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Move libboot_control to boot_control 1.1

Browse source 
It should belong to the default /misc implementation of boot control
1.1. Right now, it's only used by cuttlefish. So move it over to reduce
confusion in bootloader_message.

Bug: 131775112
Test: build
Change-Id: If09bc6f4cc8adf74c8798048c8e54ec94566abaa
This commit is contained in:
Tianjie Xu 2019-12-16 16:07:27 -08:00
parent 38f07f0ba4
commit dc4d2a70db
5 changed files with 0 additions and 791 deletions
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61
boot_control/Android.bp
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@ -1,61 +0,0 @@
//
// Copyright (C) 2018 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.
//
cc_defaults {
name: "libboot_control_defaults",
vendor: true,
recovery_available: true,
relative_install_path: "hw",
cflags: [
"-D_FILE_OFFSET_BITS=64",
"-Werror",
"-Wall",
"-Wextra",
],
shared_libs: [
"android.hardware.boot@1.1",
"libbase",
"liblog",
],
static_libs: [
"libbootloader_message_vendor",
"libfstab",
],
}
cc_library_static {
name: "libboot_control",
defaults: ["libboot_control_defaults"],
export_include_dirs: ["include"],
srcs: ["libboot_control.cpp"],
}
cc_library_shared {
name: "bootctrl.default",
defaults: ["libboot_control_defaults"],
srcs: ["legacy_boot_control.cpp"],
static_libs: [
"libboot_control",
],
shared_libs: [
"libhardware",
],
}

89
boot_control/include/libboot_control/libboot_control.h
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@ -1,89 +0,0 @@
//
// Copyright (C) 2019 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.
//
#pragma once
#include <string>
#include <android/hardware/boot/1.1/IBootControl.h>
namespace android {
namespace bootable {
// Helper library to implement the IBootControl HAL using the misc partition.
class BootControl {
using MergeStatus = ::android::hardware::boot::V1_1::MergeStatus;
public:
bool Init();
unsigned int GetNumberSlots();
unsigned int GetCurrentSlot();
bool MarkBootSuccessful();
bool SetActiveBootSlot(unsigned int slot);
bool SetSlotAsUnbootable(unsigned int slot);
bool SetSlotBootable(unsigned int slot);
bool IsSlotBootable(unsigned int slot);
const char* GetSuffix(unsigned int slot);
bool IsSlotMarkedSuccessful(unsigned int slot);
bool SetSnapshotMergeStatus(MergeStatus status);
MergeStatus GetSnapshotMergeStatus();
bool IsValidSlot(unsigned int slot);
const std::string& misc_device() const {
return misc_device_;
}
private:
// Whether this object was initialized with data from the bootloader message
// that doesn't change until next reboot.
bool initialized_ = false;
// The path to the misc_device as reported in the fstab.
std::string misc_device_;
// The number of slots present on the device.
unsigned int num_slots_ = 0;
// The slot where we are running from.
unsigned int current_slot_ = 0;
};
// Helper functions to write the Virtual A/B merge status message. These are
// separate because BootControl uses bootloader_control_ab in vendor space,
// whereas the Virtual A/B merge status is in system space. A HAL might not
// use bootloader_control_ab, but may want to use the AOSP method of maintaining
// the merge status.
// If the Virtual A/B message has not yet been initialized, then initialize it.
// This should be called when the BootControl HAL first loads.
//
// If the Virtual A/B message in misc was already initialized, true is returned.
// If initialization was attempted, but failed, false is returned, and the HAL
// should fail to load.
bool InitMiscVirtualAbMessageIfNeeded();
// Save the current merge status as well as the current slot.
bool SetMiscVirtualAbMergeStatus(unsigned int current_slot,
android::hardware::boot::V1_1::MergeStatus status);
// Return the current merge status. If the saved status is SNAPSHOTTED but the
// slot hasn't changed, the status returned will be NONE.
bool GetMiscVirtualAbMergeStatus(unsigned int current_slot,
android::hardware::boot::V1_1::MergeStatus* status);
} // namespace bootable
} // namespace android

115
boot_control/legacy_boot_control.cpp
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@ -1,115 +0,0 @@
/*
* Copyright (C) 2015 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 <string>
#include <hardware/boot_control.h>
#include <hardware/hardware.h>
#include <libboot_control/libboot_control.h>
using android::bootable::BootControl;
struct boot_control_private_t {
// The base struct needs to be first in the list.
