1 /* 2 * This is from the Android Project, 3 * Repository: https://android.googlesource.com/platform/bootable/recovery/ 4 * File: bootloader_message/include/bootloader_message/bootloader_message.h 5 * Commit: 8b309f6970ab3b7c53cc529c51a2cb44e1c7a7e1 6 * 7 * Copyright (C) 2008 The Android Open Source Project 8 * 9 * SPDX-License-Identifier: BSD-2-Clause 10 */ 11 12 #ifndef __ANDROID_BOOTLOADER_MESSAGE_H 13 #define __ANDROID_BOOTLOADER_MESSAGE_H 14 15 /* compiler.h defines the types that otherwise are included from stdint.h and 16 * stddef.h 17 */ 18 #include <compiler.h> 19 20 /* Spaces used by misc partition are as below: 21 * 0 - 2K Bootloader Message 22 * 2K - 16K Used by Vendor's bootloader (the 2K - 4K range may be optionally used 23 * as bootloader_message_ab struct) 24 * 16K - 32K Used by uncrypt and recovery to store wipe_package for A/B devices 25 * 32K - 64K System space, used for miscellaneous AOSP features (virtual A/B metadata). 26 * Note that these offsets are admitted by bootloader,recovery and uncrypt, so they 27 * are not configurable without changing all of them. 28 */ 29 static const size_t ANDROID_BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0; 30 static const size_t ANDROID_WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024; 31 static const size_t ANDROID_VIRTUAL_AB_METADATA_OFFSET_IN_MISC = 32 * 1024; 32 33 /* Bootloader Message (2-KiB) 34 * 35 * This structure describes the content of a block in flash 36 * that is used for recovery and the bootloader to talk to 37 * each other. 38 * 39 * The command field is updated by linux when it wants to 40 * reboot into recovery or to update radio or bootloader firmware. 41 * It is also updated by the bootloader when firmware update 42 * is complete (to boot into recovery for any final cleanup) 43 * 44 * The status field is written by the bootloader after the 45 * completion of an "update-radio" or "update-hboot" command. 46 * 47 * The recovery field is only written by linux and used 48 * for the system to send a message to recovery or the 49 * other way around. 50 * 51 * The stage field is written by packages which restart themselves 52 * multiple times, so that the UI can reflect which invocation of the 53 * package it is. If the value is of the format "#/#" (eg, "1/3"), 54 * the UI will add a simple indicator of that status. 55 * 56 * We used to have slot_suffix field for A/B boot control metadata in 57 * this struct, which gets unintentionally cleared by recovery or 58 * uncrypt. Move it into struct bootloader_message_ab to avoid the 59 * issue. 60 */ 61 struct android_bootloader_message { 62 char command[32]; 63 char status[32]; 64 char recovery[768]; 65 66 /* The 'recovery' field used to be 1024 bytes. It has only ever 67 * been used to store the recovery command line, so 768 bytes 68 * should be plenty. We carve off the last 256 bytes to store the 69 * stage string (for multistage packages) and possible future 70 * expansion. */ 71 char stage[32]; 72 73 /* The 'reserved' field used to be 224 bytes when it was initially 74 * carved off from the 1024-byte recovery field. Bump it up to 75 * 1184-byte so that the entire bootloader_message struct rounds up 76 * to 2048-byte. */ 77 char reserved[1184]; 78 }; 79 80 /** 81 * We must be cautious when changing the bootloader_message struct size, 82 * because A/B-specific fields may end up with different offsets. 83 */ 84 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 85 static_assert(sizeof(struct android_bootloader_message) == 2048, 86 "struct bootloader_message size changes, which may break A/B devices"); 87 #endif 88 89 /** 90 * The A/B-specific bootloader message structure (4-KiB). 91 * 92 * We separate A/B boot control metadata from the regular bootloader 93 * message struct and keep it here. Everything that's A/B-specific 94 * stays after struct bootloader_message, which should be managed by 95 * the A/B-bootloader or boot control HAL. 96 * 97 * The slot_suffix field is used for A/B implementations where the 98 * bootloader does not set the androidboot.ro.boot.slot_suffix kernel 99 * commandline parameter. This is used by fs_mgr to mount /system and 100 * other partitions with the slotselect flag set in fstab. A/B 101 * implementations are free to use all 32 bytes and may store private 102 * data past the first NUL-byte in this field. It is encouraged, but 103 * not mandatory, to use 'struct bootloader_control' described below. 104 */ 105 struct android_bootloader_message_ab { 106 struct android_bootloader_message message; 107 char slot_suffix[32]; 108 109 /* Round up the entire struct to 4096-byte. */ 110 char reserved[2016]; 111 }; 112 113 /** 114 * Be cautious about the struct size change, in case we put anything post 115 * bootloader_message_ab struct (b/29159185). 116 */ 117 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 118 static_assert(sizeof(struct android_bootloader_message_ab) == 4096, 119 "struct bootloader_message_ab size changes"); 120 #endif 121 122 #define ANDROID_BOOT_CTRL_MAGIC 0x42414342 /* Bootloader Control AB */ 123 #define ANDROID_BOOT_CTRL_VERSION 1 124 125 struct android_slot_metadata { 126 /* Slot priority with 15 meaning highest priority, 1 lowest 127 * priority and 0 the slot is unbootable. */ 128 uint8_t priority : 4; 129 /* Number of times left attempting to boot this slot. */ 130 uint8_t tries_remaining : 3; 131 /* 1 if this slot has booted successfully, 0 otherwise. */ 132 uint8_t successful_boot : 1; 133 /* 1 if this slot is corrupted from a dm-verity corruption, 0 */ 134 /* otherwise. */ 135 uint8_t verity_corrupted : 1; 136 /* Reserved for further use. */ 137 uint8_t reserved : 7; 138 } __attribute__((packed)); 139 140 /* Bootloader Control AB 141 * 142 * This struct can be used to manage A/B metadata. It is designed to 143 * be put in the 'slot_suffix' field of the 'bootloader_message' 144 * structure described above. It is encouraged to use the 145 * 'bootloader_control' structure to store the A/B metadata, but not 146 * mandatory. 147 */ 148 struct android_bootloader_control { 149 /* NUL terminated active slot suffix. */ 150 char slot_suffix[4]; 151 /* Bootloader Control AB magic number (see BOOT_CTRL_MAGIC). */ 152 uint32_t magic; 153 /* Version of struct being used (see BOOT_CTRL_VERSION). */ 154 uint8_t version; 155 /* Number of slots being managed. */ 156 uint8_t nb_slot : 3; 157 /* Number of times left attempting to boot recovery. */ 158 uint8_t recovery_tries_remaining : 3; 159 /* Ensure 4-bytes alignment for slot_info field. */ 160 uint8_t reserved0[2]; 161 /* Per-slot information. Up to 4 slots. */ 162 struct android_slot_metadata slot_info[4]; 163 /* Reserved for further use. */ 164 uint8_t reserved1[8]; 165 /* CRC32 of all 28 bytes preceding this field (little endian 166 * format). */ 167 uint32_t crc32_le; 168 } __attribute__((packed)); 169 170 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 171 static_assert(sizeof(struct android_bootloader_control) == 172 sizeof(((struct android_bootloader_message_ab *)0)->slot_suffix), 173 "struct bootloader_control has wrong size"); 174 #endif 175 176 #endif /* __ANDROID_BOOTLOADER_MESSAGE_H */ 177