1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef _BOOTLOADER_MESSAGE_H 18 #define _BOOTLOADER_MESSAGE_H 19 20 #include <assert.h> 21 #include <stddef.h> 22 #include <stdint.h> 23 24 // Spaces used by misc partition are as below: 25 // 0 - 2K For bootloader_message 26 // 2K - 16K Used by Vendor's bootloader (the 2K - 4K range may be optionally used 27 // as bootloader_message_ab struct) 28 // 16K - 64K Used by uncrypt and recovery to store wipe_package for A/B devices 29 // Note that these offsets are admitted by bootloader,recovery and uncrypt, so they 30 // are not configurable without changing all of them. 31 static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0; 32 static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024; 33 34 /* Bootloader Message (2-KiB) 35 * 36 * This structure describes the content of a block in flash 37 * that is used for recovery and the bootloader to talk to 38 * each other. 39 * 40 * The command field is updated by linux when it wants to 41 * reboot into recovery or to update radio or bootloader firmware. 42 * It is also updated by the bootloader when firmware update 43 * is complete (to boot into recovery for any final cleanup) 44 * 45 * The status field was used by the bootloader after the completion 46 * of an "update-radio" or "update-hboot" command, which has been 47 * deprecated since Froyo. 48 * 49 * The recovery field is only written by linux and used 50 * for the system to send a message to recovery or the 51 * other way around. 52 * 53 * The stage field is written by packages which restart themselves 54 * multiple times, so that the UI can reflect which invocation of the 55 * package it is. If the value is of the format "#/#" (eg, "1/3"), 56 * the UI will add a simple indicator of that status. 57 * 58 * We used to have slot_suffix field for A/B boot control metadata in 59 * this struct, which gets unintentionally cleared by recovery or 60 * uncrypt. Move it into struct bootloader_message_ab to avoid the 61 * issue. 62 */ 63 struct bootloader_message { 64 char command[32]; 65 char status[32]; 66 char recovery[768]; 67 68 // The 'recovery' field used to be 1024 bytes. It has only ever 69 // been used to store the recovery command line, so 768 bytes 70 // should be plenty. We carve off the last 256 bytes to store the 71 // stage string (for multistage packages) and possible future 72 // expansion. 73 char stage[32]; 74 75 // The 'reserved' field used to be 224 bytes when it was initially 76 // carved off from the 1024-byte recovery field. Bump it up to 77 // 1184-byte so that the entire bootloader_message struct rounds up 78 // to 2048-byte. 79 char reserved[1184]; 80 }; 81 82 /** 83 * We must be cautious when changing the bootloader_message struct size, 84 * because A/B-specific fields may end up with different offsets. 85 */ 86 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 87 static_assert(sizeof(struct bootloader_message) == 2048, 88 "struct bootloader_message size changes, which may break A/B devices"); 89 #endif 90 91 /** 92 * The A/B-specific bootloader message structure (4-KiB). 93 * 94 * We separate A/B boot control metadata from the regular bootloader 95 * message struct and keep it here. Everything that's A/B-specific 96 * stays after struct bootloader_message, which should be managed by 97 * the A/B-bootloader or boot control HAL. 98 * 99 * The slot_suffix field is used for A/B implementations where the 100 * bootloader does not set the androidboot.ro.boot.slot_suffix kernel 101 * commandline parameter. This is used by fs_mgr to mount /system and 102 * other partitions with the slotselect flag set in fstab. A/B 103 * implementations are free to use all 32 bytes and may store private 104 * data past the first NUL-byte in this field. It is encouraged, but 105 * not mandatory, to use 'struct bootloader_control' described below. 106 */ 107 struct bootloader_message_ab { 108 struct bootloader_message message; 109 char slot_suffix[32]; 110 111 // Round up the entire struct to 4096-byte. 112 char reserved[2016]; 113 }; 114 115 /** 116 * Be cautious about the struct size change, in case we put anything post 117 * bootloader_message_ab struct (b/29159185). 