boot_control_module_t base;
BootControl impl;
};
namespace {
void BootControl_init(boot_control_module_t* module) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
impl.Init();
}
unsigned int BootControl_getNumberSlots(boot_control_module_t* module) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.GetNumberSlots();
}
unsigned int BootControl_getCurrentSlot(boot_control_module_t* module) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.GetCurrentSlot();
}
int BootControl_markBootSuccessful(boot_control_module_t* module) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.MarkBootSuccessful() ? 0 : -1;
}
int BootControl_setActiveBootSlot(boot_control_module_t* module, unsigned int slot) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.SetActiveBootSlot(slot) ? 0 : -1;
}
int BootControl_setSlotAsUnbootable(struct boot_control_module* module, unsigned int slot) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.SetSlotAsUnbootable(slot) ? 0 : -1;
}
int BootControl_isSlotBootable(struct boot_control_module* module, unsigned int slot) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.IsSlotBootable(slot) ? 0 : -1;
}
int BootControl_isSlotMarkedSuccessful(struct boot_control_module* module, unsigned int slot) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.IsSlotMarkedSuccessful(slot) ? 0 : -1;
}
const char* BootControl_getSuffix(boot_control_module_t* module, unsigned int slot) {
auto& impl = reinterpret_cast<boot_control_private_t*>(module)->impl;
return impl.GetSuffix(slot);
}
static int BootControl_open(const hw_module_t* module __unused, const char* id __unused,
hw_device_t** device __unused) {
/* Nothing to do currently. */
return 0;
}
struct hw_module_methods_t BootControl_methods = {
.open = BootControl_open,
};
} // namespace
boot_control_private_t HAL_MODULE_INFO_SYM = {
.base =
{
.common =
{
.tag = HARDWARE_MODULE_TAG,
.module_api_version = BOOT_CONTROL_MODULE_API_VERSION_0_1,
.hal_api_version = HARDWARE_HAL_API_VERSION,
.id = BOOT_CONTROL_HARDWARE_MODULE_ID,
.name = "AOSP reference bootctrl HAL",
.author = "The Android Open Source Project",
.methods = &BootControl_methods,
},
.init = BootControl_init,
.getNumberSlots = BootControl_getNumberSlots,
.getCurrentSlot = BootControl_getCurrentSlot,
.markBootSuccessful = BootControl_markBootSuccessful,
.setActiveBootSlot = BootControl_setActiveBootSlot,
.setSlotAsUnbootable = BootControl_setSlotAsUnbootable,
.isSlotBootable = BootControl_isSlotBootable,
.getSuffix = BootControl_getSuffix,
.isSlotMarkedSuccessful = BootControl_isSlotMarkedSuccessful,
},
};

424
boot_control/libboot_control.cpp
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@ -1,424 +0,0 @@
/*
* Copyright (C) 2015 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 <libboot_control/libboot_control.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <string>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <bootloader_message/bootloader_message.h>
namespace android {
namespace bootable {
using ::android::hardware::boot::V1_1::MergeStatus;
// The number of boot attempts that should be made from a new slot before
// rolling back to the previous slot.
constexpr unsigned int kDefaultBootAttempts = 7;
static_assert(kDefaultBootAttempts < 8, "tries_remaining field only has 3 bits");
constexpr unsigned int kMaxNumSlots =
sizeof(bootloader_control::slot_info) / sizeof(bootloader_control::slot_info[0]);
constexpr const char* kSlotSuffixes[kMaxNumSlots] = { "_a", "_b", "_c", "_d" };
constexpr off_t kBootloaderControlOffset = offsetof(bootloader_message_ab, slot_suffix);
static uint32_t CRC32(const uint8_t* buf, size_t size) {
static uint32_t crc_table[256];
// Compute the CRC-32 table only once.
if (!crc_table[1]) {
for (uint32_t i = 0; i < 256; ++i) {
uint32_t crc = i;
for (uint32_t j = 0; j < 8; ++j) {
uint32_t mask = -(crc & 1);
crc = (crc >> 1) ^ (0xEDB88320 & mask);
}
crc_table[i] = crc;
}
}
uint32_t ret = -1;
for (size_t i = 0; i < size; ++i) {
ret = (ret >> 8) ^ crc_table[(ret ^ buf[i]) & 0xFF];
}
return ~ret;
}
// Return the little-endian representation of the CRC-32 of the first fields
// in |boot_ctrl| up to the crc32_le field.
