NULL;
-
-    if (!params) {
-        goto pcmout;
-    }
-
-    if (params->version == 1) {
-        status = LoadSrcTgtVersion1(&params->cpos, &tgt, &blocks, &params->buffer,
-                    &params->bufsize, params->fd);
-    } else if (params->version == 2) {
-        status = LoadSrcTgtVersion2(&params->cpos, &tgt, &blocks, &params->buffer,
-                    &params->bufsize, params->fd, params->stashbase, NULL);
-    } else if (params->version >= 3) {
-        status = LoadSrcTgtVersion3(params, &tgt, &blocks, 1, &overlap);
-    }
-
-    if (status == -1) {
-        fprintf(stderr, "failed to read blocks for move\n");
-        goto pcmout;
-    }
-
-    if (status == 0) {
-        params->foundwrites = 1;
-    } else if (params->foundwrites) {
-        fprintf(stderr, "warning: commands executed out of order [%s]\n", params->cmdname);
-    }
-
-    if (params->canwrite) {
-        if (status == 0) {
-            fprintf(stderr, "  moving %d blocks\n", blocks);
-
-            if (WriteBlocks(tgt, params->buffer, params->fd) == -1) {
-                goto pcmout;
-            }
-        } else {
-            fprintf(stderr, "skipping %d already moved blocks\n", blocks);
-        }
-
-    }
-
-    if (params->freestash) {
-        FreeStash(params->stashbase, params->freestash);
-        params->freestash = NULL;
-    }
-
-    params->written += tgt->size;
-    rc = 0;
-
-pcmout:
-    if (tgt) {
-        free(tgt);
-    }
-
-    return rc;
-}
-
-static int PerformCommandStash(CommandParameters* params) {
-    if (!params) {
-        return -1;
-    }
-
-    return SaveStash(params->stashbase, &params->cpos, &params->buffer, &params->bufsize,
-                params->fd, (params->version >= 3), &params->isunresumable);
-}
-
-static int PerformCommandFree(CommandParameters* params) {
-    if (!params) {
-        return -1;
-    }
-
-    if (params->createdstash || params->canwrite) {
-        return FreeStash(params->stashbase, params->cpos);
-    }
-
-    return 0;
-}
-
-static int PerformCommandZero(CommandParameters* params) {
-    char* range = NULL;
-    int i;
-    int j;
-    int rc = -1;
-    RangeSet* tgt = NULL;
-
-    if (!params) {
-        goto pczout;
-    }
-
-    range = strtok_r(NULL, " ", &params->cpos);
-
-    if (range == NULL) {
-        fprintf(stderr, "missing target blocks for zero\n");
-        goto pczout;
-    }
-
-    tgt = parse_range(range);
-
-    fprintf(stderr, "  zeroing %d blocks\n", tgt->size);
-
-    allocate(BLOCKSIZE, &params->buffer, &params->bufsize);
-    memset(params->buffer, 0, BLOCKSIZE);
-
-    if (params->canwrite) {
-        for (i = 0; i < tgt->count; ++i) {
-            if (!check_lseek(params->fd, (off64_t) tgt->pos[i * 2] * BLOCKSIZE, SEEK_SET)) {
-                goto pczout;
-            }
-
-            for (j = tgt->pos[i * 2]; j < tgt->pos[i * 2 + 1]; ++j) {
-                if (write_all(params->fd, params->buffer, BLOCKSIZE) == -1) {
-                    goto pczout;
-                }
-            }
-        }
-    }
-
-    if (params->cmdname[0] == 'z') {
-        // Update only for the zero command, as the erase command will call
-        // this if DEBUG_ERASE is defined.
-        params->written += tgt->size;
-    }
-
-    rc = 0;
-
-pczout:
-    if (tgt) {
-        free(tgt);
-    }
-
-    return rc;
-}
-
-static int PerformCommandNew(CommandParameters* params) {
-    char* range = NULL;
-    int rc = -1;
-    RangeSet* tgt = NULL;
-    RangeSinkState rss;
-
-    if (!params) {
-        goto pcnout;
-    }
-
-    range = strtok_r(NULL, " ", &params->cpos);
-
-    if (range == NULL) {
-        goto pcnout;
-    }
-
-    tgt = parse_range(range);
-
-    if (params->canwrite) {
-        fprintf(stderr, " writing %d blocks of new data\n", tgt->size);
-
-        rss.fd = params->fd;
-        rss.tgt = tgt;
-        rss.p_block = 0;
-        rss.p_remain = (tgt->pos[1] - tgt->pos[0]) * BLOCKSIZE;
-
-        if (!check_lseek(params->fd, (off64_t) tgt->pos[0] * BLOCKSIZE, SEEK_SET)) {
-            goto pcnout;
-        }
-
-        pthread_mutex_lock(&params->nti.mu);
-        params->nti.rss = &rss;
-        pthread_cond_broadcast(&params->nti.cv);
-
-        while (params->nti.rss) {
-            pthread_cond_wait(&params->nti.cv, &params->nti.mu);
-        }
-
-        pthread_mutex_unlock(&params->nti.mu);
-    }
-
-    params->written += tgt->size;
-    rc = 0;
-
-pcnout:
-    if (tgt) {
-        free(tgt);
-    }
-
-    return rc;
-}
-
-static int PerformCommandDiff(CommandParameters* params) {
-    char* logparams = NULL;
-    char* value = NULL;
-    int blocks = 0;
-    int overlap = 0;
-    int rc = -1;
-    int status = 0;
-    RangeSet* tgt = NULL;
-    RangeSinkState rss;
-    size_t len = 0;
-    size_t offset = 0;
-    Value patch_value;
-
-    if (!params) {
-        goto pcdout;
-    }
-
-    logparams = strdup(params->cpos);
-    value = strtok_r(NULL, " ", &params->cpos);
-
-    if (value == NULL) {
-        fprintf(stderr, "missing patch offset for %s\n", params->cmdname);
-        goto pcdout;
-    }
-
-    offset = strtoul(value, NULL, 0);
-
-    value = strtok_r(NULL, " ", &params->cpos);
-
-    if (value == NULL) {
-        fprintf(stderr, "missing patch length for %s\n", params->cmdname);
-        goto pcdout;
-    }
-
-    len = strtoul(value, NULL, 0);
-
-    if (params->version == 1) {
-        status = LoadSrcTgtVersion1(&params->cpos, &tgt, &blocks, &params->buffer,
-                    &params->bufsize, params->fd);
-    } else if (params->version == 2) {
-        status = LoadSrcTgtVersion2(&params->cpos, &tgt, &blocks, &params->buffer,
-                    &params->bufsize, params->fd, params->stashbase, NULL);
-    } else if (params->version >= 3) {
-        status = LoadSrcTgtVersion3(params, &tgt, &blocks, 0, &overlap);
-    }
-
-    if (status == -1) {
-        fprintf(stderr, "failed to read blocks for diff\n");
-        goto pcdout;
-    }
-
-    if (status == 0) {
-        params->foundwrites = 1;
-    } else if (params->foundwrites) {
-        fprintf(stderr, "warning: commands executed out of order [%s]\n", params->cmdname);
-    }
-
-    if (params->canwrite) {
-        if (status == 0) {
-            fprintf(stderr, "patching %d blocks to %d\n", blocks, tgt->size);
-
-            patch_value.type = VAL_BLOB;
-            patch_value.size = len;
-            patch_value.data = (char*) (params->patch_start + offset);
-
-            rss.fd = params->fd;
-            rss.tgt = tgt;
-            rss.p_block = 0;
-            rss.p_remain = (tgt->pos[1] - tgt->pos[0]) * BLOCKSIZE;
-
-            if (!check_lseek(params->fd, (off64_t) tgt->pos[0] * BLOCKSIZE, SEEK_SET)) {
-                goto pcdout;
-            }
-
-            if (params->cmdname[0] == 'i') {      // imgdiff
-                ApplyImagePatch(params->buffer, blocks * BLOCKSIZE, &patch_value,
-                    &RangeSinkWrite, &rss, NULL, NULL);
-            } else {
-                ApplyBSDiffPatch(params->buffer, blocks * BLOCKSIZE, &patch_value,
-                    0, &RangeSinkWrite, &rss, NULL);
-            }
-
-            // We expect the output of the patcher to fill the tgt ranges exactly.
-            if (rss.p_block != tgt->count || rss.p_remain != 0) {
-                fprintf(stderr, "range sink underrun?\n");
-            }
-        } else {
-            fprintf(stderr, "skipping %d blocks already patched to %d [%s]\n",
-                blocks, tgt->size, logparams);
-        }
-    }
-
-    if (params->freestash) {
-        FreeStash(params->stashbase, params->freestash);
-        params->freestash = NULL;
-    }
-
-    params->written += tgt->size;
-    rc = 0;
-
-pcdout:
-    if (logparams) {
-        free(logparams);
-    }
-
-    if (tgt) {
-        free(tgt);
-    }
-
-    return rc;
-}
-
-static int PerformCommandErase(CommandParameters* params) {
-    char* range = NULL;
-    int i;
-    int rc = -1;
-    RangeSet* tgt = NULL;
-    struct stat st;
-    uint64_t blocks[2];
-
-    if (DEBUG_ERASE) {
-        return PerformCommandZero(params);
-    }
-
-    if (!params) {
-        goto pceout;
-    }
-
-    if (fstat(params->fd, &st) == -1) {
-        fprintf(stderr, "failed to fstat device to erase: %s\n", strerror(errno));
-        goto pceout;
-    }
-
-    if (!S_ISBLK(st.st_mode)) {
-        fprintf(stderr, "not a block device; skipping erase\n");
-        goto pceout;
-    }
-
-    range = strtok_r(NULL, " ", &params->cpos);
-
-    if (range == NULL) {
-        fprintf(stderr, "missing target blocks for zero\n");
-        goto pceout;
-    }
-
-    tgt = parse_range(range);
-
-    if (params->canwrite) {
-        fprintf(stderr, " erasing %d blocks\n", tgt->size);
-
-        for (i = 0; i < tgt->count; ++i) {
-            // offset in bytes
-            blocks[0] = tgt->pos[i * 2] * (uint64_t) BLOCKSIZE;
-            // length in bytes
-            blocks[1] = (tgt->pos[i * 2 + 1] - tgt->pos[i * 2]) * (uint64_t) BLOCKSIZE;
-
-            if (ioctl(params->fd, BLKDISCARD, &blocks) == -1) {
-                fprintf(stderr, "BLKDISCARD ioctl failed: %s\n", strerror(errno));
-                goto pceout;
-            }
-        }
-    }
-
-    rc = 0;
-
-pceout:
-    if (tgt) {
-        free(tgt);
-    }
-
-    return rc;
-}
-
-// Definitions for transfer list command functions
-typedef int (*CommandFunction)(CommandParameters*);
-
-typedef struct {
-    const char* name;
-    CommandFunction f;
-} Command;
-
-// CompareCommands and CompareCommandNames are for the hash table
-
-static int CompareCommands(const void* c1, const void* c2) {
-    return strcmp(((const Command*) c1)->name, ((const Command*) c2)->name);
-}
-
-static int CompareCommandNames(const void* c1, const void* c2) {
-    return strcmp(((const Command*) c1)->name, (const char*) c2);
-}
-
-// HashString is used to hash command names for the hash table
-
-static unsigned int HashString(const char *s) {
-    unsigned int hash = 0;
-    if (s) {
-        while (*s) {
-            hash = hash * 33 + *s++;
-        }
-    }
-    return hash;
-}
-
-// args:
-//    - block device (or file) to modify in-place
-//    - transfer list (blob)
-//    - new data stream (filename within package.zip)
-//    - patch stream (filename within package.zip, must be uncompressed)
-
-static Value* PerformBlockImageUpdate(const char* name, State* state, int argc, Expr* argv[],
-            const Command* commands, int cmdcount, int dryrun) {
-
-    char* line = NULL;
-    char* linesave = NULL;
-    char* logcmd = NULL;
-    char* transfer_list = NULL;
-    CommandParameters params;
-    const Command* cmd = NULL;
-    const ZipEntry* new_entry = NULL;
-    const ZipEntry* patch_entry = NULL;
-    FILE* cmd_pipe = NULL;
-    HashTable* cmdht = NULL;
-    int i;
-    int res;
-    int rc = -1;
-    int stash_max_blocks = 0;
-    int total_blocks = 0;
-    pthread_attr_t attr;
-    unsigned int cmdhash;
-    UpdaterInfo* ui = NULL;
-    Value* blockdev_filename = NULL;
-    Value* new_data_fn = NULL;
-    Value* patch_data_fn = NULL;
-    Value* transfer_list_value = NULL;
-    ZipArchive* za = NULL;
-
-    memset(&params, 0, sizeof(params));
-    params.canwrite = !dryrun;
-
-    fprintf(stderr, "performing %s\n", dryrun ? "verification" : "update");
-
-    if (ReadValueArgs(state, argv, 4, &blockdev_filename, &transfer_list_value,
-            &new_data_fn, &patch_data_fn) < 0) {
-        goto pbiudone;
-    }
-
-    if (blockdev_filename->type != VAL_STRING) {
-        ErrorAbort(state, "blockdev_filename argument to %s must be string", name);
-        goto pbiudone;
-    }
-    if (transfer_list_value->type != VAL_BLOB) {
-        ErrorAbort(state, "transfer_list argument to %s must be blob", name);
-        goto pbiudone;
-    }
-    if (new_data_fn->type != VAL_STRING) {
-        ErrorAbort(state, "new_data_fn argument to %s must be string", name);
-        goto pbiudone;
-    }
-    if (patch_data_fn->type != VAL_STRING) {
-        ErrorAbort(state, "patch_data_fn argument to %s must be string", name);
-        goto pbiudone;
-    }
-
-    ui = (UpdaterInfo*) state->cookie;
-
-    if (ui == NULL) {
-        goto pbiudone;
-    }
-
-    cmd_pipe = ui->cmd_pipe;
-    za = ui->package_zip;
-
-    if (cmd_pipe == NULL || za == NULL) {
-        goto pbiudone;
-    }
-
-    patch_entry = mzFindZipEntry(za, patch_data_fn->data);
-
-    if (patch_entry == NULL) {
-        fprintf(stderr, "%s(): no file \"%s\" in package", name, patch_data_fn->data);
-        goto pbiudone;
-    }
-
-    params.patch_start = ui->package_zip_addr + mzGetZipEntryOffset(patch_entry);
-    new_entry = mzFindZipEntry(za, new_data_fn->data);
-
-    if (new_entry == NULL) {
-        fprintf(stderr, "%s(): no file \"%s\" in package", name, new_data_fn->data);
-        goto pbiudone;
-    }
-
-    params.fd = TEMP_FAILURE_RETRY(open(blockdev_filename->data, O_RDWR));
-
-    if (params.fd == -1) {
-        fprintf(stderr, "open \"%s\" failed: %s\n", blockdev_filename->data, strerror(errno));
-        goto pbiudone;
-    }
-
-    if (params.canwrite) {
-        params.nti.za = za;
-        params.nti.entry = new_entry;
-
-        pthread_mutex_init(&params.nti.mu, NULL);
-        pthread_cond_init(&params.nti.cv, NULL);
-        pthread_attr_init(&attr);
-        pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-
-        int error = pthread_create(&params.thread, &attr, unzip_new_data, &params.nti);
-        if (error != 0) {
-            fprintf(stderr, "pthread_create failed: %s\n", strerror(error));
-            goto pbiudone;
-        }
-    }
-
-    // The data in transfer_list_value is not necessarily null-terminated, so we need
-    // to copy it to a new buffer and add the null that strtok_r will need.
-    transfer_list = malloc(transfer_list_value->size + 1);
-
-    if (transfer_list == NULL) {
-        fprintf(stderr, "failed to allocate %zd bytes for transfer list\n",
-            transfer_list_value->size + 1);
-        goto pbiudone;
-    }
-
-    memcpy(transfer_list, transfer_list_value->data, transfer_list_value->size);
-    transfer_list[transfer_list_value->size] = '\0';
-
-    // First line in transfer list is the version number
-    line = strtok_r(transfer_list, "\n", &linesave);
-    params.version = strtol(line, NULL, 0);
-
-    if (params.version < 1 || params.version > 3) {
-        fprintf(stderr, "unexpected transfer list version [%s]\n", line);
-        goto pbiudone;
-    }
-
-    fprintf(stderr, "blockimg version is %d\n", params.version);
-
-    // Second line in transfer list is the total number of blocks we expect to write
-    line = strtok_r(NULL, "\n", &linesave);
-    total_blocks = strtol(line, NULL, 0);
-
-    if (total_blocks < 0) {
-        ErrorAbort(state, "unexpected block count [%s]\n", line);
-        goto pbiudone;
-    } else if (total_blocks == 0) {
-        rc = 0;
-        goto pbiudone;
-    }
-
-    if (params.version >= 2) {
-        // Third line is how many stash entries are needed simultaneously
-        line = strtok_r(NULL, "\n", &linesave);
-        fprintf(stderr, "maximum stash entries %s\n", line);
-
-        // Fourth line is the maximum number of blocks that will be stashed simultaneously
-        line = strtok_r(NULL, "\n", &linesave);
-        stash_max_blocks = strtol(line, NULL, 0);
-
-        if (stash_max_blocks < 0) {
-            ErrorAbort(state, "unexpected maximum stash blocks [%s]\n", line);
-            goto pbiudone;
-        }
-
-        if (stash_max_blocks >= 0) {
-            res = CreateStash(state, stash_max_blocks, blockdev_filename->data,
-                    &params.stashbase);
-
-            if (res == -1) {
-                goto pbiudone;
-            }
-
-            params.createdstash = res;
-        }
-    }
-
-    // Build a hash table of the available commands
-    cmdht = mzHashTableCreate(cmdcount, NULL);
-
-    for (i = 0; i < cmdcount; ++i) {
-        cmdhash = HashString(commands[i].name);
-        mzHashTableLookup(cmdht, cmdhash, (void*) &commands[i], CompareCommands, true);
-    }
-
-    // Subsequent lines are all individual transfer commands
-    for (line = strtok_r(NULL, "\n", &linesave); line;
-         line = strtok_r(NULL, "\n", &linesave)) {
-
-        logcmd = strdup(line);
-        params.cmdname = strtok_r(line, " ", &params.cpos);
-
-        if (params.cmdname == NULL) {
-            fprintf(stderr, "missing command [%s]\n", line);
-            goto pbiudone;
-        }
-
-        cmdhash = HashString(params.cmdname);
-        cmd = (const Command*) mzHashTableLookup(cmdht, cmdhash, params.cmdname,
-                                    CompareCommandNames, false);
-
-        if (cmd == NULL) {
-            fprintf(stderr, "unexpected command [%s]\n", params.cmdname);
-            goto pbiudone;
-        }
-
-        if (cmd->f != NULL && cmd->f(&params) == -1) {
-            fprintf(stderr, "failed to execute command [%s]\n",
-                logcmd ? logcmd : params.cmdname);
-            goto pbiudone;
-        }
-
-        if (logcmd) {
-            free(logcmd);
-            logcmd = NULL;
-        }
-
-        if (params.canwrite) {
-            fprintf(cmd_pipe, "set_progress %.4f\n", (double) params.written / total_blocks);
-            fflush(cmd_pipe);
-        }
-    }
-
-    if (params.canwrite) {
-        pthread_join(params.thread, NULL);
-
-        fprintf(stderr, "wrote %d blocks; expected %d\n", params.written, total_blocks);
-        fprintf(stderr, "max alloc needed was %zu\n", params.bufsize);
-
-        // Delete stash only after successfully completing the update, as it
-        // may contain blocks needed to complete the update later.
-        DeleteStash(params.stashbase);
-    } else {
-        fprintf(stderr, "verified partition contents; update may be resumed\n");
-    }
-
-    rc = 0;
-
-pbiudone:
-    if (params.fd != -1) {
-        if (fsync(params.fd) == -1) {
-            fprintf(stderr, "fsync failed: %s\n", strerror(errno));
-        }
-        close(params.fd);
-    }
-
-    if (logcmd) {
-        free(logcmd);
-    }
-
-    if (cmdht) {
-        mzHashTableFree(cmdht);
-    }
-
-    if (params.buffer) {
-        free(params.buffer);
-    }
-
-    if (transfer_list) {
-        free(transfer_list);
-    }
-
-    if (blockdev_filename) {
-        FreeValue(blockdev_filename);
-    }
-
-    if (transfer_list_value) {
-        FreeValue(transfer_list_value);
-    }
-
-    if (new_data_fn) {
-        FreeValue(new_data_fn);
-    }
-
-    if (patch_data_fn) {
-        FreeValue(patch_data_fn);
-    }
-
-    // Only delete the stash if the update cannot be resumed, or it's
-    // a verification run and we created the stash.
-    if (params.isunresumable || (!params.canwrite && params.createdstash)) {
-        DeleteStash(params.stashbase);
-    }
-
-    if (params.stashbase) {
-        free(params.stashbase);
-    }
-
-    return StringValue(rc == 0 ? strdup("t") : strdup(""));
-}
-
-// The transfer list is a text file containing commands to
-// transfer data from one place to another on the target
-// partition.  We parse it and execute the commands in order:
-//
-//    zero [rangeset]
-//      - fill the indicated blocks with zeros
-//
-//    new [rangeset]
-//      - fill the blocks with data read from the new_data file
-//
-//    erase [rangeset]
-//      - mark the given blocks as empty
-//
-//    move <...>
-//    bsdiff <patchstart> <patchlen> <...>
-//    imgdiff <patchstart> <patchlen> <...>
-//      - read the source blocks, apply a patch (or not in the
-//        case of move), write result to target blocks.  bsdiff or
-//        imgdiff specifies the type of patch; move means no patch
-//        at all.
-//
-//        The format of <...> differs between versions 1 and 2;
-//        see the LoadSrcTgtVersion{1,2}() functions for a
-//        description of what's expected.
-//
-//    stash <stash_id> <src_range>
-//      - (version 2+ only) load the given source range and stash
-//        the data in the given slot of the stash table.
-//
-// The creator of the transfer list will guarantee that no block
-// is read (ie, used as the source for a patch or move) after it
-// has been written.
-//
-// In version 2, the creator will guarantee that a given stash is
-// loaded (with a stash command) before it's used in a
-// move/bsdiff/imgdiff command.
-//
-// Within one command the source and target ranges may overlap so
-// in general we need to read the entire source into memory before
-// writing anything to the target blocks.
-//
-// All the patch data is concatenated into one patch_data file in
-// the update package.  It must be stored uncompressed because we
-// memory-map it in directly from the archive.  (Since patches are
-// already compressed, we lose very little by not compressing
-// their concatenation.)
-//
-// In version 3, commands that read data from the partition (i.e.
-// move/bsdiff/imgdiff/stash) have one or more additional hashes
-// before the range parameters, which are used to check if the
-// command has already been completed and verify the integrity of
-// the source data.
-
-Value* BlockImageVerifyFn(const char* name, State* state, int argc, Expr* argv[]) {
-    // Commands which are not tested are set to NULL to skip them completely
-    const Command commands[] = {
-        { "bsdiff",     PerformCommandDiff  },
-        { "erase",      NULL                },
-        { "free",       PerformCommandFree  },
-        { "imgdiff",    PerformCommandDiff  },
-        { "move",       PerformCommandMove  },
-        { "new",        NULL                },
-        { "stash",      PerformCommandStash },
-        { "zero",       NULL                }
-    };
-
-    // Perform a dry run without writing to test if an update can proceed
-    return PerformBlockImageUpdate(name, state, argc, argv, commands,
-                sizeof(commands) / sizeof(commands[0]), 1);
-}
-
-Value* BlockImageUpdateFn(const char* name, State* state, int argc, Expr* argv[]) {
-    const Command commands[] = {
-        { "bsdiff",     PerformCommandDiff  },
-        { "erase",      PerformCommandErase },
-        { "free",       PerformCommandFree  },
-        { "imgdiff",    PerformCommandDiff  },
-        { "move",       PerformCommandMove  },
-        { "new",        PerformCommandNew   },
-        { "stash",      PerformCommandStash },
-        { "zero",       PerformCommandZero  }
-    };
-
-    return PerformBlockImageUpdate(name, state, argc, argv, commands,
-                sizeof(commands) / sizeof(commands[0]), 0);
-}
-
-Value* RangeSha1Fn(const char* name, State* state, int argc, Expr* argv[]) {
-    Value* blockdev_filename;
-    Value* ranges;
-    const uint8_t* digest = NULL;
-    if (ReadValueArgs(state, argv, 2, &blockdev_filename, &ranges) < 0) {
-        return NULL;
-    }
-
-    if (blockdev_filename->type != VAL_STRING) {
-        ErrorAbort(state, "blockdev_filename argument to %s must be string", name);
-        goto done;
-    }
-    if (ranges->type != VAL_STRING) {
-        ErrorAbort(state, "ranges argument to %s must be string", name);
-        goto done;
-    }
-
-    int fd = open(blockdev_filename->data, O_RDWR);
-    if (fd < 0) {
-        ErrorAbort(state, "open \"%s\" failed: %s", blockdev_filename->data, strerror(errno));
-        goto done;
-    }
-
-    RangeSet* rs = parse_range(ranges->data);
-    uint8_t buffer[BLOCKSIZE];
-
-    SHA_CTX ctx;
-    SHA_init(&ctx);
-
-    int i, j;
-    for (i = 0; i < rs->count; ++i) {
-        if (!check_lseek(fd, (off64_t)rs->pos[i*2] * BLOCKSIZE, SEEK_SET)) {
-            ErrorAbort(state, "failed to seek %s: %s", blockdev_filename->data,
-                strerror(errno));
-            goto done;
-        }
-
-        for (j = rs->pos[i*2]; j < rs->pos[i*2+1]; ++j) {
-            if (read_all(fd, buffer, BLOCKSIZE) == -1) {
-                ErrorAbort(state, "failed to read %s: %s", blockdev_filename->data,
-                    strerror(errno));
-                goto done;
-            }
-
-            SHA_update(&ctx, buffer, BLOCKSIZE);
-        }
-    }
-    digest = SHA_final(&ctx);
-    close(fd);
-
-  done:
-    FreeValue(blockdev_filename);
-    FreeValue(ranges);
-    if (digest == NULL) {
-        return StringValue(strdup(""));
-    } else {
-        return StringValue(PrintSha1(digest));
-    }
-}
-
-void RegisterBlockImageFunctions() {
-    RegisterFunction("block_image_verify", BlockImageVerifyFn);
-    RegisterFunction("block_image_update", BlockImageUpdateFn);
-    RegisterFunction("range_sha1", RangeSha1Fn);
-}
diff --git a/updater/blockimg.cpp b/updater/blockimg.cpp
new file mode 100644
index 000000000..a80180a9a
--- /dev/null
+++ b/updater/blockimg.cpp
@@ -0,0 +1,1918 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/fs.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/ioctl.h>
+#include <time.h>
+#include <unistd.h>
+#include <fec/io.h>
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <android-base/parseint.h>
+#include <android-base/strings.h>
+
+#include "applypatch/applypatch.h"
+#include "edify/expr.h"
+#include "error_code.h"
+#include "install.h"
+#include "openssl/sha.h"
+#include "minzip/Hash.h"
+#include "ota_io.h"
+#include "print_sha1.h"
+#include "unique_fd.h"
+#include "updater.h"
+
+#define BLOCKSIZE 4096
+
+// Set this to 0 to interpret 'erase' transfers to mean do a
+// BLKDISCARD ioctl (the normal behavior).  Set to 1 to interpret
+// erase to mean fill the region with zeroes.
+#define DEBUG_ERASE  0
+
+#define STASH_DIRECTORY_BASE "/cache/recovery"
+#define STASH_DIRECTORY_MODE 0700
+#define STASH_FILE_MODE 0600
+
+struct RangeSet {
+    size_t count;             // Limit is INT_MAX.
+    size_t size;
+    std::vector<size_t> pos;  // Actual limit is INT_MAX.
+};
+
+static CauseCode failure_type = kNoCause;
+static bool is_retry = false;
+static std::map<std::string, RangeSet> stash_map;
+
+static void parse_range(const std::string& range_text, RangeSet& rs) {
+
+    std::vector<std::string> pieces = android::base::Split(range_text, ",");
+    if (pieces.size() < 3) {
+        goto err;
+    }
+
+    size_t num;
+    if (!android::base::ParseUint(pieces[0].c_str(), &num, static_cast<size_t>(INT_MAX))) {
+        goto err;
+    }
+
+    if (num == 0 || num % 2) {
+        goto err; // must be even
+    } else if (num != pieces.size() - 1) {
+        goto err;
+    }
+
+    rs.pos.resize(num);
+    rs.count = num / 2;
+    rs.size = 0;
+
+    for (size_t i = 0; i < num; i += 2) {
+        if (!android::base::ParseUint(pieces[i+1].c_str(), &rs.pos[i],
+                                      static_cast<size_t>(INT_MAX))) {
+            goto err;
+        }
+
+        if (!android::base::ParseUint(pieces[i+2].c_str(), &rs.pos[i+1],
+                                      static_cast<size_t>(INT_MAX))) {
+            goto err;
+        }
+
+        if (rs.pos[i] >= rs.pos[i+1]) {
+            goto err; // empty or negative range
+        }
+
+        size_t sz = rs.pos[i+1] - rs.pos[i];
+        if (rs.size > SIZE_MAX - sz) {
+            goto err; // overflow
+        }
+
+        rs.size += sz;
+    }
+
+    return;
+
+err:
+    fprintf(stderr, "failed to parse range '%s'\n", range_text.c_str());
+    exit(1);
+}
+
+static bool range_overlaps(const RangeSet& r1, const RangeSet& r2) {
+    for (size_t i = 0; i < r1.count; ++i) {
+        size_t r1_0 = r1.pos[i * 2];
+        size_t r1_1 = r1.pos[i * 2 + 1];
+
+        for (size_t j = 0; j < r2.count; ++j) {
+            size_t r2_0 = r2.pos[j * 2];
+            size_t r2_1 = r2.pos[j * 2 + 1];
+
+            if (!(r2_0 >= r1_1 || r1_0 >= r2_1)) {
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+
+static int read_all(int fd, uint8_t* data, size_t size) {
+    size_t so_far = 0;
+    while (so_far < size) {
+        ssize_t r = TEMP_FAILURE_RETRY(ota_read(fd, data+so_far, size-so_far));
+        if (r == -1) {
+            failure_type = kFreadFailure;
+            fprintf(stderr, "read failed: %s\n", strerror(errno));
+            return -1;
+        }
+        so_far += r;
+    }
+    return 0;
+}
+
+static int read_all(int fd, std::vector<uint8_t>& buffer, size_t size) {
+    return read_all(fd, buffer.data(), size);
+}
+
+static int write_all(int fd, const uint8_t* data, size_t size) {
+    size_t written = 0;
+    while (written < size) {
+        ssize_t w = TEMP_FAILURE_RETRY(ota_write(fd, data+written, size-written));
+        if (w == -1) {
+            failure_type = kFwriteFailure;
+            fprintf(stderr, "write failed: %s\n", strerror(errno));
+            return -1;
+        }
+        written += w;
+    }
+
+    return 0;
+}
+
+static int write_all(int fd, const std::vector<uint8_t>& buffer, size_t size) {
+    return write_all(fd, buffer.data(), size);
+}
+
+static bool discard_blocks(int fd, off64_t offset, uint64_t size) {
+    // Don't discard blocks unless the update is a retry run.
+    if (!is_retry) {
+        return true;
+    }
+
+    uint64_t args[2] = {static_cast<uint64_t>(offset), size};
+    int status = ioctl(fd, BLKDISCARD, &args);
+    if (status == -1) {
+        fprintf(stderr, "BLKDISCARD ioctl failed: %s\n", strerror(errno));
+        return false;
+    }
+    return true;
+}
+
+static bool check_lseek(int fd, off64_t offset, int whence) {
+    off64_t rc = TEMP_FAILURE_RETRY(lseek64(fd, offset, whence));
+    if (rc == -1) {
+        failure_type = kLseekFailure;
+        fprintf(stderr, "lseek64 failed: %s\n", strerror(errno));
