/* * 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. */ #ifndef _RECOVERY_BOOTLOADER_H #define _RECOVERY_BOOTLOADER_H #include /* 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 * each other. * * The command field is updated by linux when it wants to * reboot into recovery or to update radio or bootloader firmware. * It is also updated by the bootloader when firmware update * is complete (to boot into recovery for any final cleanup) * * The status field is written by the bootloader after the * completion of an "update-radio" or "update-hboot" command. * * The recovery field is only written by linux and used * for the system to send a message to recovery or the * other way around. * * The stage field is written by packages which restart themselves * multiple times, so that the UI can reflect which invocation of the * package it is. If the value is of the format "#/#" (eg, "1/3"), * the UI will add a simple indicator of that status. * * 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]; char status[32]; char recovery[768]; // The 'recovery' field used to be 1024 bytes. It has only ever // been used to store the recovery command line, so 768 bytes // should be plenty. We carve off the last 256 bytes to store the // 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]; // 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 /* Read and write the bootloader command from the "misc" partition. * These return zero on success. */ int get_bootloader_message(struct bootloader_message *out); int set_bootloader_message(const struct bootloader_message *in); #endif