uint32_t BootloaderControlLECRC(const bootloader_control* boot_ctrl) {
return htole32(
CRC32(reinterpret_cast<const uint8_t*>(boot_ctrl), offsetof(bootloader_control, crc32_le)));
}
bool LoadBootloaderControl(const std::string& misc_device, bootloader_control* buffer) {
android::base::unique_fd fd(open(misc_device.c_str(), O_RDONLY));
if (fd.get() == -1) {
PLOG(ERROR) << "failed to open " << misc_device;
return false;
}
if (lseek(fd, kBootloaderControlOffset, SEEK_SET) != kBootloaderControlOffset) {
PLOG(ERROR) << "failed to lseek " << misc_device;
return false;
}
if (!android::base::ReadFully(fd.get(), buffer, sizeof(bootloader_control))) {
PLOG(ERROR) << "failed to read " << misc_device;
return false;
}
return true;
}
bool UpdateAndSaveBootloaderControl(const std::string& misc_device, bootloader_control* buffer) {
buffer->crc32_le = BootloaderControlLECRC(buffer);
android::base::unique_fd fd(open(misc_device.c_str(), O_WRONLY | O_SYNC));
if (fd.get() == -1) {
PLOG(ERROR) << "failed to open " << misc_device;
return false;
}
if (lseek(fd.get(), kBootloaderControlOffset, SEEK_SET) != kBootloaderControlOffset) {
PLOG(ERROR) << "failed to lseek " << misc_device;
return false;
}
if (!android::base::WriteFully(fd.get(), buffer, sizeof(bootloader_control))) {
PLOG(ERROR) << "failed to write " << misc_device;
return false;
}
return true;
}
void InitDefaultBootloaderControl(BootControl* control, bootloader_control* boot_ctrl) {
memset(boot_ctrl, 0, sizeof(*boot_ctrl));
unsigned int current_slot = control->GetCurrentSlot();
if (current_slot < kMaxNumSlots) {
strlcpy(boot_ctrl->slot_suffix, kSlotSuffixes[current_slot], sizeof(boot_ctrl->slot_suffix));
}
boot_ctrl->magic = BOOT_CTRL_MAGIC;
boot_ctrl->version = BOOT_CTRL_VERSION;
// Figure out the number of slots by checking if the partitions exist,
// otherwise assume the maximum supported by the header.
boot_ctrl->nb_slot = kMaxNumSlots;
std::string base_path = control->misc_device();
size_t last_path_sep = base_path.rfind('/');
if (last_path_sep != std::string::npos) {
// We test the existence of the "boot" partition on each possible slot,
// which is a partition required by Android Bootloader Requirements.
base_path = base_path.substr(0, last_path_sep + 1) + "boot";
int last_existing_slot = -1;
int first_missing_slot = -1;
for (unsigned int slot = 0; slot < kMaxNumSlots; ++slot) {
std::string partition_path = base_path + kSlotSuffixes[slot];
struct stat part_stat;
int err = stat(partition_path.c_str(), &part_stat);
if (!err) {
last_existing_slot = slot;
LOG(INFO) << "Found slot: " << kSlotSuffixes[slot];
} else if (err < 0 && errno == ENOENT && first_missing_slot == -1) {
first_missing_slot = slot;
}
}
// We only declare that we found the actual number of slots if we found all
// the boot partitions up to the number of slots, and no boot partition
// after that. Not finding any of the boot partitions implies a problem so
// we just leave the number of slots in the maximum value.
if ((last_existing_slot != -1 && last_existing_slot + 1 == first_missing_slot) ||
(first_missing_slot == -1 && last_existing_slot + 1 == kMaxNumSlots)) {
boot_ctrl->nb_slot = last_existing_slot + 1;
LOG(INFO) << "Found a system with " << last_existing_slot + 1 << " slots.";
}
}
for (unsigned int slot = 0; slot < kMaxNumSlots; ++slot) {
slot_metadata entry = {};
if (slot < boot_ctrl->nb_slot) {
entry.priority = 7;
entry.tries_remaining = kDefaultBootAttempts;
entry.successful_boot = 0;
} else {
entry.priority = 0; // Unbootable
}
// When the boot_control stored on disk is invalid, we assume that the
// current slot is successful. The bootloader should repair this situation
// before booting and write a valid boot_control slot, so if we reach this
// stage it means that the misc partition was corrupted since boot.
if (current_slot == slot) {
entry.successful_boot = 1;
}
boot_ctrl->slot_info[slot] = entry;
}
boot_ctrl->recovery_tries_remaining = 0;
boot_ctrl->crc32_le = BootloaderControlLECRC(boot_ctrl);
}
// Return the index of the slot suffix passed or -1 if not a valid slot suffix.