+        return false;
+    }
+    return true;
+}
+
+static void allocate(size_t size, std::vector<uint8_t>& buffer) {
+    // if the buffer's big enough, reuse it.
+    if (size <= buffer.size()) return;
+
+    buffer.resize(size);
+}
+
+struct RangeSinkState {
+    RangeSinkState(RangeSet& rs) : tgt(rs) { };
+
+    int fd;
+    const RangeSet& tgt;
+    size_t p_block;
+    size_t p_remain;
+};
+
+static ssize_t RangeSinkWrite(const uint8_t* data, ssize_t size, void* token) {
+    RangeSinkState* rss = reinterpret_cast<RangeSinkState*>(token);
+
+    if (rss->p_remain == 0) {
+        fprintf(stderr, "range sink write overrun");
+        return 0;
+    }
+
+    ssize_t written = 0;
+    while (size > 0) {
+        size_t write_now = size;
+
+        if (rss->p_remain < write_now) {
+            write_now = rss->p_remain;
+        }
+
+        if (write_all(rss->fd, data, write_now) == -1) {
+            break;
+        }
+
+        data += write_now;
+        size -= write_now;
+
+        rss->p_remain -= write_now;
+        written += write_now;
+
+        if (rss->p_remain == 0) {
+            // move to the next block
+            ++rss->p_block;
+            if (rss->p_block < rss->tgt.count) {
+                rss->p_remain = (rss->tgt.pos[rss->p_block * 2 + 1] -
+                                 rss->tgt.pos[rss->p_block * 2]) * BLOCKSIZE;
+
+                off64_t offset = static_cast<off64_t>(rss->tgt.pos[rss->p_block*2]) * BLOCKSIZE;
+                if (!discard_blocks(rss->fd, offset, rss->p_remain)) {
+                    break;
+                }
+
+                if (!check_lseek(rss->fd, offset, SEEK_SET)) {
+                    break;
+                }
+
+            } else {
+                // we can't write any more; return how many bytes have
+                // been written so far.
+                break;
+            }
+        }
+    }
+
+    return written;
+}
+
+// All of the data for all the 'new' transfers is contained in one
+// file in the update package, concatenated together in the order in
+// which transfers.list will need it.  We want to stream it out of the
+// archive (it's compressed) without writing it to a temp file, but we
+// can't write each section until it's that transfer's turn to go.
+//
+// To achieve this, we expand the new data from the archive in a
+// background thread, and block that threads 'receive uncompressed
+// data' function until the main thread has reached a point where we
+// want some new data to be written.  We signal the background thread
+// with the destination for the data and block the main thread,
+// waiting for the background thread to complete writing that section.
+// Then it signals the main thread to wake up and goes back to
+// blocking waiting for a transfer.
+//
+// NewThreadInfo is the struct used to pass information back and forth
+// between the two threads.  When the main thread wants some data
+// written, it sets rss to the destination location and signals the
+// condition.  When the background thread is done writing, it clears
+// rss and signals the condition again.
+
+struct NewThreadInfo {
+    ZipArchive* za;
+    const ZipEntry* entry;
+
+    RangeSinkState* rss;
+
+    pthread_mutex_t mu;
+    pthread_cond_t cv;
+};
+
+static bool receive_new_data(const unsigned char* data, int size, void* cookie) {
+    NewThreadInfo* nti = reinterpret_cast<NewThreadInfo*>(cookie);
+
+    while (size > 0) {
+        // Wait for nti->rss to be non-null, indicating some of this
+        // data is wanted.
+        pthread_mutex_lock(&nti->mu);
+        while (nti->rss == nullptr) {
+            pthread_cond_wait(&nti->cv, &nti->mu);
+        }
+        pthread_mutex_unlock(&nti->mu);
+
+        // At this point nti->rss is set, and we own it.  The main
+        // thread is waiting for it to disappear from nti.
+        ssize_t written = RangeSinkWrite(data, size, nti->rss);
+        data += written;
+        size -= written;
+
+        if (nti->rss->p_block == nti->rss->tgt.count) {
+            // we have written all the bytes desired by this rss.
+
+            pthread_mutex_lock(&nti->mu);
+            nti->rss = nullptr;
+            pthread_cond_broadcast(&nti->cv);
+            pthread_mutex_unlock(&nti->mu);
+        }
+    }
+
+    return true;
+}
+
+static void* unzip_new_data(void* cookie) {
+    NewThreadInfo* nti = (NewThreadInfo*) cookie;
+    mzProcessZipEntryContents(nti->za, nti->entry, receive_new_data, nti);
+    return nullptr;
+}
+
+static int ReadBlocks(const RangeSet& src, std::vector<uint8_t>& buffer, int fd) {
+    size_t p = 0;
+    uint8_t* data = buffer.data();
+
+    for (size_t i = 0; i < src.count; ++i) {
+        if (!check_lseek(fd, (off64_t) src.pos[i * 2] * BLOCKSIZE, SEEK_SET)) {
+            return -1;
+        }
+
+        size_t size = (src.pos[i * 2 + 1] - src.pos[i * 2]) * BLOCKSIZE;
+
+        if (read_all(fd, data + p, size) == -1) {
+            return -1;
+        }
+
+        p += size;
+    }
+
+    return 0;
+}
+
+static int WriteBlocks(const RangeSet& tgt, const std::vector<uint8_t>& buffer, int fd) {
+    const uint8_t* data = buffer.data();
+
+    size_t p = 0;
+    for (size_t i = 0; i < tgt.count; ++i) {
+        off64_t offset = static_cast<off64_t>(tgt.pos[i * 2]) * BLOCKSIZE;
+        size_t size = (tgt.pos[i * 2 + 1] - tgt.pos[i * 2]) * BLOCKSIZE;
+        if (!discard_blocks(fd, offset, size)) {
+            return -1;
+        }
+
+        if (!check_lseek(fd, offset, SEEK_SET)) {
+            return -1;
+        }
+
+        if (write_all(fd, data + p, size) == -1) {
+            return -1;
+        }
+
+        p += size;
+    }
+
+    return 0;
+}
+
+// Parameters for transfer list command functions
+struct CommandParameters {
+    std::vector<std::string> tokens;
+    size_t cpos;
+    const char* cmdname;
+    const char* cmdline;
+    std::string freestash;
+    std::string stashbase;
+    bool canwrite;
+    int createdstash;
+    int fd;
+    bool foundwrites;
+    bool isunresumable;
+    int version;
+    size_t written;
+    size_t stashed;
+    NewThreadInfo nti;
+    pthread_t thread;
+    std::vector<uint8_t> buffer;
+    uint8_t* patch_start;
+};
+
+// Do a source/target load for move/bsdiff/imgdiff in version 1.
+// We expect to parse the remainder of the parameter tokens as:
+//
+//    <src_range> <tgt_range>
+//
+// The source range is loaded into the provided buffer, reallocating
+// it to make it larger if necessary.
+
+static int LoadSrcTgtVersion1(CommandParameters& params, RangeSet& tgt, size_t& src_blocks,
+        std::vector<uint8_t>& buffer, int fd) {
+
+    if (params.cpos + 1 >= params.tokens.size()) {
+        fprintf(stderr, "invalid parameters\n");
+        return -1;
+    }
+
+    // <src_range>
+    RangeSet src;
+    parse_range(params.tokens[params.cpos++], src);
+
+    // <tgt_range>
+    parse_range(params.tokens[params.cpos++], tgt);
+
+    allocate(src.size * BLOCKSIZE, buffer);
+    int rc = ReadBlocks(src, buffer, fd);
+    src_blocks = src.size;
+
+    return rc;
+}
+
+static int VerifyBlocks(const std::string& expected, const std::vector<uint8_t>& buffer,
+        const size_t blocks, bool printerror) {
+    uint8_t digest[SHA_DIGEST_LENGTH];
+    const uint8_t* data = buffer.data();
+
+    SHA1(data, blocks * BLOCKSIZE, digest);
+
+    std::string hexdigest = print_sha1(digest);
+
+    if (hexdigest != expected) {
+        if (printerror) {
+            fprintf(stderr, "failed to verify blocks (expected %s, read %s)\n",
+                    expected.c_str(), hexdigest.c_str());
+        }
+        return -1;
+    }
+
+    return 0;
+}
+
+static std::string GetStashFileName(const std::string& base, const std::string& id,
+        const std::string& postfix) {
+    if (base.empty()) {
+        return "";
+    }
+
+    std::string fn(STASH_DIRECTORY_BASE);
+    fn += "/" + base + "/" + id + postfix;
+
+    return fn;
+}
+
+typedef void (*StashCallback)(const std::string&, void*);
+
+// Does a best effort enumeration of stash files. Ignores possible non-file
+// items in the stash directory and continues despite of errors. Calls the
+// 'callback' function for each file and passes 'data' to the function as a
+// parameter.
+
+static void EnumerateStash(const std::string& dirname, StashCallback callback, void* data) {
+    if (dirname.empty() || callback == nullptr) {
+        return;
+    }
+
+    std::unique_ptr<DIR, int(*)(DIR*)> directory(opendir(dirname.c_str()), closedir);
+
+    if (directory == nullptr) {
+        if (errno != ENOENT) {
+            fprintf(stderr, "opendir \"%s\" failed: %s\n", dirname.c_str(), strerror(errno));
+        }
+        return;
+    }
+
+    struct dirent* item;
+    while ((item = readdir(directory.get())) != nullptr) {
+        if (item->d_type != DT_REG) {
+            continue;
+        }
+
+        std::string fn = dirname + "/" + std::string(item->d_name);
+        callback(fn, data);
+    }
+}
+
+static void UpdateFileSize(const std::string& fn, void* data) {
+    if (fn.empty() || !data) {
+        return;
+    }
+
+    struct stat sb;
+    if (stat(fn.c_str(), &sb) == -1) {
+        fprintf(stderr, "stat \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        return;
+    }
+
+    int* size = reinterpret_cast<int*>(data);
+    *size += sb.st_size;
+}
+
+// Deletes the stash directory and all files in it. Assumes that it only
+// contains files. There is nothing we can do about unlikely, but possible
+// errors, so they are merely logged.
+
+static void DeleteFile(const std::string& fn, void* /* data */) {
+    if (!fn.empty()) {
+        fprintf(stderr, "deleting %s\n", fn.c_str());
+
+        if (unlink(fn.c_str()) == -1 && errno != ENOENT) {
+            fprintf(stderr, "unlink \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        }
+    }
+}
+
+static void DeletePartial(const std::string& fn, void* data) {
+    if (android::base::EndsWith(fn, ".partial")) {
+        DeleteFile(fn, data);
+    }
+}
+
+static void DeleteStash(const std::string& base) {
+    if (base.empty()) {
+        return;
+    }
+
+    fprintf(stderr, "deleting stash %s\n", base.c_str());
+
+    std::string dirname = GetStashFileName(base, "", "");
+    EnumerateStash(dirname, DeleteFile, nullptr);
+
+    if (rmdir(dirname.c_str()) == -1) {
+        if (errno != ENOENT && errno != ENOTDIR) {
+            fprintf(stderr, "rmdir \"%s\" failed: %s\n", dirname.c_str(), strerror(errno));
+        }
+    }
+}
+
+static int LoadStash(CommandParameters& params, const std::string& base, const std::string& id,
+        bool verify, size_t* blocks, std::vector<uint8_t>& buffer, bool printnoent) {
+    // In verify mode, if source range_set was saved for the given hash,
+    // check contents in the source blocks first. If the check fails,
+    // search for the stashed files on /cache as usual.
+    if (!params.canwrite) {
+        if (stash_map.find(id) != stash_map.end()) {
+            const RangeSet& src = stash_map[id];
+            allocate(src.size * BLOCKSIZE, buffer);
+
+            if (ReadBlocks(src, buffer, params.fd) == -1) {
+                fprintf(stderr, "failed to read source blocks in stash map.\n");
+                return -1;
+            }
+            if (VerifyBlocks(id, buffer, src.size, true) != 0) {
+                fprintf(stderr, "failed to verify loaded source blocks in stash map.\n");
+                return -1;
+            }
+            return 0;
+        }
+    }
+
+    if (base.empty()) {
+        return -1;
+    }
+
+    size_t blockcount = 0;
+
+    if (!blocks) {
+        blocks = &blockcount;
+    }
+
+    std::string fn = GetStashFileName(base, id, "");
+
+    struct stat sb;
+    int res = stat(fn.c_str(), &sb);
+
+    if (res == -1) {
+        if (errno != ENOENT || printnoent) {
+            fprintf(stderr, "stat \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        }
+        return -1;
+    }
+
+    fprintf(stderr, " loading %s\n", fn.c_str());
+
+    if ((sb.st_size % BLOCKSIZE) != 0) {
+        fprintf(stderr, "%s size %" PRId64 " not multiple of block size %d",
+                fn.c_str(), static_cast<int64_t>(sb.st_size), BLOCKSIZE);
+        return -1;
+    }
+
+    int fd = TEMP_FAILURE_RETRY(open(fn.c_str(), O_RDONLY));
+    unique_fd fd_holder(fd);
+
+    if (fd == -1) {
+        fprintf(stderr, "open \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        return -1;
+    }
+
+    allocate(sb.st_size, buffer);
+
+    if (read_all(fd, buffer, sb.st_size) == -1) {
+        return -1;
+    }
+
+    *blocks = sb.st_size / BLOCKSIZE;
+
+    if (verify && VerifyBlocks(id, buffer, *blocks, true) != 0) {
+        fprintf(stderr, "unexpected contents in %s\n", fn.c_str());
+        DeleteFile(fn, nullptr);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int WriteStash(const std::string& base, const std::string& id, int blocks,
+        std::vector<uint8_t>& buffer, bool checkspace, bool *exists) {
+    if (base.empty()) {
+        return -1;
+    }
+
+    if (checkspace && CacheSizeCheck(blocks * BLOCKSIZE) != 0) {
+        fprintf(stderr, "not enough space to write stash\n");
+        return -1;
+    }
+
+    std::string fn = GetStashFileName(base, id, ".partial");
+    std::string cn = GetStashFileName(base, id, "");
+
+    if (exists) {
+        struct stat sb;
+        int res = stat(cn.c_str(), &sb);
+
+        if (res == 0) {
+            // The file already exists and since the name is the hash of the contents,
+            // it's safe to assume the contents are identical (accidental hash collisions
+            // are unlikely)
+            fprintf(stderr, " skipping %d existing blocks in %s\n", blocks, cn.c_str());
+            *exists = true;
+            return 0;
+        }
+
+        *exists = false;
+    }
+
+    fprintf(stderr, " writing %d blocks to %s\n", blocks, cn.c_str());
+
+    int fd = TEMP_FAILURE_RETRY(open(fn.c_str(), O_WRONLY | O_CREAT | O_TRUNC, STASH_FILE_MODE));
+    unique_fd fd_holder(fd);
+
+    if (fd == -1) {
+        fprintf(stderr, "failed to create \"%s\": %s\n", fn.c_str(), strerror(errno));
+        return -1;
+    }
+
+    if (write_all(fd, buffer, blocks * BLOCKSIZE) == -1) {
+        return -1;
+    }
+
+    if (ota_fsync(fd) == -1) {
+        failure_type = kFsyncFailure;
+        fprintf(stderr, "fsync \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        return -1;
+    }
+
+    if (rename(fn.c_str(), cn.c_str()) == -1) {
+        fprintf(stderr, "rename(\"%s\", \"%s\") failed: %s\n", fn.c_str(), cn.c_str(),
+                strerror(errno));
+        return -1;
+    }
+
+    std::string dname = GetStashFileName(base, "", "");
+    int dfd = TEMP_FAILURE_RETRY(open(dname.c_str(), O_RDONLY | O_DIRECTORY));
+    unique_fd dfd_holder(dfd);
+
+    if (dfd == -1) {
+        failure_type = kFileOpenFailure;
+        fprintf(stderr, "failed to open \"%s\" failed: %s\n", dname.c_str(), strerror(errno));
+        return -1;
+    }
+
+    if (ota_fsync(dfd) == -1) {
+        failure_type = kFsyncFailure;
+        fprintf(stderr, "fsync \"%s\" failed: %s\n", dname.c_str(), strerror(errno));
+        return -1;
+    }
+
+    return 0;
+}
+
+// Creates a directory for storing stash files and checks if the /cache partition
+// hash enough space for the expected amount of blocks we need to store. Returns
+// >0 if we created the directory, zero if it existed already, and <0 of failure.
+
+static int CreateStash(State* state, int maxblocks, const char* blockdev, std::string& base) {
+    if (blockdev == nullptr) {
+        return -1;
+    }
+
+    // Stash directory should be different for each partition to avoid conflicts
+    // when updating multiple partitions at the same time, so we use the hash of
+    // the block device name as the base directory
+    uint8_t digest[SHA_DIGEST_LENGTH];
+    SHA1(reinterpret_cast<const uint8_t*>(blockdev), strlen(blockdev), digest);
+    base = print_sha1(digest);
+
+    std::string dirname = GetStashFileName(base, "", "");
+    struct stat sb;
+    int res = stat(dirname.c_str(), &sb);
+
+    if (res == -1 && errno != ENOENT) {
+        ErrorAbort(state, kStashCreationFailure, "stat \"%s\" failed: %s\n",
+                   dirname.c_str(), strerror(errno));
+        return -1;
+    } else if (res != 0) {
+        fprintf(stderr, "creating stash %s\n", dirname.c_str());
+        res = mkdir(dirname.c_str(), STASH_DIRECTORY_MODE);
+
+        if (res != 0) {
+            ErrorAbort(state, kStashCreationFailure, "mkdir \"%s\" failed: %s\n",
+                       dirname.c_str(), strerror(errno));
+            return -1;
+        }
+
+        if (CacheSizeCheck(maxblocks * BLOCKSIZE) != 0) {
+            ErrorAbort(state, kStashCreationFailure, "not enough space for stash\n");
+            return -1;
+        }
+
+        return 1;  // Created directory
+    }
+
+    fprintf(stderr, "using existing stash %s\n", dirname.c_str());
+
+    // If the directory already exists, calculate the space already allocated to
+    // stash files and check if there's enough for all required blocks. Delete any
+    // partially completed stash files first.
+
+    EnumerateStash(dirname, DeletePartial, nullptr);
+    int size = 0;
+    EnumerateStash(dirname, UpdateFileSize, &size);
+
+    size = maxblocks * BLOCKSIZE - size;
+
+    if (size > 0 && CacheSizeCheck(size) != 0) {
+        ErrorAbort(state, kStashCreationFailure, "not enough space for stash (%d more needed)\n",
+                   size);
+        return -1;
+    }
+
+    return 0; // Using existing directory
+}
+
+static int SaveStash(CommandParameters& params, const std::string& base,
+        std::vector<uint8_t>& buffer, int fd, bool usehash) {
+
+    // <stash_id> <src_range>
+    if (params.cpos + 1 >= params.tokens.size()) {
+        fprintf(stderr, "missing id and/or src range fields in stash command\n");
+        return -1;
+    }
+    const std::string& id = params.tokens[params.cpos++];
+
+    size_t blocks = 0;
+    if (usehash && LoadStash(params, base, id, true, &blocks, buffer, false) == 0) {
+        // Stash file already exists and has expected contents. Do not
+        // read from source again, as the source may have been already
+        // overwritten during a previous attempt.
+        return 0;
+    }
+
+    RangeSet src;
+    parse_range(params.tokens[params.cpos++], src);
+
+    allocate(src.size * BLOCKSIZE, buffer);
+    if (ReadBlocks(src, buffer, fd) == -1) {
+        return -1;
+    }
+    blocks = src.size;
+
+    if (usehash && VerifyBlocks(id, buffer, blocks, true) != 0) {
+        // Source blocks have unexpected contents. If we actually need this
+        // data later, this is an unrecoverable error. However, the command
+        // that uses the data may have already completed previously, so the
+        // possible failure will occur during source block verification.
+        fprintf(stderr, "failed to load source blocks for stash %s\n", id.c_str());
+        return 0;
+    }
+
+    // In verify mode, save source range_set instead of stashing blocks.
+    if (!params.canwrite && usehash) {
+        stash_map[id] = src;
+        return 0;
+    }
+
+    fprintf(stderr, "stashing %zu blocks to %s\n", blocks, id.c_str());
+    params.stashed += blocks;
+    return WriteStash(base, id, blocks, buffer, false, nullptr);
+}
+
+static int FreeStash(const std::string& base, const std::string& id) {
+    if (base.empty() || id.empty()) {
+        return -1;
+    }
+
+    std::string fn = GetStashFileName(base, id, "");
+    DeleteFile(fn, nullptr);
+
+    return 0;
+}
+
+static void MoveRange(std::vector<uint8_t>& dest, const RangeSet& locs,
+        const std::vector<uint8_t>& source) {
+    // source contains packed data, which we want to move to the
+    // locations given in locs in the dest buffer.  source and dest
+    // may be the same buffer.
+
+    const uint8_t* from = source.data();
+    uint8_t* to = dest.data();
+    size_t start = locs.size;
+    for (int i = locs.count-1; i >= 0; --i) {
+        size_t blocks = locs.pos[i*2+1] - locs.pos[i*2];
+        start -= blocks;
+        memmove(to + (locs.pos[i*2] * BLOCKSIZE), from + (start * BLOCKSIZE),
+                blocks * BLOCKSIZE);
+    }
+}
+
+// Do a source/target load for move/bsdiff/imgdiff in version 2.
+// We expect to parse the remainder of the parameter tokens as one of:
+//
+//    <tgt_range> <src_block_count> <src_range>
+//        (loads data from source image only)
+//
+//    <tgt_range> <src_block_count> - <[stash_id:stash_range] ...>
+//        (loads data from stashes only)
+//
+//    <tgt_range> <src_block_count> <src_range> <src_loc> <[stash_id:stash_range] ...>
+//        (loads data from both source image and stashes)
+//
+// On return, buffer is filled with the loaded source data (rearranged
+// and combined with stashed data as necessary).  buffer may be
+// reallocated if needed to accommodate the source data.  *tgt is the
+// target RangeSet.  Any stashes required are loaded using LoadStash.
+
+static int LoadSrcTgtVersion2(CommandParameters& params, RangeSet& tgt, size_t& src_blocks,
+        std::vector<uint8_t>& buffer, int fd, const std::string& stashbase, bool* overlap) {
+
+    // At least it needs to provide three parameters: <tgt_range>,
+    // <src_block_count> and "-"/<src_range>.
+    if (params.cpos + 2 >= params.tokens.size()) {
+        fprintf(stderr, "invalid parameters\n");
+        return -1;
+    }
+
+    // <tgt_range>
+    parse_range(params.tokens[params.cpos++], tgt);
+
+    // <src_block_count>
+    const std::string& token = params.tokens[params.cpos++];
+    if (!android::base::ParseUint(token.c_str(), &src_blocks)) {
+        fprintf(stderr, "invalid src_block_count \"%s\"\n", token.c_str());
+        return -1;
+    }
+
+    allocate(src_blocks * BLOCKSIZE, buffer);
+
+    // "-" or <src_range> [<src_loc>]
+    if (params.tokens[params.cpos] == "-") {
+        // no source ranges, only stashes
+        params.cpos++;
+    } else {
+        RangeSet src;
+        parse_range(params.tokens[params.cpos++], src);
+        int res = ReadBlocks(src, buffer, fd);
+
+        if (overlap) {
+            *overlap = range_overlaps(src, tgt);
+        }
+
+        if (res == -1) {
+            return -1;
+        }
+
+        if (params.cpos >= params.tokens.size()) {
+            // no stashes, only source range
+            return 0;
+        }
+
+        RangeSet locs;
+        parse_range(params.tokens[params.cpos++], locs);
+        MoveRange(buffer, locs, buffer);
+    }
+
+    // <[stash_id:stash_range]>
+    while (params.cpos < params.tokens.size()) {
+        // Each word is a an index into the stash table, a colon, and
+        // then a rangeset describing where in the source block that
+        // stashed data should go.
+        std::vector<std::string> tokens = android::base::Split(params.tokens[params.cpos++], ":");
+        if (tokens.size() != 2) {
+            fprintf(stderr, "invalid parameter\n");
+            return -1;
+        }
+
+        std::vector<uint8_t> stash;
+        int res = LoadStash(params, stashbase, tokens[0], false, nullptr, stash, true);
+
+        if (res == -1) {
+            // These source blocks will fail verification if used later, but we
+            // will let the caller decide if this is a fatal failure
+            fprintf(stderr, "failed to load stash %s\n", tokens[0].c_str());
+            continue;
+        }
+
+        RangeSet locs;
+        parse_range(tokens[1], locs);
+
+        MoveRange(buffer, locs, stash);
+    }
+
+    return 0;
+}
+
+// Do a source/target load for move/bsdiff/imgdiff in version 3.
+//
+// Parameters are the same as for LoadSrcTgtVersion2, except for 'onehash', which
+// tells the function whether to expect separate source and targe block hashes, or
+// if they are both the same and only one hash should be expected, and
+// 'isunresumable', which receives a non-zero value if block verification fails in
+// a way that the update cannot be resumed anymore.
+//
+// If the function is unable to load the necessary blocks or their contents don't
+// match the hashes, the return value is -1 and the command should be aborted.
+//
+// If the return value is 1, the command has already been completed according to
+// the contents of the target blocks, and should not be performed again.
+//
+// If the return value is 0, source blocks have expected content and the command
+// can be performed.
+
+static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t& src_blocks,
+        bool onehash, bool& overlap) {
+
+    if (params.cpos >= params.tokens.size()) {
+        fprintf(stderr, "missing source hash\n");
+        return -1;
+    }
+
+    std::string srchash = params.tokens[params.cpos++];
+    std::string tgthash;
+
+    if (onehash) {
+        tgthash = srchash;
+    } else {
+        if (params.cpos >= params.tokens.size()) {
+            fprintf(stderr, "missing target hash\n");
+            return -1;
+        }
+        tgthash = params.tokens[params.cpos++];
+    }
+
+    if (LoadSrcTgtVersion2(params, tgt, src_blocks, params.buffer, params.fd, params.stashbase,
+            &overlap) == -1) {
+        return -1;
+    }
+
+    std::vector<uint8_t> tgtbuffer(tgt.size * BLOCKSIZE);
+
+    if (ReadBlocks(tgt, tgtbuffer, params.fd) == -1) {
+        return -1;
+    }
+
+    if (VerifyBlocks(tgthash, tgtbuffer, tgt.size, false) == 0) {
+        // Target blocks already have expected content, command should be skipped
+        return 1;
+    }
+
+    if (VerifyBlocks(srchash, params.buffer, src_blocks, true) == 0) {
+        // If source and target blocks overlap, stash the source blocks so we can
+        // resume from possible write errors. In verify mode, we can skip stashing
+        // because the source blocks won't be overwritten.
+        if (overlap && params.canwrite) {
+            fprintf(stderr, "stashing %zu overlapping blocks to %s\n", src_blocks,
+                    srchash.c_str());
+
+            bool stash_exists = false;
+            if (WriteStash(params.stashbase, srchash, src_blocks, params.buffer, true,
+                           &stash_exists) != 0) {
+                fprintf(stderr, "failed to stash overlapping source blocks\n");
+                return -1;
+            }
+
+            params.stashed += src_blocks;
+            // Can be deleted when the write has completed
+            if (!stash_exists) {
+                params.freestash = srchash;
+            }
+        }
+
+        // Source blocks have expected content, command can proceed
+        return 0;
+    }
+
+    if (overlap && LoadStash(params, params.stashbase, srchash, true, nullptr, params.buffer,
+                             true) == 0) {
+        // Overlapping source blocks were previously stashed, command can proceed.
+        // We are recovering from an interrupted command, so we don't know if the
+        // stash can safely be deleted after this command.
+        return 0;
+    }
+
+    // Valid source data not available, update cannot be resumed
+    fprintf(stderr, "partition has unexpected contents\n");
+    params.isunresumable = true;
+
+    return -1;
+}
+
+static int PerformCommandMove(CommandParameters& params) {
+    size_t blocks = 0;
+    bool overlap = false;
+    int status = 0;
+    RangeSet tgt;
+
+    if (params.version == 1) {
+        status = LoadSrcTgtVersion1(params, tgt, blocks, params.buffer, params.fd);
+    } else if (params.version == 2) {
+        status = LoadSrcTgtVersion2(params, tgt, blocks, params.buffer, params.fd,
+                params.stashbase, nullptr);
+    } else if (params.version >= 3) {
+        status = LoadSrcTgtVersion3(params, tgt, blocks, true, overlap);
+    }
+
+    if (status == -1) {
+        fprintf(stderr, "failed to read blocks for move\n");
+        return -1;
+    }
+
+    if (status == 0) {
+        params.foundwrites = true;
+    } else if (params.foundwrites) {
+        fprintf(stderr, "warning: commands executed out of order [%s]\n", params.cmdname);
+    }
+
+    if (params.canwrite) {
+        if (status == 0) {
+            fprintf(stderr, "  moving %zu blocks\n", blocks);
+
+            if (WriteBlocks(tgt, params.buffer, params.fd) == -1) {
+                return -1;
+            }
+        } else {
+            fprintf(stderr, "skipping %zu already moved blocks\n", blocks);
+        }
+
+    }
+
+    if (!params.freestash.empty()) {
+        FreeStash(params.stashbase, params.freestash);
+        params.freestash.clear();
+    }
+
+    params.written += tgt.size;
+
+    return 0;
+}
+
+static int PerformCommandStash(CommandParameters& params) {
+    return SaveStash(params, params.stashbase, params.buffer, params.fd,
+            (params.version >= 3));
+}
+
+static int PerformCommandFree(CommandParameters& params) {
+    // <stash_id>
+    if (params.cpos >= params.tokens.size()) {
+        fprintf(stderr, "missing stash id in free command\n");
+        return -1;
+    }
+
+    const std::string& id = params.tokens[params.cpos++];
+
+    if (!params.canwrite && stash_map.find(id) != stash_map.end()) {
+        stash_map.erase(id);
+        return 0;
+    }
+
+    if (params.createdstash || params.canwrite) {
+        return FreeStash(params.stashbase, id);
+    }
+
+    return 0;
+}
+
+static int PerformCommandZero(CommandParameters& params) {
+
+    if (params.cpos >= params.tokens.size()) {
