1 files changed, 202 insertions, 0 deletions

diff --git a/bootloader.cpp b/bootloader.cpp
new file mode 100644
index 000000000..baaddc55f
--- /dev/null
+++ b/bootloader.cpp
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2008 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 "bootloader.h"
+#include "common.h"
+#include "mtdutils/mtdutils.h"
+#include "roots.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
+static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
+static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v);
+static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v);
+
+int get_bootloader_message(struct bootloader_message *out) {
+    Volume* v = volume_for_path("/misc");
+    if (v == NULL) {
+      LOGE("Cannot load volume /misc!\n");
+      return -1;
+    }
+    if (strcmp(v->fs_type, "mtd") == 0) {
+        return get_bootloader_message_mtd(out, v);
+    } else if (strcmp(v->fs_type, "emmc") == 0) {
+        return get_bootloader_message_block(out, v);
+    }
+    LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
+    return -1;
+}
+
+int set_bootloader_message(const struct bootloader_message *in) {
+    Volume* v = volume_for_path("/misc");
+    if (v == NULL) {
+      LOGE("Cannot load volume /misc!\n");
+      return -1;
+    }
+    if (strcmp(v->fs_type, "mtd") == 0) {
+        return set_bootloader_message_mtd(in, v);
+    } else if (strcmp(v->fs_type, "emmc") == 0) {
+        return set_bootloader_message_block(in, v);
+    }
+    LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
+    return -1;
+}
+
+// ------------------------------
+// for misc partitions on MTD
+// ------------------------------
+
+static const int MISC_PAGES = 3;         // number of pages to save
+static const int MISC_COMMAND_PAGE = 1;  // bootloader command is this page
+
+static int get_bootloader_message_mtd(struct bootloader_message *out,
+                                      const Volume* v) {
+    size_t write_size;
+    mtd_scan_partitions();
+    const MtdPartition *part = mtd_find_partition_by_name(v->device);
+    if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
+        LOGE("Can't find %s\n", v->device);
+        return -1;
+    }
+
+    MtdReadContext *read = mtd_read_partition(part);
+    if (read == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+
+    const ssize_t size = write_size * MISC_PAGES;
+    char data[size];
+    ssize_t r = mtd_read_data(read, data, size);
+    if (r != size) LOGE("Can't read %s\n(%s)\n", v->device, strerror(errno));
+    mtd_read_close(read);
+    if (r != size) return -1;
+
+    memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
+    return 0;
+}
+static int set_bootloader_message_mtd(const struct bootloader_message *in,
+                                      const Volume* v) {
+    size_t write_size;
+    mtd_scan_partitions();
+    const MtdPartition *part = mtd_find_partition_by_name(v->device);
+    if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
+        LOGE("Can't find %s\n", v->device);
+        return -1;
+    }
+
+    MtdReadContext *read = mtd_read_partition(part);
+    if (read == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+
+    ssize_t size = write_size * MISC_PAGES;
+    char data[size];
+    ssize_t r = mtd_read_data(read, data, size);
+    if (r != size) LOGE("Can't read %s\n(%s)\n", v->device, strerror(errno));
+    mtd_read_close(read);
+    if (r != size) return -1;
+
+    memcpy(&data[write_size * MISC_COMMAND_PAGE], in, sizeof(*in));
+
+    MtdWriteContext *write = mtd_write_partition(part);
+    if (write == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    if (mtd_write_data(write, data, size) != size) {
+        LOGE("Can't write %s\n(%s)\n", v->device, strerror(errno));
+        mtd_write_close(write);
+        return -1;
+    }
+    if (mtd_write_close(write)) {
+        LOGE("Can't finish %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+
+    LOGI("Set boot command \"%s\"\n", in->command[0] != 255 ? in->command : "");
+    return 0;
+}
+
+
+// ------------------------------------
+// for misc partitions on block devices
+// ------------------------------------
+
+static void wait_for_device(const char* fn) {
+    int tries = 0;
+    int ret;
+    struct stat buf;
+    do {
+        ++tries;
+        ret = stat(fn, &buf);
+        if (ret) {
+            printf("stat %s try %d: %s\n", fn, tries, strerror(errno));
+            sleep(1);
+        }
+    } while (ret && tries < 10);
+    if (ret) {
+        printf("failed to stat %s\n", fn);
+    }
+}
+
+static int get_bootloader_message_block(struct bootloader_message *out,
+                                        const Volume* v) {
+    wait_for_device(v->device);
+    FILE* f = fopen(v->device, "rb");
+    if (f == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    struct bootloader_message temp;
+    int count = fread(&temp, sizeof(temp), 1, f);
+    if (count != 1) {
+        LOGE("Failed reading %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    if (fclose(f) != 0) {
+        LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    memcpy(out, &temp, sizeof(temp));
+    return 0;
+}
+
+static int set_bootloader_message_block(const struct bootloader_message *in,
+                                        const Volume* v) {
+    wait_for_device(v->device);
+    FILE* f = fopen(v->device, "wb");
+    if (f == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    int count = fwrite(in, sizeof(*in), 1, f);
+    if (count != 1) {
+        LOGE("Failed writing %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    if (fclose(f) != 0) {
+        LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    return 0;
+}