int SlotSuffixToIndex(const char* suffix) {
for (unsigned int slot = 0; slot < kMaxNumSlots; ++slot) {
if (!strcmp(kSlotSuffixes[slot], suffix)) return slot;
}
return -1;
}
// Initialize the boot_control_private struct with the information from
// the bootloader_message buffer stored in |boot_ctrl|. Returns whether the
// initialization succeeded.
bool BootControl::Init() {
if (initialized_) return true;
// Initialize the current_slot from the read-only property. If the property
// was not set (from either the command line or the device tree), we can later
// initialize it from the bootloader_control struct.
std::string suffix_prop = android::base::GetProperty("ro.boot.slot_suffix", "");
if (suffix_prop.empty()) {
LOG(ERROR) << "Slot suffix property is not set";
return false;
}
current_slot_ = SlotSuffixToIndex(suffix_prop.c_str());
std::string err;
std::string device = get_bootloader_message_blk_device(&err);
if (device.empty()) {
LOG(ERROR) << "Could not find bootloader message block device: " << err;
return false;
}
bootloader_control boot_ctrl;
if (!LoadBootloaderControl(device.c_str(), &boot_ctrl)) {
LOG(ERROR) << "Failed to load bootloader control block";
return false;
}
// Note that since there isn't a module unload function this memory is leaked.
// We use `device` below sometimes, so it's not moved out of here.
misc_device_ = device;
initialized_ = true;
// Validate the loaded data, otherwise we will destroy it and re-initialize it
// with the current information.
uint32_t computed_crc32 = BootloaderControlLECRC(&boot_ctrl);
if (boot_ctrl.crc32_le != computed_crc32) {
LOG(WARNING) << "Invalid boot control found, expected CRC-32 0x" << std::hex << computed_crc32
<< " but found 0x" << std::hex << boot_ctrl.crc32_le << ". Re-initializing.";
InitDefaultBootloaderControl(this, &boot_ctrl);
UpdateAndSaveBootloaderControl(device.c_str(), &boot_ctrl);
}
if (!InitMiscVirtualAbMessageIfNeeded()) {
return false;
}
num_slots_ = boot_ctrl.nb_slot;
return true;
}
unsigned int BootControl::GetNumberSlots() {
return num_slots_;
}
unsigned int BootControl::GetCurrentSlot() {
return current_slot_;
}
bool BootControl::MarkBootSuccessful() {
bootloader_control bootctrl;
if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false;
bootctrl.slot_info[current_slot_].successful_boot = 1;
// tries_remaining == 0 means that the slot is not bootable anymore, make
// sure we mark the current slot as bootable if it succeeds in the last
// attempt.
bootctrl.slot_info[current_slot_].tries_remaining = 1;
return UpdateAndSaveBootloaderControl(misc_device_, &bootctrl);
}
bool BootControl::SetActiveBootSlot(unsigned int slot) {
if (slot >= kMaxNumSlots || slot >= num_slots_) {
// Invalid slot number.
return false;
}
bootloader_control bootctrl;
if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false;
// Set every other slot with a lower priority than the new "active" slot.
const unsigned int kActivePriority = 15;
const unsigned int kActiveTries = 6;
for (unsigned int i = 0; i < num_slots_; ++i) {
if (i != slot) {
if (bootctrl.slot_info[i].priority >= kActivePriority)
bootctrl.slot_info[i].priority = kActivePriority - 1;
}
}
// Note that setting a slot as active doesn't change the successful bit.
// The successful bit will only be changed by setSlotAsUnbootable().
bootctrl.slot_info[slot].priority = kActivePriority;
bootctrl.slot_info[slot].tries_remaining = kActiveTries;
// Setting the current slot as active is a way to revert the operation that
// set *another* slot as active at the end of an updater. This is commonly
// used to cancel the pending update. We should only reset the verity_corrpted
// bit when attempting a new slot, otherwise the verity bit on the current
// slot would be flip.
if (slot != current_slot_) bootctrl.slot_info[slot].verity_corrupted = 0;
return UpdateAndSaveBootloaderControl(misc_device_, &bootctrl);
}
bool BootControl::SetSlotAsUnbootable(unsigned int slot) {
if (slot >= kMaxNumSlots || slot >= num_slots_) {
// Invalid slot number.
return false;
}
bootloader_control bootctrl;
if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false;
// The only way to mark a slot as unbootable, regardless of the priority is to
// set the tries_remaining to 0.