+        fprintf(stderr, "missing target blocks for zero\n");
+        return -1;
+    }
+
+    RangeSet tgt;
+    parse_range(params.tokens[params.cpos++], tgt);
+
+    fprintf(stderr, "  zeroing %zu blocks\n", tgt.size);
+
+    allocate(BLOCKSIZE, params.buffer);
+    memset(params.buffer.data(), 0, BLOCKSIZE);
+
+    if (params.canwrite) {
+        for (size_t i = 0; i < tgt.count; ++i) {
+            off64_t offset = static_cast<off64_t>(tgt.pos[i * 2]) * BLOCKSIZE;
+            size_t size = (tgt.pos[i * 2 + 1] - tgt.pos[i * 2]) * BLOCKSIZE;
+            if (!discard_blocks(params.fd, offset, size)) {
+                return -1;
+            }
+
+            if (!check_lseek(params.fd, offset, SEEK_SET)) {
+                return -1;
+            }
+
+            for (size_t j = tgt.pos[i * 2]; j < tgt.pos[i * 2 + 1]; ++j) {
+                if (write_all(params.fd, params.buffer, BLOCKSIZE) == -1) {
+                    return -1;
+                }
+            }
+        }
+    }
+
+    if (params.cmdname[0] == 'z') {
+        // Update only for the zero command, as the erase command will call
+        // this if DEBUG_ERASE is defined.
+        params.written += tgt.size;
+    }
+
+    return 0;
+}
+
+static int PerformCommandNew(CommandParameters& params) {
+
+    if (params.cpos >= params.tokens.size()) {
+        fprintf(stderr, "missing target blocks for new\n");
+        return -1;
+    }
+
+    RangeSet tgt;
+    parse_range(params.tokens[params.cpos++], tgt);
+
+    if (params.canwrite) {
+        fprintf(stderr, " writing %zu blocks of new data\n", tgt.size);
+
+        RangeSinkState rss(tgt);
+        rss.fd = params.fd;
+        rss.p_block = 0;
+        rss.p_remain = (tgt.pos[1] - tgt.pos[0]) * BLOCKSIZE;
+
+        off64_t offset = static_cast<off64_t>(tgt.pos[0]) * BLOCKSIZE;
+        if (!discard_blocks(params.fd, offset, tgt.size * BLOCKSIZE)) {
+            return -1;
+        }
+
+        if (!check_lseek(params.fd, offset, SEEK_SET)) {
+            return -1;
+        }
+
+        pthread_mutex_lock(&params.nti.mu);
+        params.nti.rss = &rss;
+        pthread_cond_broadcast(&params.nti.cv);
+
+        while (params.nti.rss) {
+            pthread_cond_wait(&params.nti.cv, &params.nti.mu);
+        }
+
+        pthread_mutex_unlock(&params.nti.mu);
+    }
+
+    params.written += tgt.size;
+
+    return 0;
+}
+
+static int PerformCommandDiff(CommandParameters& params) {
+
+    // <offset> <length>
+    if (params.cpos + 1 >= params.tokens.size()) {
+        fprintf(stderr, "missing patch offset or length for %s\n", params.cmdname);
+        return -1;
+    }
+
+    size_t offset;
+    if (!android::base::ParseUint(params.tokens[params.cpos++].c_str(), &offset)) {
+        fprintf(stderr, "invalid patch offset\n");
+        return -1;
+    }
+
+    size_t len;
+    if (!android::base::ParseUint(params.tokens[params.cpos++].c_str(), &len)) {
+        fprintf(stderr, "invalid patch offset\n");
+        return -1;
+    }
+
+    RangeSet tgt;
+    size_t blocks = 0;
+    bool overlap = false;
+    int status = 0;
+    if (params.version == 1) {
+        status = LoadSrcTgtVersion1(params, tgt, blocks, params.buffer, params.fd);
+    } else if (params.version == 2) {
+        status = LoadSrcTgtVersion2(params, tgt, blocks, params.buffer, params.fd,
+                params.stashbase, nullptr);
+    } else if (params.version >= 3) {
+        status = LoadSrcTgtVersion3(params, tgt, blocks, false, overlap);
+    }
+
+    if (status == -1) {
+        fprintf(stderr, "failed to read blocks for diff\n");
+        return -1;
+    }
+
+    if (status == 0) {
+        params.foundwrites = true;
+    } else if (params.foundwrites) {
+        fprintf(stderr, "warning: commands executed out of order [%s]\n", params.cmdname);
+    }
+
+    if (params.canwrite) {
+        if (status == 0) {
+            fprintf(stderr, "patching %zu blocks to %zu\n", blocks, tgt.size);
+
+            Value patch_value;
+            patch_value.type = VAL_BLOB;
+            patch_value.size = len;
+            patch_value.data = (char*) (params.patch_start + offset);
+
+            RangeSinkState rss(tgt);
+            rss.fd = params.fd;
+            rss.p_block = 0;
+            rss.p_remain = (tgt.pos[1] - tgt.pos[0]) * BLOCKSIZE;
+
+            off64_t offset = static_cast<off64_t>(tgt.pos[0]) * BLOCKSIZE;
+            if (!discard_blocks(params.fd, offset, rss.p_remain)) {
+                return -1;
+            }
+
+            if (!check_lseek(params.fd, offset, SEEK_SET)) {
+                return -1;
+            }
+
+            if (params.cmdname[0] == 'i') {      // imgdiff
+                if (ApplyImagePatch(params.buffer.data(), blocks * BLOCKSIZE, &patch_value,
+                        &RangeSinkWrite, &rss, nullptr, nullptr) != 0) {
+                    fprintf(stderr, "Failed to apply image patch.\n");
+                    return -1;
+                }
+            } else {
+                if (ApplyBSDiffPatch(params.buffer.data(), blocks * BLOCKSIZE, &patch_value,
+                        0, &RangeSinkWrite, &rss, nullptr) != 0) {
+                    fprintf(stderr, "Failed to apply bsdiff patch.\n");
+                    return -1;
+                }
+            }
+
+            // We expect the output of the patcher to fill the tgt ranges exactly.
+            if (rss.p_block != tgt.count || rss.p_remain != 0) {
+                fprintf(stderr, "range sink underrun?\n");
+            }
+        } else {
+            fprintf(stderr, "skipping %zu blocks already patched to %zu [%s]\n",
+                blocks, tgt.size, params.cmdline);
+        }
+    }
+
+    if (!params.freestash.empty()) {
+        FreeStash(params.stashbase, params.freestash);
+        params.freestash.clear();
+    }
+
+    params.written += tgt.size;
+
+    return 0;
+}
+
+static int PerformCommandErase(CommandParameters& params) {
+    if (DEBUG_ERASE) {
+        return PerformCommandZero(params);
+    }
+
+    struct stat sb;
+    if (fstat(params.fd, &sb) == -1) {
+        fprintf(stderr, "failed to fstat device to erase: %s\n", strerror(errno));
+        return -1;
+    }
+
+    if (!S_ISBLK(sb.st_mode)) {
+        fprintf(stderr, "not a block device; skipping erase\n");
+        return -1;
+    }
+
+    if (params.cpos >= params.tokens.size()) {
+        fprintf(stderr, "missing target blocks for erase\n");
+        return -1;
+    }
+
+    RangeSet tgt;
+    parse_range(params.tokens[params.cpos++], tgt);
+
+    if (params.canwrite) {
+        fprintf(stderr, " erasing %zu blocks\n", tgt.size);
+
+        for (size_t i = 0; i < tgt.count; ++i) {
+            uint64_t blocks[2];
+            // offset in bytes
+            blocks[0] = tgt.pos[i * 2] * (uint64_t) BLOCKSIZE;
+            // length in bytes
+            blocks[1] = (tgt.pos[i * 2 + 1] - tgt.pos[i * 2]) * (uint64_t) BLOCKSIZE;
+
+            if (ioctl(params.fd, BLKDISCARD, &blocks) == -1) {
+                fprintf(stderr, "BLKDISCARD ioctl failed: %s\n", strerror(errno));
+                return -1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+// Definitions for transfer list command functions
+typedef int (*CommandFunction)(CommandParameters&);
+
+struct Command {
+    const char* name;
+    CommandFunction f;
+};
+
+// CompareCommands and CompareCommandNames are for the hash table
+
+static int CompareCommands(const void* c1, const void* c2) {
+    return strcmp(((const Command*) c1)->name, ((const Command*) c2)->name);
+}
+
+static int CompareCommandNames(const void* c1, const void* c2) {
+    return strcmp(((const Command*) c1)->name, (const char*) c2);
+}
+
+// HashString is used to hash command names for the hash table
+
+static unsigned int HashString(const char *s) {
+    unsigned int hash = 0;
+    if (s) {
+        while (*s) {
+            hash = hash * 33 + *s++;
+        }
+    }
+    return hash;
+}
+
+// args:
+//    - block device (or file) to modify in-place
+//    - transfer list (blob)
+//    - new data stream (filename within package.zip)
+//    - patch stream (filename within package.zip, must be uncompressed)
+
+static Value* PerformBlockImageUpdate(const char* name, State* state, int /* argc */, Expr* argv[],
+        const Command* commands, size_t cmdcount, bool dryrun) {
+    CommandParameters params;
+    memset(&params, 0, sizeof(params));
+    params.canwrite = !dryrun;
+
+    fprintf(stderr, "performing %s\n", dryrun ? "verification" : "update");
+    if (state->is_retry) {
+        is_retry = true;
+        fprintf(stderr, "This update is a retry.\n");
+    }
+
+    Value* blockdev_filename = nullptr;
+    Value* transfer_list_value = nullptr;
+    Value* new_data_fn = nullptr;
+    Value* patch_data_fn = nullptr;
+    if (ReadValueArgs(state, argv, 4, &blockdev_filename, &transfer_list_value,
+            &new_data_fn, &patch_data_fn) < 0) {
+        return StringValue(strdup(""));
+    }
+    std::unique_ptr<Value, decltype(&FreeValue)> blockdev_filename_holder(blockdev_filename,
+            FreeValue);
+    std::unique_ptr<Value, decltype(&FreeValue)> transfer_list_value_holder(transfer_list_value,
+            FreeValue);
+    std::unique_ptr<Value, decltype(&FreeValue)> new_data_fn_holder(new_data_fn, FreeValue);
+    std::unique_ptr<Value, decltype(&FreeValue)> patch_data_fn_holder(patch_data_fn, FreeValue);
+
+    if (blockdev_filename->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "blockdev_filename argument to %s must be string",
+                   name);
+        return StringValue(strdup(""));
+    }
+    if (transfer_list_value->type != VAL_BLOB) {
+        ErrorAbort(state, kArgsParsingFailure, "transfer_list argument to %s must be blob", name);
+        return StringValue(strdup(""));
+    }
+    if (new_data_fn->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "new_data_fn argument to %s must be string", name);
+        return StringValue(strdup(""));
+    }
+    if (patch_data_fn->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "patch_data_fn argument to %s must be string",
+                   name);
+        return StringValue(strdup(""));
+    }
+
+    UpdaterInfo* ui = reinterpret_cast<UpdaterInfo*>(state->cookie);
+
+    if (ui == nullptr) {
+        return StringValue(strdup(""));
+    }
+
+    FILE* cmd_pipe = ui->cmd_pipe;
+    ZipArchive* za = ui->package_zip;
+
+    if (cmd_pipe == nullptr || za == nullptr) {
+        return StringValue(strdup(""));
+    }
+
+    const ZipEntry* patch_entry = mzFindZipEntry(za, patch_data_fn->data);
+    if (patch_entry == nullptr) {
+        fprintf(stderr, "%s(): no file \"%s\" in package", name, patch_data_fn->data);
+        return StringValue(strdup(""));
+    }
+
+    params.patch_start = ui->package_zip_addr + mzGetZipEntryOffset(patch_entry);
+    const ZipEntry* new_entry = mzFindZipEntry(za, new_data_fn->data);
+    if (new_entry == nullptr) {
+        fprintf(stderr, "%s(): no file \"%s\" in package", name, new_data_fn->data);
+        return StringValue(strdup(""));
+    }
+
+    params.fd = TEMP_FAILURE_RETRY(open(blockdev_filename->data, O_RDWR));
+    unique_fd fd_holder(params.fd);
+
+    if (params.fd == -1) {
+        fprintf(stderr, "open \"%s\" failed: %s\n", blockdev_filename->data, strerror(errno));
+        return StringValue(strdup(""));
+    }
+
+    if (params.canwrite) {
+        params.nti.za = za;
+        params.nti.entry = new_entry;
+
+        pthread_mutex_init(&params.nti.mu, nullptr);
+        pthread_cond_init(&params.nti.cv, nullptr);
+        pthread_attr_t attr;
+        pthread_attr_init(&attr);
+        pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+
+        int error = pthread_create(&params.thread, &attr, unzip_new_data, &params.nti);
+        if (error != 0) {
+            fprintf(stderr, "pthread_create failed: %s\n", strerror(error));
+            return StringValue(strdup(""));
+        }
+    }
+
+    // Copy all the lines in transfer_list_value into std::string for
+    // processing.
+    const std::string transfer_list(transfer_list_value->data, transfer_list_value->size);
+    std::vector<std::string> lines = android::base::Split(transfer_list, "\n");
+    if (lines.size() < 2) {
+        ErrorAbort(state, kArgsParsingFailure, "too few lines in the transfer list [%zd]\n",
+                   lines.size());
+        return StringValue(strdup(""));
+    }
+
+    // First line in transfer list is the version number
+    if (!android::base::ParseInt(lines[0].c_str(), &params.version, 1, 4)) {
+        fprintf(stderr, "unexpected transfer list version [%s]\n", lines[0].c_str());
+        return StringValue(strdup(""));
+    }
+
+    fprintf(stderr, "blockimg version is %d\n", params.version);
+
+    // Second line in transfer list is the total number of blocks we expect to write
+    int total_blocks;
+    if (!android::base::ParseInt(lines[1].c_str(), &total_blocks, 0)) {
+        ErrorAbort(state, kArgsParsingFailure, "unexpected block count [%s]\n", lines[1].c_str());
+        return StringValue(strdup(""));
+    }
+
+    if (total_blocks == 0) {
+        return StringValue(strdup("t"));
+    }
+
+    size_t start = 2;
+    if (params.version >= 2) {
+        if (lines.size() < 4) {
+            ErrorAbort(state, kArgsParsingFailure, "too few lines in the transfer list [%zu]\n",
+                       lines.size());
+            return StringValue(strdup(""));
+        }
+
+        // Third line is how many stash entries are needed simultaneously
+        fprintf(stderr, "maximum stash entries %s\n", lines[2].c_str());
+
+        // Fourth line is the maximum number of blocks that will be stashed simultaneously
+        int stash_max_blocks;
+        if (!android::base::ParseInt(lines[3].c_str(), &stash_max_blocks, 0)) {
+            ErrorAbort(state, kArgsParsingFailure, "unexpected maximum stash blocks [%s]\n",
+                       lines[3].c_str());
+            return StringValue(strdup(""));
+        }
+
+        int res = CreateStash(state, stash_max_blocks, blockdev_filename->data, params.stashbase);
+        if (res == -1) {
+            return StringValue(strdup(""));
+        }
+
+        params.createdstash = res;
+
+        start += 2;
+    }
+
+    // Build a hash table of the available commands
+    HashTable* cmdht = mzHashTableCreate(cmdcount, nullptr);
+    std::unique_ptr<HashTable, decltype(&mzHashTableFree)> cmdht_holder(cmdht, mzHashTableFree);
+
+    for (size_t i = 0; i < cmdcount; ++i) {
+        unsigned int cmdhash = HashString(commands[i].name);
+        mzHashTableLookup(cmdht, cmdhash, (void*) &commands[i], CompareCommands, true);
+    }
+
+    int rc = -1;
+
+    // Subsequent lines are all individual transfer commands
+    for (auto it = lines.cbegin() + start; it != lines.cend(); it++) {
+        const std::string& line_str(*it);
+        if (line_str.empty()) {
+            continue;
+        }
+
+        params.tokens = android::base::Split(line_str, " ");
+        params.cpos = 0;
+        params.cmdname = params.tokens[params.cpos++].c_str();
+        params.cmdline = line_str.c_str();
+
+        unsigned int cmdhash = HashString(params.cmdname);
+        const Command* cmd = reinterpret_cast<const Command*>(mzHashTableLookup(cmdht, cmdhash,
+                const_cast<char*>(params.cmdname), CompareCommandNames,
+                false));
+
+        if (cmd == nullptr) {
+            fprintf(stderr, "unexpected command [%s]\n", params.cmdname);
+            goto pbiudone;
+        }
+
+        if (cmd->f != nullptr && cmd->f(params) == -1) {
+            fprintf(stderr, "failed to execute command [%s]\n", line_str.c_str());
+            goto pbiudone;
+        }
+
+        if (params.canwrite) {
+            if (ota_fsync(params.fd) == -1) {
+                failure_type = kFsyncFailure;
+                fprintf(stderr, "fsync failed: %s\n", strerror(errno));
+                goto pbiudone;
+            }
+            fprintf(cmd_pipe, "set_progress %.4f\n", (double) params.written / total_blocks);
+            fflush(cmd_pipe);
+        }
+    }
+
+    if (params.canwrite) {
+        pthread_join(params.thread, nullptr);
+
+        fprintf(stderr, "wrote %zu blocks; expected %d\n", params.written, total_blocks);
+        fprintf(stderr, "stashed %zu blocks\n", params.stashed);
+        fprintf(stderr, "max alloc needed was %zu\n", params.buffer.size());
+
+        const char* partition = strrchr(blockdev_filename->data, '/');
+        if (partition != nullptr && *(partition+1) != 0) {
+            fprintf(cmd_pipe, "log bytes_written_%s: %zu\n", partition + 1,
+                    params.written * BLOCKSIZE);
+            fprintf(cmd_pipe, "log bytes_stashed_%s: %zu\n", partition + 1,
+                    params.stashed * BLOCKSIZE);
+            fflush(cmd_pipe);
+        }
+        // Delete stash only after successfully completing the update, as it
+        // may contain blocks needed to complete the update later.
+        DeleteStash(params.stashbase);
+    } else {
+        fprintf(stderr, "verified partition contents; update may be resumed\n");
+    }
+
+    rc = 0;
+
+pbiudone:
+    if (ota_fsync(params.fd) == -1) {
+        failure_type = kFsyncFailure;
+        fprintf(stderr, "fsync failed: %s\n", strerror(errno));
+    }
+    // params.fd will be automatically closed because of the fd_holder above.
+
+    // Only delete the stash if the update cannot be resumed, or it's
+    // a verification run and we created the stash.
+    if (params.isunresumable || (!params.canwrite && params.createdstash)) {
+        DeleteStash(params.stashbase);
+    }
+
+    if (failure_type != kNoCause && state->cause_code == kNoCause) {
+        state->cause_code = failure_type;
+    }
+
+    return StringValue(rc == 0 ? strdup("t") : strdup(""));
+}
+
+// The transfer list is a text file containing commands to
+// transfer data from one place to another on the target
+// partition.  We parse it and execute the commands in order:
+//
+//    zero [rangeset]
+//      - fill the indicated blocks with zeros
+//
+//    new [rangeset]
+//      - fill the blocks with data read from the new_data file
+//
+//    erase [rangeset]
+//      - mark the given blocks as empty
+//
+//    move <...>
+//    bsdiff <patchstart> <patchlen> <...>
+//    imgdiff <patchstart> <patchlen> <...>
+//      - read the source blocks, apply a patch (or not in the
+//        case of move), write result to target blocks.  bsdiff or
+//        imgdiff specifies the type of patch; move means no patch
+//        at all.
+//
+//        The format of <...> differs between versions 1 and 2;
+//        see the LoadSrcTgtVersion{1,2}() functions for a
+//        description of what's expected.
+//
+//    stash <stash_id> <src_range>
+//      - (version 2+ only) load the given source range and stash
+//        the data in the given slot of the stash table.
+//
+//    free <stash_id>
+//      - (version 3+ only) free the given stash data.
+//
+// The creator of the transfer list will guarantee that no block
+// is read (ie, used as the source for a patch or move) after it
+// has been written.
+//
+// In version 2, the creator will guarantee that a given stash is
+// loaded (with a stash command) before it's used in a
+// move/bsdiff/imgdiff command.
+//
+// Within one command the source and target ranges may overlap so
+// in general we need to read the entire source into memory before
+// writing anything to the target blocks.
+//
+// All the patch data is concatenated into one patch_data file in
+// the update package.  It must be stored uncompressed because we
+// memory-map it in directly from the archive.  (Since patches are
+// already compressed, we lose very little by not compressing
+// their concatenation.)
+//
+// In version 3, commands that read data from the partition (i.e.
+// move/bsdiff/imgdiff/stash) have one or more additional hashes
+// before the range parameters, which are used to check if the
+// command has already been completed and verify the integrity of
+// the source data.
+
+Value* BlockImageVerifyFn(const char* name, State* state, int argc, Expr* argv[]) {
+    // Commands which are not tested are set to nullptr to skip them completely
+    const Command commands[] = {
+        { "bsdiff",     PerformCommandDiff  },
+        { "erase",      nullptr             },
+        { "free",       PerformCommandFree  },
+        { "imgdiff",    PerformCommandDiff  },
+        { "move",       PerformCommandMove  },
+        { "new",        nullptr             },
+        { "stash",      PerformCommandStash },
+        { "zero",       nullptr             }
+    };
+
+    // Perform a dry run without writing to test if an update can proceed
+    return PerformBlockImageUpdate(name, state, argc, argv, commands,
+                sizeof(commands) / sizeof(commands[0]), true);
+}
+
+Value* BlockImageUpdateFn(const char* name, State* state, int argc, Expr* argv[]) {
+    const Command commands[] = {
+        { "bsdiff",     PerformCommandDiff  },
+        { "erase",      PerformCommandErase },
+        { "free",       PerformCommandFree  },
+        { "imgdiff",    PerformCommandDiff  },
+        { "move",       PerformCommandMove  },
+        { "new",        PerformCommandNew   },
+        { "stash",      PerformCommandStash },
+        { "zero",       PerformCommandZero  }
+    };
+
+    return PerformBlockImageUpdate(name, state, argc, argv, commands,
+                sizeof(commands) / sizeof(commands[0]), false);
+}
+
+Value* RangeSha1Fn(const char* name, State* state, int /* argc */, Expr* argv[]) {
+    Value* blockdev_filename;
+    Value* ranges;
+
+    if (ReadValueArgs(state, argv, 2, &blockdev_filename, &ranges) < 0) {
+        return StringValue(strdup(""));
+    }
+    std::unique_ptr<Value, decltype(&FreeValue)> ranges_holder(ranges, FreeValue);
+    std::unique_ptr<Value, decltype(&FreeValue)> blockdev_filename_holder(blockdev_filename,
+            FreeValue);
+
+    if (blockdev_filename->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "blockdev_filename argument to %s must be string",
+                   name);
+        return StringValue(strdup(""));
+    }
+    if (ranges->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "ranges argument to %s must be string", name);
+        return StringValue(strdup(""));
+    }
+
+    int fd = open(blockdev_filename->data, O_RDWR);
+    unique_fd fd_holder(fd);
+    if (fd < 0) {
+        ErrorAbort(state, kFileOpenFailure, "open \"%s\" failed: %s", blockdev_filename->data,
+                   strerror(errno));
+        return StringValue(strdup(""));
+    }
+
+    RangeSet rs;
+    parse_range(ranges->data, rs);
+
+    SHA_CTX ctx;
+    SHA1_Init(&ctx);
+
+    std::vector<uint8_t> buffer(BLOCKSIZE);
+    for (size_t i = 0; i < rs.count; ++i) {
+        if (!check_lseek(fd, (off64_t)rs.pos[i*2] * BLOCKSIZE, SEEK_SET)) {
+            ErrorAbort(state, kLseekFailure, "failed to seek %s: %s", blockdev_filename->data,
+                       strerror(errno));
+            return StringValue(strdup(""));
+        }
+
+        for (size_t j = rs.pos[i*2]; j < rs.pos[i*2+1]; ++j) {
+            if (read_all(fd, buffer, BLOCKSIZE) == -1) {
+                ErrorAbort(state, kFreadFailure, "failed to read %s: %s", blockdev_filename->data,
+                        strerror(errno));
+                return StringValue(strdup(""));
+            }
+
+            SHA1_Update(&ctx, buffer.data(), BLOCKSIZE);
+        }
+    }
+    uint8_t digest[SHA_DIGEST_LENGTH];
+    SHA1_Final(digest, &ctx);
+
+    return StringValue(strdup(print_sha1(digest).c_str()));
+}
+
+// This function checks if a device has been remounted R/W prior to an incremental
+// OTA update. This is an common cause of update abortion. The function reads the
+// 1st block of each partition and check for mounting time/count. It return string "t"
+// if executes successfully and an empty string otherwise.
+
+Value* CheckFirstBlockFn(const char* name, State* state, int argc, Expr* argv[]) {
+    Value* arg_filename;
+
+    if (ReadValueArgs(state, argv, 1, &arg_filename) < 0) {
+        return nullptr;
+    }
+    std::unique_ptr<Value, decltype(&FreeValue)> filename(arg_filename, FreeValue);
+
+    if (filename->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "filename argument to %s must be string", name);
+        return StringValue(strdup(""));
+    }
+
+    int fd = open(arg_filename->data, O_RDONLY);
+    unique_fd fd_holder(fd);
+    if (fd == -1) {
+        ErrorAbort(state, kFileOpenFailure, "open \"%s\" failed: %s", arg_filename->data,
+                   strerror(errno));
+        return StringValue(strdup(""));
+    }
+
+    RangeSet blk0 {1 /*count*/, 1/*size*/, std::vector<size_t> {0, 1}/*position*/};
+    std::vector<uint8_t> block0_buffer(BLOCKSIZE);
+
+    if (ReadBlocks(blk0, block0_buffer, fd) == -1) {
+        ErrorAbort(state, kFreadFailure, "failed to read %s: %s", arg_filename->data,
+                strerror(errno));
+        return StringValue(strdup(""));
+    }
+
+    // https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout
+    // Super block starts from block 0, offset 0x400
+    //   0x2C: len32 Mount time
+    //   0x30: len32 Write time
+    //   0x34: len16 Number of mounts since the last fsck
+    //   0x38: len16 Magic signature 0xEF53
+
+    time_t mount_time = *reinterpret_cast<uint32_t*>(&block0_buffer[0x400+0x2C]);
+    uint16_t mount_count = *reinterpret_cast<uint16_t*>(&block0_buffer[0x400+0x34]);
+
+    if (mount_count > 0) {
+        uiPrintf(state, "Device was remounted R/W %d times\n", mount_count);
+        uiPrintf(state, "Last remount happened on %s", ctime(&mount_time));
+    }
+
+    return StringValue(strdup("t"));
+}
+
+
+Value* BlockImageRecoverFn(const char* name, State* state, int argc, Expr* argv[]) {
+    Value* arg_filename;
+    Value* arg_ranges;
+
+    if (ReadValueArgs(state, argv, 2, &arg_filename, &arg_ranges) < 0) {
+        return NULL;
+    }
+
+    std::unique_ptr<Value, decltype(&FreeValue)> filename(arg_filename, FreeValue);
+    std::unique_ptr<Value, decltype(&FreeValue)> ranges(arg_ranges, FreeValue);
+
+    if (filename->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "filename argument to %s must be string", name);
+        return StringValue(strdup(""));
+    }
+    if (ranges->type != VAL_STRING) {
+        ErrorAbort(state, kArgsParsingFailure, "ranges argument to %s must be string", name);
+        return StringValue(strdup(""));
+    }
+
+    // Output notice to log when recover is attempted
+    fprintf(stderr, "%s image corrupted, attempting to recover...\n", filename->data);
+
+    // When opened with O_RDWR, libfec rewrites corrupted blocks when they are read
+    fec::io fh(filename->data, O_RDWR);
+
+    if (!fh) {
+        ErrorAbort(state, kLibfecFailure, "fec_open \"%s\" failed: %s", filename->data,
+                   strerror(errno));
+        return StringValue(strdup(""));
+    }
+
+    if (!fh.has_ecc() || !fh.has_verity()) {
+        ErrorAbort(state, kLibfecFailure, "unable to use metadata to correct errors");
+        return StringValue(strdup(""));
+    }
+
+    fec_status status;
+
+    if (!fh.get_status(status)) {
+        ErrorAbort(state, kLibfecFailure, "failed to read FEC status");
+        return StringValue(strdup(""));
+    }
+
+    RangeSet rs;
+    parse_range(ranges->data, rs);
+
+    uint8_t buffer[BLOCKSIZE];
+
+    for (size_t i = 0; i < rs.count; ++i) {
+        for (size_t j = rs.pos[i * 2]; j < rs.pos[i * 2 + 1]; ++j) {
+            // Stay within the data area, libfec validates and corrects metadata
+            if (status.data_size <= (uint64_t)j * BLOCKSIZE) {
+                continue;
+            }
+
+            if (fh.pread(buffer, BLOCKSIZE, (off64_t)j * BLOCKSIZE) != BLOCKSIZE) {
+                ErrorAbort(state, kLibfecFailure, "failed to recover %s (block %zu): %s",
+                           filename->data, j, strerror(errno));
+                return StringValue(strdup(""));
+            }
+
+            // If we want to be able to recover from a situation where rewriting a corrected
+            // block doesn't guarantee the same data will be returned when re-read later, we
+            // can save a copy of corrected blocks to /cache. Note:
+            //
+            //  1. Maximum space required from /cache is the same as the maximum number of
+            //     corrupted blocks we can correct. For RS(255, 253) and a 2 GiB partition,
+            //     this would be ~16 MiB, for example.
+            //
+            //  2. To find out if this block was corrupted, call fec_get_status after each
+            //     read and check if the errors field value has increased.
+        }
+    }
+    fprintf(stderr, "...%s image recovered successfully.\n", filename->data);
+    return StringValue(strdup("t"));
+}
+
+void RegisterBlockImageFunctions() {
+    RegisterFunction("block_image_verify", BlockImageVerifyFn);
+    RegisterFunction("block_image_update", BlockImageUpdateFn);
+    RegisterFunction("block_image_recover", BlockImageRecoverFn);
+    RegisterFunction("check_first_block", CheckFirstBlockFn);
+    RegisterFunction("range_sha1", RangeSha1Fn);
+}
diff --git a/updater/install.c b/updater/install.cpp
index d0e7d1aef..88f771471 100644
--- a/updater/install.c
+++ b/updater/install.cpp
@@ -34,16 +34,25 @@
 #include <linux/xattr.h>
 #include <inttypes.h>
 