118 */ 119 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 120 static_assert(sizeof(struct bootloader_message_ab) == 4096, 121 "struct bootloader_message_ab size changes"); 122 #endif 123 124 #define BOOT_CTRL_MAGIC 0x42414342 /* Bootloader Control AB */ 125 #define BOOT_CTRL_VERSION 1 126 127 struct slot_metadata { 128 // Slot priority with 15 meaning highest priority, 1 lowest 129 // priority and 0 the slot is unbootable. 130 uint8_t priority : 4; 131 // Number of times left attempting to boot this slot. 132 uint8_t tries_remaining : 3; 133 // 1 if this slot has booted successfully, 0 otherwise. 134 uint8_t successful_boot : 1; 135 // 1 if this slot is corrupted from a dm-verity corruption, 0 136 // otherwise. 137 uint8_t verity_corrupted : 1; 138 // Reserved for further use. 139 uint8_t reserved : 7; 140 } __attribute__((packed)); 141 142 /* Bootloader Control AB 143 * 144 * This struct can be used to manage A/B metadata. It is designed to 145 * be put in the 'slot_suffix' field of the 'bootloader_message' 146 * structure described above. It is encouraged to use the 147 * 'bootloader_control' structure to store the A/B metadata, but not 148 * mandatory. 149 */ 150 struct bootloader_control { 151 // NUL terminated active slot suffix. 152 char slot_suffix[4]; 153 // Bootloader Control AB magic number (see BOOT_CTRL_MAGIC). 154 uint32_t magic; 155 // Version of struct being used (see BOOT_CTRL_VERSION). 156 uint8_t version; 157 // Number of slots being managed. 158 uint8_t nb_slot : 3; 159 // Number of times left attempting to boot recovery. 160 uint8_t recovery_tries_remaining : 3; 161 // Ensure 4-bytes alignment for slot_info field. 162 uint8_t reserved0[2]; 163 // Per-slot information. Up to 4 slots. 164 struct slot_metadata slot_info[4]; 165 // Reserved for further use. 166 uint8_t reserved1[8]; 167 // CRC32 of all 28 bytes preceding this field (little endian 168 // format). 169 uint32_t crc32_le; 170 } __attribute__((packed)); 171 172 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 173 static_assert(sizeof(struct bootloader_control) == 174 sizeof(((struct bootloader_message_ab *)0)->slot_suffix), 175 "struct bootloader_control has wrong size"); 176 #endif 177 178 #ifdef __cplusplus 179 180 #include <string> 181 #include <vector> 182 183 // Read bootloader message into boot. Error message will be set in err. 184 bool read_bootloader_message(bootloader_message* boot, std::string* err); 185 186 // Read bootloader message from the specified misc device into boot. 187 bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device, 188 std::string* err); 189 190 // Write bootloader message to BCB. 191 bool write_bootloader_message(const bootloader_message& boot, std::string* err); 192 193 // Write bootloader message to the specified BCB device. 194 bool write_bootloader_message_to(const bootloader_message& boot, 195 const std::string& misc_blk_device, std::string* err); 196 197 // Write bootloader message (boots into recovery with the options) to BCB. Will 198 // set the command and recovery fields, and reset the rest. 199 bool write_bootloader_message(const std::vector<std::string>& options, std::string* err); 200 201 // Update bootloader message (boots into recovery with the options) to BCB. Will 202 // only update the command and recovery fields. 203 bool update_bootloader_message(const std::vector<std::string>& options, std::string* err); 204 205 // Clear BCB. 206 bool clear_bootloader_message(std::string* err); 207 208 // Writes the reboot-bootloader reboot reason to the bootloader_message. 209 bool write_reboot_bootloader(std::string* err); 210 211 // Read the wipe package from BCB (from offset WIPE_PACKAGE_OFFSET_IN_MISC). 212 bool read_wipe_package(std::string* package_data, size_t size, std::string* err); 213 214 // Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC). 215 bool write_wipe_package(const std::string& package_data, std::string* err); 216 217 #else 218 219 #include <stdbool.h> 220 221 // C Interface. 222 bool write_bootloader_message(const char* options); 223 bool write_reboot_bootloader(void); 224 225 #endif // ifdef __cplusplus 226 227 #endif // _BOOTLOADER_MESSAGE_H 228