bootctrl.slot_info[slot].successful_boot = 0;
bootctrl.slot_info[slot].tries_remaining = 0;
return UpdateAndSaveBootloaderControl(misc_device_, &bootctrl);
}
bool BootControl::IsSlotBootable(unsigned int slot) {
if (slot >= kMaxNumSlots || slot >= num_slots_) {
// Invalid slot number.
return false;
}
bootloader_control bootctrl;
if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false;
return bootctrl.slot_info[slot].tries_remaining != 0;
}
bool BootControl::IsSlotMarkedSuccessful(unsigned int slot) {
if (slot >= kMaxNumSlots || slot >= num_slots_) {
// Invalid slot number.
return false;
}
bootloader_control bootctrl;
if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false;
return bootctrl.slot_info[slot].successful_boot && bootctrl.slot_info[slot].tries_remaining;
}
bool BootControl::IsValidSlot(unsigned int slot) {
return slot < kMaxNumSlots && slot < num_slots_;
}
bool BootControl::SetSnapshotMergeStatus(MergeStatus status) {
return SetMiscVirtualAbMergeStatus(current_slot_, status);
}
MergeStatus BootControl::GetSnapshotMergeStatus() {
MergeStatus status;
if (!GetMiscVirtualAbMergeStatus(current_slot_, &status)) {
return MergeStatus::UNKNOWN;
}
return status;
}
const char* BootControl::GetSuffix(unsigned int slot) {
if (slot >= kMaxNumSlots || slot >= num_slots_) {
return nullptr;
}
return kSlotSuffixes[slot];
}
bool InitMiscVirtualAbMessageIfNeeded() {
std::string err;
misc_virtual_ab_message message;
if (!ReadMiscVirtualAbMessage(&message, &err)) {
LOG(ERROR) << "Could not read merge status: " << err;
return false;
}
if (message.version == MISC_VIRTUAL_AB_MESSAGE_VERSION &&
message.magic == MISC_VIRTUAL_AB_MAGIC_HEADER) {
// Already initialized.
return true;
}
message = {};
message.version = MISC_VIRTUAL_AB_MESSAGE_VERSION;
message.magic = MISC_VIRTUAL_AB_MAGIC_HEADER;
if (!WriteMiscVirtualAbMessage(message, &err)) {
LOG(ERROR) << "Could not write merge status: " << err;
return false;
}
return true;
}
bool SetMiscVirtualAbMergeStatus(unsigned int current_slot,
android::hardware::boot::V1_1::MergeStatus status) {
std::string err;
misc_virtual_ab_message message;
if (!ReadMiscVirtualAbMessage(&message, &err)) {
LOG(ERROR) << "Could not read merge status: " << err;
return false;
}
message.merge_status = static_cast<uint8_t>(status);
message.source_slot = current_slot;
if (!WriteMiscVirtualAbMessage(message, &err)) {
LOG(ERROR) << "Could not write merge status: " << err;
return false;
}
return true;
}
bool GetMiscVirtualAbMergeStatus(unsigned int current_slot,
android::hardware::boot::V1_1::MergeStatus* status) {
std::string err;
misc_virtual_ab_message message;
if (!ReadMiscVirtualAbMessage(&message, &err)) {
LOG(ERROR) << "Could not read merge status: " << err;
return false;
}
// If the slot reverted after having created a snapshot, then the snapshot will
// be thrown away at boot. Thus we don't count this as being in a snapshotted
// state.
*status = static_cast<MergeStatus>(message.merge_status);
if (*status == MergeStatus::SNAPSHOTTED && current_slot == message.source_slot) {
*status = MergeStatus::NONE;
}
return true;
}
} // namespace bootable
} // namespace android

102
bootloader_message/include/bootloader_message/bootloader_message.h
View file

@ -83,108 +83,6 @@ struct bootloader_message {
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.
*
* The update_channel field is used to store the Omaha update channel
* if update_engine is compiled with Omaha support.
*/
struct bootloader_message_ab {
struct bootloader_message message;
char slot_suffix[32];
char update_channel[128];
// Round up the entire struct to 4096-byte.
char reserved[1888];
};
/**
* 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;
// Status of any pending snapshot merge of dynamic partitions.
uint8_t merge_status : 3;
// Ensure 4-bytes alignment for slot_info field.
uint8_t reserved0[1];
// 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
// Holds Virtual A/B merge status information. Current version is 1. New fields
// must be added to the end.
struct misc_virtual_ab_message {