+#include <memory>
+#include <vector>
+
+#include <android-base/parseint.h>
+#include <android-base/strings.h>
+#include <android-base/stringprintf.h>
+
 #include "bootloader.h"
 #include "applypatch/applypatch.h"
 #include "cutils/android_reboot.h"
 #include "cutils/misc.h"
 #include "cutils/properties.h"
 #include "edify/expr.h"
-#include "mincrypt/sha.h"
+#include "error_code.h"
 #include "minzip/DirUtil.h"
 #include "mtdutils/mounts.h"
 #include "mtdutils/mtdutils.h"
+#include "openssl/sha.h"
+#include "ota_io.h"
 #include "updater.h"
 #include "applypatch/applypatch.h"
 #include "flashutils/flashutils.h"
@@ -57,32 +66,44 @@
 #include "wipe.h"
 #endif
 
-void uiPrint(State* state, char* buffer) {
-    char* line = strtok(buffer, "\n");
-    UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
-    while (line) {
-        fprintf(ui->cmd_pipe, "ui_print %s\n", line);
-        line = strtok(NULL, "\n");
+// Send over the buffer to recovery though the command pipe.
+static void uiPrint(State* state, const std::string& buffer) {
+    UpdaterInfo* ui = reinterpret_cast<UpdaterInfo*>(state->cookie);
+
+    // "line1\nline2\n" will be split into 3 tokens: "line1", "line2" and "".
+    // So skip sending empty strings to UI.
+    std::vector<std::string> lines = android::base::Split(buffer, "\n");
+    for (auto& line: lines) {
+        if (!line.empty()) {
+            fprintf(ui->cmd_pipe, "ui_print %s\n", line.c_str());
+            fprintf(ui->cmd_pipe, "ui_print\n");
+        }
     }
-    fprintf(ui->cmd_pipe, "ui_print\n");
+
+    // On the updater side, we need to dump the contents to stderr (which has
+    // been redirected to the log file). Because the recovery will only print
+    // the contents to screen when processing pipe command ui_print.
+    fprintf(stderr, "%s", buffer.c_str());
 }
 
