diff options
Diffstat (limited to 'bootloader_message')
| -rw-r--r-- | bootloader_message/Android.mk | 1 | ||||
| -rw-r--r-- | bootloader_message/bootloader_message.cpp | 98 | ||||
| -rw-r--r-- | bootloader_message/include/bootloader_message/bootloader_message.h | 144 |
3 files changed, 202 insertions, 41 deletions
diff --git a/bootloader_message/Android.mk b/bootloader_message/Android.mk index 815ac67d7..a8c50819b 100644 --- a/bootloader_message/Android.mk +++ b/bootloader_message/Android.mk @@ -19,6 +19,7 @@ LOCAL_CLANG := true LOCAL_SRC_FILES := bootloader_message.cpp LOCAL_MODULE := libbootloader_message LOCAL_STATIC_LIBRARIES := libbase libfs_mgr +LOCAL_CFLAGS := -Werror LOCAL_C_INCLUDES := $(LOCAL_PATH)/include LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include include $(BUILD_STATIC_LIBRARY) diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp index 9de7dff40..9a5671843 100644 --- a/bootloader_message/bootloader_message.cpp +++ b/bootloader_message/bootloader_message.cpp @@ -19,25 +19,24 @@ #include <errno.h> #include <fcntl.h> #include <string.h> -#include <sys/system_properties.h> #include <string> #include <vector> #include <android-base/file.h> +#include <android-base/properties.h> #include <android-base/stringprintf.h> #include <android-base/unique_fd.h> #include <fs_mgr.h> static struct fstab* read_fstab(std::string* err) { - // The fstab path is always "/fstab.${ro.hardware}". - std::string fstab_path = "/fstab."; - char value[PROP_VALUE_MAX]; - if (__system_property_get("ro.hardware", value) == 0) { + std::string ro_hardware = android::base::GetProperty("ro.hardware", ""); + if (ro_hardware.empty()) { *err = "failed to get ro.hardware"; return nullptr; } - fstab_path += value; + // 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; @@ -81,26 +80,23 @@ static bool wait_for_device(const std::string& blk_device, std::string* err) { 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; - } +static bool read_misc_partition(void* p, size_t size, const std::string& misc_blk_device, + size_t offset, std::string* err) { if (!wait_for_device(misc_blk_device, err)) { return false; } android::base::unique_fd fd(open(misc_blk_device.c_str(), O_RDONLY)); - if (fd.get() == -1) { + if (fd == -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)) { + if (lseek(fd, 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)) { + if (!android::base::ReadFully(fd, p, size)) { *err = android::base::StringPrintf("failed to read %s: %s", misc_blk_device.c_str(), strerror(errno)); return false; @@ -108,30 +104,25 @@ static bool read_misc_partition(void* p, size_t size, size_t offset, std::string 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) { +static bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device, + size_t offset, std::string* err) { + android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY)); + if (fd == -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)) { + if (lseek(fd, 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)) { + if (!android::base::WriteFully(fd, 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) { + if (fsync(fd) == -1) { *err = android::base::StringPrintf("failed to fsync %s: %s", misc_blk_device.c_str(), strerror(errno)); return false; @@ -139,12 +130,32 @@ static bool write_misc_partition(const void* p, size_t size, size_t offset, std: return true; } +bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device, + std::string* err) { + return read_misc_partition(boot, sizeof(*boot), misc_blk_device, + BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err); +} + bool read_bootloader_message(bootloader_message* boot, std::string* err) { - return read_misc_partition(boot, sizeof(*boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err); + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } + return read_bootloader_message_from(boot, misc_blk_device, err); +} + +bool write_bootloader_message_to(const bootloader_message& boot, const std::string& misc_blk_device, + std::string* err) { + return write_misc_partition(&boot, sizeof(boot), misc_blk_device, + 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); + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } + return write_bootloader_message_to(boot, misc_blk_device, err); } bool clear_bootloader_message(std::string* err) { @@ -165,16 +176,43 @@ bool write_bootloader_message(const std::vector<std::string>& options, std::stri return