diff options
Diffstat (limited to 'bootloader_message/bootloader_message.cpp')
| -rw-r--r-- | bootloader_message/bootloader_message.cpp | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp new file mode 100644 index 000000000..62d8c6785 --- /dev/null +++ b/bootloader_message/bootloader_message.cpp @@ -0,0 +1,179 @@ +/* + * Copyright (C) 2016 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_message/bootloader_message.h> + +#include <errno.h> +#include <fcntl.h> +#include <string.h> + +#include <string> +#include <vector> + +#include <android-base/file.h> +#include <android-base/properties.h> +#include <android-base/stringprintf.h> +#include <android-base/unique_fd.h> +#include <fs_mgr.h> + +static struct fstab* read_fstab(std::string* err) { + std::string ro_hardware = android::base::GetProperty("ro.hardware", ""); + if (ro_hardware.empty()) { + *err = "failed to get ro.hardware"; + return nullptr; + } + // The fstab path is always "/fstab.${ro.hardware}". + std::string fstab_path = "/fstab." + ro_hardware; + struct fstab* fstab = fs_mgr_read_fstab(fstab_path.c_str()); + if (fstab == nullptr) { + *err = "failed to read " + fstab_path; + } + return fstab; +} + +static std::string get_misc_blk_device(std::string* err) { + struct fstab* fstab = read_fstab(err); + if (fstab == nullptr) { + return ""; + } + fstab_rec* record = fs_mgr_get_entry_for_mount_point(fstab, "/misc"); + if (record == nullptr) { + *err = "failed to find /misc partition"; + return ""; + } + return record->blk_device; +} + +// In recovery mode, recovery can get started and try to access the misc +// device before the kernel has actually created it. +static bool wait_for_device(const std::string& blk_device, std::string* err) { + int tries = 0; + int ret; + err->clear(); + do { + ++tries; + struct stat buf; + ret = stat(blk_device.c_str(), &buf); + if (ret == -1) { + *err += android::base::StringPrintf("failed to stat %s try %d: %s\n", + blk_device.c_str(), tries, strerror(errno)); + sleep(1); + } + } while (ret && tries < 10); + + if (ret) { + *err += android::base::StringPrintf("failed to stat %s\n", blk_device.c_str()); + } + return ret == 0; +} + +static bool read_misc_partition(void* p, size_t size, size_t offset, std::string* err) { + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } + if (!wait_for_device(misc_blk_device, err)) { + return false; + } + android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY | O_SYNC)); + if (fd.get() == -1) { + *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + if (lseek(fd.get(), static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) { + *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + if (!android::base::ReadFully(fd.get(), p, size)) { + *err = android::base::StringPrintf("failed to read %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + return true; +} + +static bool write_misc_partition(const void* p, size_t size, size_t offset, std::string* err) { + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } + android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY | O_SYNC)); + if (fd.get() == -1) { + *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + if (lseek(fd.get(), static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) { + *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + if (!android::base::WriteFully(fd.get(), p, size)) { + *err = android::base::StringPrintf("failed to write %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + // TODO: O_SYNC and fsync duplicates each other? + if (fsync(fd.get()) == -1) { + *err = android::base::StringPrintf("failed to fsync %s: %s", misc_blk_device.c_str(), + strerror(errno)); + return false; + } + return true; +} + +bool read_bootloader_message(bootloader_message* boot, std::string* err) { + return read_misc_partition(boot, sizeof(*boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err); +} + +bool write_bootloader_message(const bootloader_message& boot, std::string* err) { + return write_misc_partition(&boot, sizeof(boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err); +} + +bool clear_bootloader_message(std::string* err) { + bootloader_message boot = {}; + return write_bootloader_message(boot, err); +} + +bool write_bootloader_message(const std::vector<std::string>& options, std::string* err) { + bootloader_message boot = {}; + strlcpy(boot.command, "boot-recovery", sizeof(boot.command)); + strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery)); + for (const auto& s : options) { + strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery)); + if (s.back() != '\n') { + strlcat(boot.recovery, "\n", sizeof(boot.recovery)); + } + } + return write_bootloader_message(boot, err); +} + +bool read_wipe_package(std::string* package_data, size_t size, std::string* err) { + package_data->resize(size); + return read_misc_partition(&(*package_data)[0], size, WIPE_PACKAGE_OFFSET_IN_MISC, err); +} + +bool write_wipe_package(const std::string& package_data, std::string* err) { + return write_misc_partition(package_data.data(), package_data.size(), + WIPE_PACKAGE_OFFSET_IN_MISC, err); +} + +extern "C" bool write_bootloader_message(const char* options) { + std::string err; + return write_bootloader_message({options}, &err); +} |