 __attribute__((__format__(printf, 2, 3))) __nonnull((2))
 void uiPrintf(State* state, const char* format, ...) {
-    char error_msg[1024];
+    std::string error_msg;
+
     va_list ap;
     va_start(ap, format);
-    vsnprintf(error_msg, sizeof(error_msg), format, ap);
+    android::base::StringAppendV(&error_msg, format, ap);
     va_end(ap);
+
     uiPrint(state, error_msg);
 }
 
 // Take a sha-1 digest and return it as a newly-allocated hex string.
 char* PrintSha1(const uint8_t* digest) {
-    char* buffer = malloc(SHA_DIGEST_SIZE*2 + 1);
-    int i;
+    char* buffer = reinterpret_cast<char*>(malloc(SHA_DIGEST_LENGTH*2 + 1));
     const char* alphabet = "0123456789abcdef";
-    for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
+    size_t i;
+    for (i = 0; i < SHA_DIGEST_LENGTH; ++i) {
         buffer[i*2] = alphabet[(digest[i] >> 4) & 0xf];
         buffer[i*2+1] = alphabet[digest[i] & 0xf];
     }
@@ -97,7 +118,7 @@ char* PrintSha1(const uint8_t* digest) {
 Value* MountFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
     if (argc != 4 && argc != 5) {
-        return ErrorAbort(state, "%s() expects 4-5 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 4-5 args, got %d", name, argc);
     }
     char* fs_type;
     char* partition_type;
@@ -120,35 +141,38 @@ Value* MountFn(const char* name, State* state, int argc, Expr* argv[]) {
     }
 