write_bootloader_message(boot, err); } +bool write_reboot_bootloader(std::string* err) { + bootloader_message boot; + if (!read_bootloader_message(&boot, err)) { + return false; + } + if (boot.command[0] != '\0') { + *err = "Bootloader command pending."; + return false; + } + strlcpy(boot.command, "bootonce-bootloader", sizeof(boot.command)); + return write_bootloader_message(boot, err); +} + bool read_wipe_package(std::string* package_data, size_t size, std::string* err) { + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } package_data->resize(size); - return read_misc_partition(&(*package_data)[0], size, WIPE_PACKAGE_OFFSET_IN_MISC, err); + return read_misc_partition(&(*package_data)[0], size, misc_blk_device, + 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(), + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } + return write_misc_partition(package_data.data(), package_data.size(), misc_blk_device, WIPE_PACKAGE_OFFSET_IN_MISC, err); } +extern "C" bool write_reboot_bootloader(void) { + std::string err; + return write_reboot_bootloader(&err); +} + extern "C" bool write_bootloader_message(const char* options) { std::string err; return write_bootloader_message({options}, &err); diff --git a/bootloader_message/include/bootloader_message/bootloader_message.h b/bootloader_message/include/bootloader_message/bootloader_message.h index c63aeca6f..b3d2182df 100644 --- a/bootloader_message/include/bootloader_message/bootloader_message.h +++ b/bootloader_message/include/bootloader_message/bootloader_message.h @@ -17,18 +17,21 @@ #ifndef _BOOTLOADER_MESSAGE_H #define _BOOTLOADER_MESSAGE_H +#include <assert.h> #include <stddef.h> +#include <stdint.h> // Spaces used by misc partition are as below: -// 0 - 2K Bootloader Message -// 2K - 16K Used by Vendor's bootloader +// 0 - 2K For bootloader_message +// 2K - 16K Used by Vendor's bootloader (the 2K - 4K range may be optionally used +// as bootloader_message_ab struct) // 16K - 64K Used by uncrypt and recovery to store wipe_package for A/B devices // Note that these offsets are admitted by bootloader,recovery and uncrypt, so they // are not configurable without changing all of them. static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0; static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024; -/* Bootloader Message +/* Bootloader Message (2-KiB) * * This structure describes the content of a block in flash * that is used for recovery and the bootloader to talk to @@ -51,12 +54,10 @@ static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024; * package it is. If the value is of the format "#/#" (eg, "1/3"), * the UI will add a simple indicator of that status. * - * The slot_suffix field is used for A/B implementations where the - * bootloader does not set the androidboot.ro.boot.slot_suffix kernel - * commandline parameter. This is used by fs_mgr to mount /system and - * other partitions with the slotselect flag set in fstab. A/B - * implementations are free to use all 32 bytes and may store private - * data past the first NUL-byte in this field. + * We used to have slot_suffix field for A/B boot control metadata in + * this struct, which gets unintentionally cleared by recovery or + * uncrypt. Move it into struct bootloader_message_ab to avoid the + * issue. */ struct bootloader_message { char command[32]; @@ -69,23 +70,143 @@ struct bootloader_message { // stage string (for multistage packages) and possible future // expansion. char stage[32]; + + // The 'reserved' field used to be 224 bytes when it was initially + // carved off from the 1024-byte recovery field. Bump it up to + // 1184-byte so that the entire bootloader_message struct rounds up + // to 2048-byte. + char reserved[1184]; +}; + +/** + * We must be cautious when changing the bootloader_message struct size, + * because A/B-specific fields may end up with different offsets. + */ +#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) +static_assert(sizeof(struct bootloader_message) == 2048, + "struct bootloader_message size changes, which may break A/B devices"); +#endif + +/** + * The A/B-specific bootloader message structure (4-KiB). + * + * We separate A/B boot control metadata from the regular bootloader + * message struct and keep it here. Everything that's A/B-specific + * stays after struct bootloader_message, which should be managed by + * the A/B-bootloader or boot control HAL. + * + * The slot_suffix field is used for A/B implementations where