     if (strlen(fs_type) == 0) {
-        ErrorAbort(state, "fs_type argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "fs_type argument to %s() can't be empty", name);
         goto done;
     }
     if (strlen(partition_type) == 0) {
-        ErrorAbort(state, "partition_type argument to %s() can't be empty",
+        ErrorAbort(state, kArgsParsingFailure, "partition_type argument to %s() can't be empty",
                    name);
         goto done;
     }
     if (strlen(location) == 0) {
-        ErrorAbort(state, "location argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "location argument to %s() can't be empty", name);
         goto done;
     }
     if (strlen(mount_point) == 0) {
-        ErrorAbort(state, "mount_point argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "mount_point argument to %s() can't be empty",
+                   name);
         goto done;
     }
 
-    char *secontext = NULL;
+    {
+        char *secontext = NULL;
 
-    if (sehandle) {
-        selabel_lookup(sehandle, &secontext, mount_point, 0755);
-        setfscreatecon(secontext);
-    }
+        if (sehandle) {
+            selabel_lookup(sehandle, &secontext, mount_point, 0755);
+            setfscreatecon(secontext);
+        }
 
-    mkdir(mount_point, 0755);
+        mkdir(mount_point, 0755);
 
-    if (secontext) {
-        freecon(secontext);
-        setfscreatecon(NULL);
+        if (secontext) {
+            freecon(secontext);
+            setfscreatecon(NULL);
+        }
     }
 
     if (strcmp(partition_type, "MTD") == 0) {
@@ -156,7 +180,7 @@ Value* MountFn(const char* name, State* state, int argc, Expr* argv[]) {
         const MtdPartition* mtd;
         mtd = mtd_find_partition_by_name(location);
         if (mtd == NULL) {
-            uiPrintf(state, "%s: no mtd partition named \"%s\"",
+            uiPrintf(state, "%s: no mtd partition named \"%s\"\n",
                     name, location);
             result = strdup("");
             goto done;
@@ -194,23 +218,25 @@ done:
 Value* IsMountedFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
     if (argc != 1) {
-        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 arg, got %d", name, argc);
     }
     char* mount_point;
     if (ReadArgs(state, argv, 1, &mount_point) < 0) {
         return NULL;
     }
     if (strlen(mount_point) == 0) {
-        ErrorAbort(state, "mount_point argument to unmount() can't be empty");
+        ErrorAbort(state, kArgsParsingFailure, "mount_point argument to unmount() can't be empty");
         goto done;
     }
 
     scan_mounted_volumes();
-    const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
-    if (vol == NULL) {
-        result = strdup("");
-    } else {
-        result = mount_point;
+    {
+        const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
+        if (vol == NULL) {
+            result = strdup("");
+        } else {
+            result = mount_point;
+        }
     }
 
 done:
@@ -222,29 +248,31 @@ done:
 Value* UnmountFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
     if (argc != 1) {
-        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 arg, got %d", name, argc);
     }
     char* mount_point;
     if (ReadArgs(state, argv, 1, &mount_point) < 0) {
         return NULL;
     }
     if (strlen(mount_point) == 0) {
-        ErrorAbort(state, "mount_point argument to unmount() can't be empty");
+        ErrorAbort(state, kArgsParsingFailure, "mount_point argument to unmount() can't be empty");
         goto done;
     }
 
     scan_mounted_volumes();
-    const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
-    if (vol == NULL) {
-        uiPrintf(state, "unmount of %s failed; no such volume\n", mount_point);
-        result = strdup("");
-    } else {
-        int ret = unmount_mounted_volume(vol);
-        if (ret != 0) {
-           uiPrintf(state, "unmount of %s failed (%d): %s\n",
-                    mount_point, ret, strerror(errno));
+    {
+        const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
+        if (vol == NULL) {
+            uiPrintf(state, "unmount of %s failed; no such volume\n", mount_point);
+            result = strdup("");
+        } else {
+            int ret = unmount_mounted_volume(vol);
+            if (ret != 0) {
+                uiPrintf(state, "unmount of %s failed (%d): %s\n",
+                         mount_point, ret, strerror(errno));
+            }
+            result = mount_point;
         }
-        result = mount_point;
     }
 
 done:
@@ -278,7 +306,7 @@ static int exec_cmd(const char* path, char* const argv[]) {
 Value* FormatFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
     if (argc != 5) {
-        return ErrorAbort(state, "%s() expects 5 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 5 args, got %d", name, argc);
     }
     char* fs_type;
     char* partition_type;
@@ -291,21 +319,22 @@ Value* FormatFn(const char* name, State* state, int argc, Expr* argv[]) {
     }
 
     if (strlen(fs_type) == 0) {
-        ErrorAbort(state, "fs_type argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "fs_type argument to %s() can't be empty", name);
         goto done;
     }
     if (strlen(partition_type) == 0) {
-        ErrorAbort(state, "partition_type argument to %s() can't be empty",
+        ErrorAbort(state, kArgsParsingFailure, "partition_type argument to %s() can't be empty",
                    name);
         goto done;
     }
     if (strlen(location) == 0) {
-        ErrorAbort(state, "location argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "location argument to %s() can't be empty", name);
         goto done;
     }
 
     if (strlen(mount_point) == 0) {
-        ErrorAbort(state, "mount_point argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "mount_point argument to %s() can't be empty",
+                   name);
         goto done;
     }
 
@@ -380,7 +409,7 @@ done:
 Value* RenameFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
     if (argc != 2) {
-        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
     }
 
     char* src_name;
@@ -390,21 +419,21 @@ Value* RenameFn(const char* name, State* state, int argc, Expr* argv[]) {
         return NULL;
     }
     if (strlen(src_name) == 0) {
-        ErrorAbort(state, "src_name argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "src_name argument to %s() can't be empty", name);
         goto done;
     }
     if (strlen(dst_name) == 0) {
-        ErrorAbort(state, "dst_name argument to %s() can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "dst_name argument to %s() can't be empty", name);
         goto done;
     }
     if (make_parents(dst_name) != 0) {
-        ErrorAbort(state, "Creating parent of %s failed, error %s",
+        ErrorAbort(state, kFileRenameFailure, "Creating parent of %s failed, error %s",
           dst_name, strerror(errno));
     } else if (access(dst_name, F_OK) == 0 && access(src_name, F_OK) != 0) {
         // File was already moved
         result = dst_name;
     } else if (rename(src_name, dst_name) != 0) {
-        ErrorAbort(state, "Rename of %s to %s failed, error %s",
+        ErrorAbort(state, kFileRenameFailure, "Rename of %s to %s failed, error %s",
           src_name, dst_name, strerror(errno));
     } else {
         result = dst_name;
@@ -417,13 +446,11 @@ done:
 }
 
 Value* DeleteFn(const char* name, State* state, int argc, Expr* argv[]) {
-    char** paths = malloc(argc * sizeof(char*));
-    int i;
-    for (i = 0; i < argc; ++i) {
+    char** paths = reinterpret_cast<char**>(malloc(argc * sizeof(char*)));
+    for (int i = 0; i < argc; ++i) {
         paths[i] = Evaluate(state, argv[i]);
         if (paths[i] == NULL) {
-            int j;
-            for (j = 0; j < i; ++i) {
+            for (int j = 0; j < i; ++j) {
                 free(paths[j]);
             }
             free(paths);
@@ -434,7 +461,7 @@ Value* DeleteFn(const char* name, State* state, int argc, Expr* argv[]) {
     bool recursive = (strcmp(name, "delete_recursive") == 0);
 
     int success = 0;
-    for (i = 0; i < argc; ++i) {
+    for (int i = 0; i < argc; ++i) {
         if ((recursive ? dirUnlinkHierarchy(paths[i]) : unlink(paths[i])) == 0)
             ++success;
         free(paths[i]);
@@ -449,7 +476,7 @@ Value* DeleteFn(const char* name, State* state, int argc, Expr* argv[]) {
 
 Value* ShowProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
-        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
     }
     char* frac_str;
     char* sec_str;
@@ -458,7 +485,8 @@ Value* ShowProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
     }
 
     double frac = strtod(frac_str, NULL);
-    int sec = strtol(sec_str, NULL, 10);
+    int sec;
+    android::base::ParseInt(sec_str, &sec);
 
     UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
     fprintf(ui->cmd_pipe, "progress %f %d\n", frac, sec);
@@ -469,7 +497,7 @@ Value* ShowProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
 
 Value* SetProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 1) {
-        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 arg, got %d", name, argc);
     }
     char* frac_str;
     if (ReadArgs(state, argv, 1, &frac_str) < 0) {
@@ -488,7 +516,7 @@ Value* SetProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
 Value* PackageExtractDirFn(const char* name, State* state,
                           int argc, Expr* argv[]) {
     if (argc != 2) {
-        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
     }
     char* zip_path;
     char* dest_path;
@@ -516,13 +544,11 @@ Value* PackageExtractDirFn(const char* name, State* state,
 Value* PackageExtractFileFn(const char* name, State* state,
                            int argc, Expr* argv[]) {
     if (argc < 1 || argc > 2) {
-        return ErrorAbort(state, "%s() expects 1 or 2 args, got %d",
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 or 2 args, got %d",
                           name, argc);
     }
     bool success = false;
 
-    UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
-
     if (argc == 2) {
         // The two-argument version extracts to a file.
 
@@ -538,14 +564,23 @@ Value* PackageExtractFileFn(const char* name, State* state,
             goto done2;
         }
 
-        FILE* f = fopen(dest_path, "wb");
-        if (f == NULL) {
-            printf("%s: can't open %s for write: %s\n",
-                    name, dest_path, strerror(errno));
-            goto done2;
+        {
+            int fd = TEMP_FAILURE_RETRY(ota_open(dest_path, O_WRONLY | O_CREAT | O_TRUNC | O_SYNC,
+                  S_IRUSR | S_IWUSR));
+            if (fd == -1) {
+                printf("%s: can't open %s for write: %s\n", name, dest_path, strerror(errno));
+                goto done2;
+            }
+            success = mzExtractZipEntryToFile(za, entry, fd);
+            if (ota_fsync(fd) == -1) {
+                printf("fsync of \"%s\" failed: %s\n", dest_path, strerror(errno));
+                success = false;
+            }
+            if (ota_close(fd) == -1) {
+                printf("close of \"%s\" failed: %s\n", dest_path, strerror(errno));
+                success = false;
+            }
         }
-        success = mzExtractZipEntryToFile(za, entry, fileno(f));
-        fclose(f);
 
       done2:
         free(zip_path);
@@ -556,13 +591,13 @@ Value* PackageExtractFileFn(const char* name, State* state,
         // as the result.
 
         char* zip_path;
-        Value* v = malloc(sizeof(Value));
+        if (ReadArgs(state, argv, 1, &zip_path) < 0) return NULL;
+
+        Value* v = reinterpret_cast<Value*>(malloc(sizeof(Value)));
         v->type = VAL_BLOB;
         v->size = -1;
         v->data = NULL;
 
-        if (ReadArgs(state, argv, 1, &zip_path) < 0) return NULL;
-
         ZipArchive* za = ((UpdaterInfo*)(state->cookie))->package_zip;
         const ZipEntry* entry = mzFindZipEntry(za, zip_path);
         if (entry == NULL) {
@@ -571,7 +606,7 @@ Value* PackageExtractFileFn(const char* name, State* state,
         }
 
         v->size = mzGetZipEntryUncompLen(entry);
-        v->data = malloc(v->size);
+        v->data = reinterpret_cast<char*>(malloc(v->size));
         if (v->data == NULL) {
             printf("%s: failed to allocate %ld bytes for %s\n",
                     name, (long)v->size, zip_path);
@@ -617,7 +652,7 @@ static int make_parents(char* name) {
 //    unlinks any previously existing src1, src2, etc before creating symlinks.
 Value* SymlinkFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc == 0) {
-        return ErrorAbort(state, "%s() expects 1+ args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1+ args, got %d", name, argc);
     }
     char* target;
     target = Evaluate(state, argv[0]);
@@ -653,7 +688,7 @@ Value* SymlinkFn(const char* name, State* state, int argc, Expr* argv[]) {
     }
     free(srcs);
     if (bad) {
-        return ErrorAbort(state, "%s: some symlinks failed", name);
+        return ErrorAbort(state, kSymlinkFailure, "%s: some symlinks failed", name);
     }
     return StringValue(strdup(""));
 }
@@ -870,41 +905,42 @@ static int do_SetMetadataRecursive(const char* filename, const struct stat *stat
 }
 
 static Value* SetMetadataFn(const char* name, State* state, int argc, Expr* argv[]) {
-    int i;
     int bad = 0;
-    static int nwarnings = 0;
     struct stat sb;
     Value* result = NULL;
 
     bool recursive = (strcmp(name, "set_metadata_recursive") == 0);
 
     if ((argc % 2) != 1) {
-        return ErrorAbort(state, "%s() expects an odd number of arguments, got %d",
-                          name, argc);
+        return ErrorAbort(state, kArgsParsingFailure,
+                          "%s() expects an odd number of arguments, got %d", name, argc);
     }
 
     char** args = ReadVarArgs(state, argc, argv);
     if (args == NULL) return NULL;
 
     if (lstat(args[0], &sb) == -1) {
-        result = ErrorAbort(state, "%s: Error on lstat of \"%s\": %s", name, args[0], strerror(errno));
+        result = ErrorAbort(state, kSetMetadataFailure, "%s: Error on lstat of \"%s\": %s",
+                            name, args[0], strerror(errno));
         goto done;
     }
 
-    struct perm_parsed_args parsed = ParsePermArgs(state, argc, args);
+    {
+        struct perm_parsed_args parsed = ParsePermArgs(state, argc, args);
 
-    if (recursive) {
-        recursive_parsed_args = parsed;
-        recursive_state = state;
-        bad += nftw(args[0], do_SetMetadataRecursive, 30, FTW_CHDIR | FTW_DEPTH | FTW_PHYS);
-        memset(&recursive_parsed_args, 0, sizeof(recursive_parsed_args));
-        recursive_state = NULL;
-    } else {
-        bad += ApplyParsedPerms(state, args[0], &sb, parsed);
+        if (recursive) {
+            recursive_parsed_args = parsed;
+            recursive_state = state;
+            bad += nftw(args[0], do_SetMetadataRecursive, 30, FTW_CHDIR | FTW_DEPTH | FTW_PHYS);
+            memset(&recursive_parsed_args, 0, sizeof(recursive_parsed_args));
+            recursive_state = NULL;
+        } else {
+            bad += ApplyParsedPerms(state, args[0], &sb, parsed);
+        }
     }
 
 done:
-    for (i = 0; i < argc; ++i) {
+    for (int i = 0; i < argc; ++i) {
         free(args[i]);
     }
     free(args);
@@ -914,7 +950,7 @@ done:
     }
 
     if (bad > 0) {
-        return ErrorAbort(state, "%s: some changes failed", name);
+        return ErrorAbort(state, kSetMetadataFailure, "%s: some changes failed", name);
     }
 
     return StringValue(strdup(""));
@@ -922,10 +958,9 @@ done:
 
 Value* GetPropFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 1) {
-        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 arg, got %d", name, argc);
     }
-    char* key;
-    key = Evaluate(state, argv[0]);
+    char* key = Evaluate(state, argv[0]);
     if (key == NULL) return NULL;
 
     char value[PROPERTY_VALUE_MAX];
@@ -952,34 +987,36 @@ Value* FileGetPropFn(const char* name, State* state, int argc, Expr* argv[]) {
 
     struct stat st;
     if (stat(filename, &st) < 0) {
-        ErrorAbort(state, "%s: failed to stat \"%s\": %s",
-                   name, filename, strerror(errno));
+        ErrorAbort(state, kFileGetPropFailure, "%s: failed to stat \"%s\": %s", name, filename,
+                   strerror(errno));
         goto done;
     }
 
 #define MAX_FILE_GETPROP_SIZE    65536
 
     if (st.st_size > MAX_FILE_GETPROP_SIZE) {
-        ErrorAbort(state, "%s too large for %s (max %d)",
-                   filename, name, MAX_FILE_GETPROP_SIZE);
+        ErrorAbort(state, kFileGetPropFailure, "%s too large for %s (max %d)", filename, name,
+                   MAX_FILE_GETPROP_SIZE);
         goto done;
     }
 
-    buffer = malloc(st.st_size+1);
+    buffer = reinterpret_cast<char*>(malloc(st.st_size+1));
     if (buffer == NULL) {
-        ErrorAbort(state, "%s: failed to alloc %lld bytes", name, (long long)st.st_size+1);
+        ErrorAbort(state, kFileGetPropFailure, "%s: failed to alloc %lld bytes", name,
+                   (long long)st.st_size+1);
         goto done;
     }
 
-    FILE* f = fopen(filename, "rb");
+    FILE* f;
+    f = fopen(filename, "rb");
     if (f == NULL) {
-        ErrorAbort(state, "%s: failed to open %s: %s",
-                   name, filename, strerror(errno));
+        ErrorAbort(state, kFileOpenFailure, "%s: failed to open %s: %s", name, filename,
+                   strerror(errno));
         goto done;
     }
 
-    if (fread(buffer, 1, st.st_size, f) != st.st_size) {
-        ErrorAbort(state, "%s: failed to read %lld bytes from %s",
+    if (ota_fread(buffer, 1, st.st_size, f) != static_cast<size_t>(st.st_size)) {
+        ErrorAbort(state, kFreadFailure, "%s: failed to read %lld bytes from %s",
                    name, (long long)st.st_size+1, filename);
         fclose(f);
         goto done;
@@ -988,7 +1025,8 @@ Value* FileGetPropFn(const char* name, State* state, int argc, Expr* argv[]) {
 
     fclose(f);
 
-    char* line = strtok(buffer, "\n");
+    char* line;
+    line = strtok(buffer, "\n");
     do {
         // skip whitespace at start of line
         while (*line && isspace(*line)) ++line;
@@ -1032,15 +1070,6 @@ Value* FileGetPropFn(const char* name, State* state, int argc, Expr* argv[]) {
     return StringValue(result);
 }
 
-
-static bool write_raw_image_cb(const unsigned char* data,
-                               int data_len, void* ctx) {
-    int r = mtd_write_data((MtdWriteContext*)ctx, (const char *)data, data_len);
-    if (r == data_len) return true;
-    printf("%s\n", strerror(errno));
-    return false;
-}
-
 // write_raw_image(filename_or_blob, partition)
 Value* WriteRawImageFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
@@ -1053,27 +1082,80 @@ Value* WriteRawImageFn(const char* name, State* state, int argc, Expr* argv[]) {
 
     char* partition = NULL;
     if (partition_value->type != VAL_STRING) {
-        ErrorAbort(state, "partition argument to %s must be string", name);
+        ErrorAbort(state, kArgsParsingFailure, "partition argument to %s must be string", name);
         goto done;
     }
     partition = partition_value->data;
     if (strlen(partition) == 0) {
-        ErrorAbort(state, "partition argument to %s can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "partition argument to %s can't be empty", name);
         goto done;
     }
     if (contents->type == VAL_STRING && strlen((char*) contents->data) == 0) {
-        ErrorAbort(state, "file argument to %s can't be empty", name);
+        ErrorAbort(state, kArgsParsingFailure, "file argument to %s can't be empty", name);
         goto done;
     }
 
-    char* filename = contents->data;
-    if (0 == restore_raw_partition(NULL, partition, filename))
-        result = strdup(partition);
-    else {
+    mtd_scan_partitions();
+    const MtdPartition* mtd;
+    mtd = mtd_find_partition_by_name(partition);
+    if (mtd == NULL) {
+        printf("%s: no mtd partition named \"%s\"\n", name, partition);
         result = strdup("");
         goto done;
     }
 
+    MtdWriteContext* ctx;
+    ctx = mtd_write_partition(mtd);
+    if (ctx == NULL) {
+        printf("%s: can't write mtd partition \"%s\"\n",
+                name, partition);
+        result = strdup("");
+        goto done;
+    }
+
+    bool success;
+
+    if (contents->type == VAL_STRING) {
+        // we're given a filename as the contents
+        char* filename = contents->data;
+        FILE* f = ota_fopen(filename, "rb");
+        if (f == NULL) {
+            printf("%s: can't open %s: %s\n", name, filename, strerror(errno));
+            result = strdup("");
+            goto done;
+        }
+
+        success = true;
+        char* buffer = reinterpret_cast<char*>(malloc(BUFSIZ));
+        int read;
+        while (success && (read = ota_fread(buffer, 1, BUFSIZ, f)) > 0) {
+            int wrote = mtd_write_data(ctx, buffer, read);
+            success = success && (wrote == read);
+        }
+        free(buffer);
+        ota_fclose(f);
+    } else {
+        // we're given a blob as the contents
+        ssize_t wrote = mtd_write_data(ctx, contents->data, contents->size);
+        success = (wrote == contents->size);
+    }
+    if (!success) {
+        printf("mtd_write_data to %s failed: %s\n",
+                partition, strerror(errno));
+    }
+
+    if (mtd_erase_blocks(ctx, -1) == -1) {
+        printf("%s: error erasing blocks of %s\n", name, partition);
+    }
+    if (mtd_write_close(ctx) != 0) {
+        printf("%s: error closing write of %s\n", name, partition);
+    }
+
+    printf("%s %s partition\n",
+           success ? "wrote" : "failed to write", partition);
+
+    result = success ? partition : strdup("");
+
 done:
     if (result != partition) FreeValue(partition_value);
     FreeValue(contents);
@@ -1088,13 +1170,12 @@ Value* ApplyPatchSpaceFn(const char* name, State* state,
         return NULL;
     }
 
-    char* endptr;
-    size_t bytes = strtol(bytes_str, &endptr, 10);
-    if (bytes == 0 && endptr == bytes_str) {
-        ErrorAbort(state, "%s(): can't parse \"%s\" as byte count\n\n",
+    size_t bytes;
+    if (!android::base::ParseUint(bytes_str, &bytes)) {
+        ErrorAbort(state, kArgsParsingFailure, "%s(): can't parse \"%s\" as byte count\n\n",
                    name, bytes_str);
         free(bytes_str);
-        return NULL;
+        return nullptr;
     }
 
     return StringValue(strdup(CacheSizeCheck(bytes) ? "" : "t"));
@@ -1104,9 +1185,8 @@ Value* ApplyPatchSpaceFn(const char* name, State* state,
 
 Value* ApplyPatchFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc < 6 || (argc % 2) == 1) {
-        return ErrorAbort(state, "%s(): expected at least 6 args and an "
-                                 "even number, got %d",
-                          name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s(): expected at least 6 args and an "
+                                 "even number, got %d", name, argc);
     }
 
     char* source_filename;
@@ -1118,57 +1198,52 @@ Value* ApplyPatchFn(const char* name, State* state, int argc, Expr* argv[]) {
         return NULL;
     }
 