the + * bootloader does not set the androidboot.ro.boot.slot_suffix kernel + * commandline parameter. This is used by fs_mgr to mount /system and + * other partitions with the slotselect flag set in fstab. A/B + * implementations are free to use all 32 bytes and may store private + * data past the first NUL-byte in this field. It is encouraged, but + * not mandatory, to use 'struct bootloader_control' described below. + */ +struct bootloader_message_ab { + struct bootloader_message message; char slot_suffix[32]; - char reserved[192]; + + // Round up the entire struct to 4096-byte. + char reserved[2016]; }; +/** + * Be cautious about the struct size change, in case we put anything post + * bootloader_message_ab struct (b/29159185). + */ +#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) +static_assert(sizeof(struct bootloader_message_ab) == 4096, + "struct bootloader_message_ab size changes"); +#endif + +#define BOOT_CTRL_MAGIC 0x42414342 /* Bootloader Control AB */ +#define BOOT_CTRL_VERSION 1 + +struct slot_metadata { + // Slot priority with 15 meaning highest priority, 1 lowest + // priority and 0 the slot is unbootable. + uint8_t priority : 4; + // Number of times left attempting to boot this slot. + uint8_t tries_remaining : 3; + // 1 if this slot has booted successfully, 0 otherwise. + uint8_t successful_boot : 1; + // 1 if this slot is corrupted from a dm-verity corruption, 0 + // otherwise. + uint8_t verity_corrupted : 1; + // Reserved for further use. + uint8_t reserved : 7; +} __attribute__((packed)); + +/* Bootloader Control AB + * + * This struct can be used to manage A/B metadata. It is designed to + * be put in the 'slot_suffix' field of the 'bootloader_message' + * structure described above. It is encouraged to use the + * 'bootloader_control' structure to store the A/B metadata, but not + * mandatory. + */ +struct bootloader_control { + // NUL terminated active slot suffix. + char slot_suffix[4]; + // Bootloader Control AB magic number (see BOOT_CTRL_MAGIC). + uint32_t magic; + // Version of struct being used (see BOOT_CTRL_VERSION). + uint8_t version; + // Number of slots being managed. + uint8_t nb_slot : 3; + // Number of times left attempting to boot recovery. + uint8_t recovery_tries_remaining : 3; + // Ensure 4-bytes alignment for slot_info field. + uint8_t reserved0[2]; + // Per-slot information. Up to 4 slots. + struct slot_metadata slot_info[4]; + // Reserved for further use. + uint8_t reserved1[8]; + // CRC32 of all 28 bytes preceding this field (little endian + // format). + uint32_t crc32_le; +} __attribute__((packed)); + +#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) +static_assert(sizeof(struct bootloader_control) == + sizeof(((struct bootloader_message_ab *)0)->slot_suffix), + "struct bootloader_control has wrong size"); +#endif + #ifdef __cplusplus #include <string> #include <vector> +// Read bootloader message into boot. Error message will be set in err. bool read_bootloader_message(bootloader_message* boot, std::string* err); + +// Read bootloader message from the specified misc device into boot. +bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device, + std::string* err); + +// Write bootloader message to BCB. bool write_bootloader_message(const bootloader_message& boot, std::string* err); + +// Write bootloader message to the specified BCB device. +bool write_bootloader_message_to(const bootloader_message& boot, + const std::string& misc_blk_device, std::string* err); + +// Write bootloader message (boots into recovery with the options) to BCB. bool write_bootloader_message(const std::vector<std::string>& options, std::string* err); + +// Clear BCB. bool clear_bootloader_message(std::string* err); +// Writes the reboot-bootloader reboot reason to the bootloader_message. +bool write_reboot_bootloader(std::string* err); + +// Read the wipe package from BCB (from offset WIPE_PACKAGE_OFFSET_IN_MISC). bool read_wipe_package(std::string* package_data, size_t size, std::string* err); -bool write_wipe_package(const std::string& package_data, std::string* err); +// Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC). +bool write_wipe_package(const std::string& package_data, std::string* err); #else @@ -93,6 +214,7 @@ bool write_wipe_package(const std::string& package_data, std::string* err); // C Interface. bool write_bootloader_message(const char* options); +bool write_reboot_bootloader(void); #endif // ifdef __cplusplus |