-    char* endptr;
-    size_t target_size = strtol(target_size_str, &endptr, 10);
-    if (target_size == 0 && endptr == target_size_str) {
-        ErrorAbort(state, "%s(): can't parse \"%s\" as byte count",
+    size_t target_size;
+    if (!android::base::ParseUint(target_size_str, &target_size)) {
+        ErrorAbort(state, kArgsParsingFailure, "%s(): can't parse \"%s\" as byte count",
                    name, target_size_str);
         free(source_filename);
         free(target_filename);
         free(target_sha1);
         free(target_size_str);
-        return NULL;
+        return nullptr;
     }
 
     int patchcount = (argc-4) / 2;
-    Value** patches = ReadValueVarArgs(state, argc-4, argv+4);
-
-    int i;
-    for (i = 0; i < patchcount; ++i) {
-        if (patches[i*2]->type != VAL_STRING) {
-            ErrorAbort(state, "%s(): sha-1 #%d is not string", name, i);
-            break;
+    std::unique_ptr<Value*, decltype(&free)> arg_values(ReadValueVarArgs(state, argc-4, argv+4),
+                                                        free);
+    if (!arg_values) {
+        return nullptr;
+    }
+    std::vector<std::unique_ptr<Value, decltype(&FreeValue)>> patch_shas;
+    std::vector<std::unique_ptr<Value, decltype(&FreeValue)>> patches;
+    // Protect values by unique_ptrs first to get rid of memory leak.
+    for (int i = 0; i < patchcount * 2; i += 2) {
+        patch_shas.emplace_back(arg_values.get()[i], FreeValue);
+        patches.emplace_back(arg_values.get()[i+1], FreeValue);
+    }
+
+    for (int i = 0; i < patchcount; ++i) {
+        if (patch_shas[i]->type != VAL_STRING) {
+            ErrorAbort(state, kArgsParsingFailure, "%s(): sha-1 #%d is not string", name, i);
+            return nullptr;
         }
-        if (patches[i*2+1]->type != VAL_BLOB) {
-            ErrorAbort(state, "%s(): patch #%d is not blob", name, i);
-            break;
+        if (patches[i]->type != VAL_BLOB) {
+            ErrorAbort(state, kArgsParsingFailure, "%s(): patch #%d is not blob", name, i);
+            return nullptr;
         }
     }
-    if (i != patchcount) {
-        for (i = 0; i < patchcount*2; ++i) {
-            FreeValue(patches[i]);
-        }
-        free(patches);
-        return NULL;
-    }
 
-    char** patch_sha_str = malloc(patchcount * sizeof(char*));
-    for (i = 0; i < patchcount; ++i) {
-        patch_sha_str[i] = patches[i*2]->data;
-        patches[i*2]->data = NULL;
-        FreeValue(patches[i*2]);
-        patches[i] = patches[i*2+1];
+    std::vector<char*> patch_sha_str;
+    std::vector<Value*> patch_ptrs;
+    for (int i = 0; i < patchcount; ++i) {
+        patch_sha_str.push_back(patch_shas[i]->data);
+        patch_ptrs.push_back(patches[i].get());
     }
 
     int result = applypatch(source_filename, target_filename,
                             target_sha1, target_size,
-                            patchcount, patch_sha_str, patches, NULL);
-
-    for (i = 0; i < patchcount; ++i) {
-        FreeValue(patches[i]);
-    }
-    free(patch_sha_str);
-    free(patches);
+                            patchcount, patch_sha_str.data(), patch_ptrs.data(), NULL);
 
     return StringValue(strdup(result == 0 ? "t" : ""));
 }
@@ -1177,7 +1252,7 @@ Value* ApplyPatchFn(const char* name, State* state, int argc, Expr* argv[]) {
 Value* ApplyPatchCheckFn(const char* name, State* state,
                          int argc, Expr* argv[]) {
     if (argc < 1) {
-        return ErrorAbort(state, "%s(): expected at least 1 arg, got %d",
+        return ErrorAbort(state, kArgsParsingFailure, "%s(): expected at least 1 arg, got %d",
                           name, argc);
     }
 
@@ -1200,33 +1275,29 @@ Value* ApplyPatchCheckFn(const char* name, State* state,
     return StringValue(strdup(result == 0 ? "t" : ""));
 }
 
+// This is the updater side handler for ui_print() in edify script. Contents
+// will be sent over to the recovery side for on-screen display.
 Value* UIPrintFn(const char* name, State* state, int argc, Expr* argv[]) {
     char** args = ReadVarArgs(state, argc, argv);
     if (args == NULL) {
         return NULL;
     }
 
-    int size = 0;
-    int i;
-    for (i = 0; i < argc; ++i) {
-        size += strlen(args[i]);
-    }
-    char* buffer = malloc(size+1);
-    size = 0;
-    for (i = 0; i < argc; ++i) {
-        strcpy(buffer+size, args[i]);
-        size += strlen(args[i]);
+    std::string buffer;
+    for (int i = 0; i < argc; ++i) {
+        buffer += args[i];
         free(args[i]);
     }
     free(args);
-    buffer[size] = '\0';
+
+    buffer += "\n";
     uiPrint(state, buffer);
-    return StringValue(buffer);
+    return StringValue(strdup(buffer.c_str()));
 }
 
 Value* WipeCacheFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 0) {
-        return ErrorAbort(state, "%s() expects no args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects no args, got %d", name, argc);
     }
     fprintf(((UpdaterInfo*)(state->cookie))->cmd_pipe, "wipe_cache\n");
     return StringValue(strdup("t"));
@@ -1234,14 +1305,14 @@ Value* WipeCacheFn(const char* name, State* state, int argc, Expr* argv[]) {
 
 Value* RunProgramFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc < 1) {
-        return ErrorAbort(state, "%s() expects at least 1 arg", name);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects at least 1 arg", name);
     }
     char** args = ReadVarArgs(state, argc, argv);
     if (args == NULL) {
         return NULL;
     }
 
-    char** args2 = malloc(sizeof(char*) * (argc+1));
+    char** args2 = reinterpret_cast<char**>(malloc(sizeof(char*) * (argc+1)));
     memcpy(args2, args, sizeof(char*) * argc);
     args2[argc] = NULL;
 
@@ -1288,27 +1359,30 @@ Value* RunProgramFn(const char* name, State* state, int argc, Expr* argv[]) {
 //
 Value* Sha1CheckFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc < 1) {
-        return ErrorAbort(state, "%s() expects at least 1 arg", name);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects at least 1 arg", name);
     }
 
-    Value** args = ReadValueVarArgs(state, argc, argv);
-    if (args == NULL) {
-        return NULL;
+    std::unique_ptr<Value*, decltype(&free)> arg_values(ReadValueVarArgs(state, argc, argv), free);
+    if (arg_values == nullptr) {
+        return nullptr;
+    }
+    std::vector<std::unique_ptr<Value, decltype(&FreeValue)>> args;
+    for (int i = 0; i < argc; ++i) {
+        args.emplace_back(arg_values.get()[i], FreeValue);
     }
 
     if (args[0]->size < 0) {
         return StringValue(strdup(""));
     }
-    uint8_t digest[SHA_DIGEST_SIZE];
-    SHA_hash(args[0]->data, args[0]->size, digest);
-    FreeValue(args[0]);
+    uint8_t digest[SHA_DIGEST_LENGTH];
+    SHA1(reinterpret_cast<uint8_t*>(args[0]->data), args[0]->size, digest);
 
     if (argc == 1) {
         return StringValue(PrintSha1(digest));
     }
 
     int i;
-    uint8_t* arg_digest = malloc(SHA_DIGEST_SIZE);
+    uint8_t arg_digest[SHA_DIGEST_LENGTH];
     for (i = 1; i < argc; ++i) {
         if (args[i]->type != VAL_STRING) {
             printf("%s(): arg %d is not a string; skipping",
@@ -1317,48 +1391,43 @@ Value* Sha1CheckFn(const char* name, State* state, int argc, Expr* argv[]) {
             // Warn about bad args and skip them.
             printf("%s(): error parsing \"%s\" as sha-1; skipping",
                    name, args[i]->data);
-        } else if (memcmp(digest, arg_digest, SHA_DIGEST_SIZE) == 0) {
+        } else if (memcmp(digest, arg_digest, SHA_DIGEST_LENGTH) == 0) {
             break;
         }
-        FreeValue(args[i]);
     }
     if (i >= argc) {
         // Didn't match any of the hex strings; return false.
         return StringValue(strdup(""));
     }
-    // Found a match; free all the remaining arguments and return the
-    // matched one.
-    int j;
-    for (j = i+1; j < argc; ++j) {
-        FreeValue(args[j]);
-    }
-    return args[i];
+    // Found a match.
+    return args[i].release();
 }
 
 // Read a local file and return its contents (the Value* returned
 // is actually a FileContents*).
 Value* ReadFileFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 1) {
-        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 arg, got %d", name, argc);
     }
     char* filename;
     if (ReadArgs(state, argv, 1, &filename) < 0) return NULL;
 
-    Value* v = malloc(sizeof(Value));
+    Value* v = static_cast<Value*>(malloc(sizeof(Value)));
+    if (v == nullptr) {
+        return nullptr;
+    }
     v->type = VAL_BLOB;
+    v->size = -1;
+    v->data = nullptr;
 
     FileContents fc;
     if (LoadFileContents(filename, &fc) != 0) {
-        free(filename);
-        v->size = -1;
-        v->data = NULL;
-        free(fc.data);
-        return v;
+        v->data = static_cast<char*>(malloc(fc.data.size()));
+        if (v->data != nullptr) {
+            memcpy(v->data, fc.data.data(), fc.data.size());
+            v->size = fc.data.size();
+        }
     }
-
-    v->size = fc.size;
-    v->data = (char*)fc.data;
-
     free(filename);
     return v;
 }
@@ -1374,7 +1443,7 @@ Value* ReadFileFn(const char* name, State* state, int argc, Expr* argv[]) {
 // partition.
 Value* RebootNowFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
-        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
     }
 
     char* filename;
@@ -1387,7 +1456,7 @@ Value* RebootNowFn(const char* name, State* state, int argc, Expr* argv[]) {
     memset(buffer, 0, sizeof(((struct bootloader_message*)0)->command));
     FILE* f = fopen(filename, "r+b");
     fseek(f, offsetof(struct bootloader_message, command), SEEK_SET);
-    fwrite(buffer, sizeof(((struct bootloader_message*)0)->command), 1, f);
+    ota_fwrite(buffer, sizeof(((struct bootloader_message*)0)->command), 1, f);
     fclose(f);
     free(filename);
 
@@ -1400,7 +1469,7 @@ Value* RebootNowFn(const char* name, State* state, int argc, Expr* argv[]) {
 
     sleep(5);
     free(property);
-    ErrorAbort(state, "%s() failed to reboot", name);
+    ErrorAbort(state, kRebootFailure, "%s() failed to reboot", name);
     return NULL;
 }
 
@@ -1416,7 +1485,7 @@ Value* RebootNowFn(const char* name, State* state, int argc, Expr* argv[]) {
 // bytes.
 Value* SetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
-        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
     }
 
     char* filename;
@@ -1435,7 +1504,7 @@ Value* SetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
         to_write = max_size;
         stagestr[max_size-1] = 0;
     }
-    fwrite(stagestr, to_write, 1, f);
+    ota_fwrite(stagestr, to_write, 1, f);
     fclose(f);
 
     free(stagestr);
@@ -1446,7 +1515,7 @@ Value* SetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
 // is the block device for the misc partition.
 Value* GetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 1) {
-        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 1 arg, got %d", name, argc);
     }
 
     char* filename;
@@ -1455,7 +1524,7 @@ Value* GetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
     char buffer[sizeof(((struct bootloader_message*)0)->stage)];
     FILE* f = fopen(filename, "rb");
     fseek(f, offsetof(struct bootloader_message, stage), SEEK_SET);
-    fread(buffer, sizeof(buffer), 1, f);
+    ota_fread(buffer, sizeof(buffer), 1, f);
     fclose(f);
     buffer[sizeof(buffer)-1] = '\0';
 
@@ -1464,28 +1533,29 @@ Value* GetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
 
 Value* WipeBlockDeviceFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
-        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
     }
 
     char* filename;
     char* len_str;
     if (ReadArgs(state, argv, 2, &filename, &len_str) < 0) return NULL;
 
-    size_t len = strtoull(len_str, NULL, 0);
-    int fd = open(filename, O_WRONLY, 0644);
+    size_t len;
+    android::base::ParseUint(len_str, &len);
+    int fd = ota_open(filename, O_WRONLY, 0644);
     int success = wipe_block_device(fd, len);
 
     free(filename);
     free(len_str);
 
-    close(fd);
+    ota_close(fd);
 
     return StringValue(strdup(success ? "t" : ""));
 }
 
 Value* EnableRebootFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 0) {
-        return ErrorAbort(state, "%s() expects no args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects no args, got %d", name, argc);
     }
     UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
     fprintf(ui->cmd_pipe, "enable_reboot\n");
@@ -1495,23 +1565,22 @@ Value* EnableRebootFn(const char* name, State* state, int argc, Expr* argv[]) {
 Value* Tune2FsFn(const char* name, State* state, int argc, Expr* argv[]) {
 #ifdef HAVE_LIBTUNE2FS
     if (argc == 0) {
-        return ErrorAbort(state, "%s() expects args, got %d", name, argc);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() expects args, got %d", name, argc);
     }
 
     char** args = ReadVarArgs(state, argc, argv);
     if (args == NULL) {
-        return ErrorAbort(state, "%s() could not read args", name);
+        return ErrorAbort(state, kArgsParsingFailure, "%s() could not read args", name);
     }
 
-    int i;
-    char** args2 = malloc(sizeof(char*) * (argc+1));
+    char** args2 = reinterpret_cast<char**>(malloc(sizeof(char*) * (argc+1)));
     // Tune2fs expects the program name as its args[0]
     args2[0] = strdup(name);
-    for (i = 0; i < argc; ++i) {
+    for (int i = 0; i < argc; ++i) {
        args2[i + 1] = args[i];
     }
     int result = tune2fs_main(argc + 1, args2);
-    for (i = 0; i < argc; ++i) {
+    for (int i = 0; i < argc; ++i) {
         free(args[i]);
     }
     free(args);
@@ -1519,7 +1588,8 @@ Value* Tune2FsFn(const char* name, State* state, int argc, Expr* argv[]) {
     free(args2[0]);
     free(args2);
     if (result != 0) {
-        return ErrorAbort(state, "%s() returned error code %d", name, result);
+        return ErrorAbort(state, kTune2FsFailure, "%s() returned error code %d",
+                          name, result);
     }
     return StringValue(strdup("t"));
 #else
diff --git a/updater/install.h b/updater/install.h
index 659c8b41c..70e343404 100644
--- a/updater/install.h
+++ b/updater/install.h
@@ -19,6 +19,9 @@
 
 void RegisterInstallFunctions();
 
+// uiPrintf function prints msg to screen as well as logs
+void uiPrintf(State* state, const char* format, ...);
+
 static int make_parents(char* name);
 
 #endif
diff --git a/updater/updater.c b/updater/updater.cpp
index 479675da7..452c3530f 100644
--- a/updater/updater.c
+++ b/updater/updater.cpp
@@ -26,6 +26,7 @@
 #include "blockimg.h"
 #include "minzip/Zip.h"
 #include "minzip/SysUtil.h"
+#include "config.h"
 
 // Generated by the makefile, this function defines the
 // RegisterDeviceExtensions() function, which calls all the
@@ -38,6 +39,8 @@
 #define SELINUX_CONTEXTS_ZIP "file_contexts"
 #define SELINUX_CONTEXTS_TMP "/tmp/file_contexts"
 
+extern bool have_eio_error;
+
 struct selabel_handle *sehandle;
 
 int main(int argc, char** argv) {
@@ -48,7 +51,7 @@ int main(int argc, char** argv) {
     setbuf(stdout, NULL);
     setbuf(stderr, NULL);
 
-    if (argc != 4) {
+    if (argc != 4 && argc != 5) {
         printf("unexpected number of arguments (%d)\n", argc);
         return 1;
     }
@@ -85,6 +88,7 @@ int main(int argc, char** argv) {
                argv[3], strerror(err));
         return 3;
     }
+    ota_io_init(&za);
 
     const ZipEntry* script_entry = mzFindZipEntry(&za, SCRIPT_NAME);
     if (script_entry == NULL) {
@@ -92,7 +96,7 @@ int main(int argc, char** argv) {
         return 4;
     }
 
-    char* script = malloc(script_entry->uncompLen+1);
+    char* script = reinterpret_cast<char*>(malloc(script_entry->uncompLen+1));
     if (!mzReadZipEntry(&za, script_entry, script, script_entry->uncompLen)) {
         printf("failed to read script from package\n");
         return 5;
@@ -166,7 +170,20 @@ int main(int argc, char** argv) {
     state.script = script;
     state.errmsg = NULL;
 
+    if (argc == 5) {
+        if (strcmp(argv[4], "retry") == 0) {
+            state.is_retry = true;
+        } else {
+            printf("unexpected argument: %s", argv[4]);
+        }
+    }
+
     char* result = Evaluate(&state, root);
+
+    if (have_eio_error) {
+        fprintf(cmd_pipe, "retry_update\n");
+    }
+
     if (result == NULL) {
         if (state.errmsg == NULL) {
             printf("script aborted (no error message)\n");
@@ -175,11 +192,28 @@ int main(int argc, char** argv) {
             printf("script aborted: %s\n", state.errmsg);
             char* line = strtok(state.errmsg, "\n");
             while (line) {
+                // Parse the error code in abort message.
+                // Example: "E30: This package is for bullhead devices."
+                if (*line == 'E') {
+                    if (sscanf(line, "E%u: ", &state.error_code) != 1) {
+                         printf("Failed to parse error code: [%s]\n", line);
+                    }
+                }
                 fprintf(cmd_pipe, "ui_print %s\n", line);
                 line = strtok(NULL, "\n");
             }
             fprintf(cmd_pipe, "ui_print\n");
         }
+
+        if (state.error_code != kNoError) {
+            fprintf(cmd_pipe, "log error: %d\n", state.error_code);
+            // Cause code should provide additional information about the abort;
+            // report only when an error exists.
+            if (state.cause_code != kNoCause) {
+                fprintf(cmd_pipe, "log cause: %d\n", state.cause_code);
+            }
+        }
+
         free(state.errmsg);
         return 7;
     } else {