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 constexpr size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0; 32 constexpr size_t VENDOR_SPACE_OFFSET_IN_MISC = 2 * 1024; 33 constexpr size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024; 34 35 /* Bootloader Message (2-KiB) 36 * 37 * This structure describes the content of a block in flash 38 * that is used for recovery and the bootloader to talk to 39 * each other. 40 * 41 * The command field is updated by linux when it wants to 42 * reboot into recovery or to update radio or bootloader firmware. 43 * It is also updated by the bootloader when firmware update 44 * is complete (to boot into recovery for any final cleanup) 45 * 46 * The status field was used by the bootloader after the completion 47 * of an "update-radio" or "update-hboot" command, which has been 48 * deprecated since Froyo. 49 * 50 * The recovery field is only written by linux and used 51 * for the system to send a message to recovery or the 52 * other way around. 53 * 54 * The stage field is written by packages which restart themselves 55 * multiple times, so that the UI can reflect which invocation of the 56 * package it is. If the value is of the format "#/#" (eg, "1/3"), 57 * the UI will add a simple indicator of that status. 58 * 59 * We used to have slot_suffix field for A/B boot control metadata in 60 * this struct, which gets unintentionally cleared by recovery or 61 * uncrypt. Move it into struct bootloader_message_ab to avoid the 62 * issue. 63 */ 64 struct bootloader_message { 65 char command[32]; 66 char status[32]; 67 char recovery[768]; 68 69 // The 'recovery' field used to be 1024 bytes. It has only ever 70 // been used to store the recovery command line, so 768 bytes 71 // should be plenty. We carve off the last 256 bytes to store the 72 // stage string (for multistage packages) and possible future 73 // expansion. 74 char stage[32]; 75 76 // The 'reserved' field used to be 224 bytes when it was initially 77 // carved off from the 1024-byte recovery field. Bump it up to 78 // 1184-byte so that the entire bootloader_message struct rounds up 79 // to 2048-byte. 80 char reserved[1184]; 81 }; 82 83 /** 84 * We must be cautious when changing the bootloader_message struct size, 85 * because A/B-specific fields may end up with different offsets. 86 */ 87 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 88 static_assert(sizeof(struct bootloader_message) == 2048, 89 "struct bootloader_message size changes, which may break A/B devices"); 90 #endif 91 92 /** 93 * The A/B-specific bootloader message structure (4-KiB). 94 * 95 * We separate A/B boot control metadata from the regular bootloader 96 * message struct and keep it here. Everything that's A/B-specific 97 * stays after struct bootloader_message, which should be managed by 98 * the A/B-bootloader or boot control HAL. 99 * 100 * The slot_suffix field is used for A/B implementations where the 101 * bootloader does not set the androidboot.ro.boot.slot_suffix kernel 102 * commandline parameter. This is used by fs_mgr to mount /system and 103 * other partitions with the slotselect flag set in fstab. A/B 104 * implementations are free to use all 32 bytes and may store private 105 * data past the first NUL-byte in this field. It is encouraged, but 106 * not mandatory, to use 'struct bootloader_control' described below. 107 * 108 * The update_channel field is used to store the Omaha update channel 109 * if update_engine is compiled with Omaha support. 110 */ 111 struct bootloader_message_ab { 112 struct bootloader_message message; 113 char slot_suffix[32]; 114 char update_channel[128]; 115 116 // Round up the entire struct to 4096-byte. 117 char reserved[1888]; 118 }; 119 120 /** 121 * Be cautious about the struct size change, in case we put anything post 122 * bootloader_message_ab struct (b/29159185). 123 */ 124 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 125 static_assert(sizeof(struct bootloader_message_ab) == 4096, 126 "struct bootloader_message_ab size changes"); 127 #endif 128 129 #define BOOT_CTRL_MAGIC 0x42414342 /* Bootloader Control AB */ 130 #define BOOT_CTRL_VERSION 1 131 132 struct slot_metadata { 133 // Slot priority with 15 meaning highest priority, 1 lowest 134 // priority and 0 the slot is unbootable. 135 uint8_t priority : 4; 136 // Number of times left attempting to boot this slot. 137 uint8_t tries_remaining : 3; 138 // 1 if this slot has booted successfully, 0 otherwise. 139 uint8_t successful_boot : 1; 140 // 1 if this slot is corrupted from a dm-verity corruption, 0 141 // otherwise. 142 uint8_t verity_corrupted : 1; 143 // Reserved for further use. 144 uint8_t reserved : 7; 145 } __attribute__((packed)); 146 147 /* Bootloader Control AB 148 * 149 * This struct can be used to manage A/B metadata. It is designed to 150 * be put in the 'slot_suffix' field of the 'bootloader_message' 151 * structure described above. It is encouraged to use the 152 * 'bootloader_control' structure to store the A/B metadata, but not 153 * mandatory. 154 */ 155 struct bootloader_control { 156 // NUL terminated active slot suffix. 157 char slot_suffix[4]; 158 // Bootloader Control AB magic number (see BOOT_CTRL_MAGIC). 159 uint32_t magic; 160 // Version of struct being used (see BOOT_CTRL_VERSION). 161 uint8_t version; 162 // Number of slots being managed. 163 uint8_t nb_slot : 3; 164 // Number of times left attempting to boot recovery. 165 uint8_t recovery_tries_remaining : 3; 166 // Ensure 4-bytes alignment for slot_info field. 167 uint8_t reserved0[2]; 168 // Per-slot information. Up to 4 slots. 169 struct slot_metadata slot_info[4]; 170 // Reserved for further use. 171 uint8_t reserved1[8]; 172 // CRC32 of all 28 bytes preceding this field (little endian 173 // format). 174 uint32_t crc32_le; 175 } __attribute__((packed)); 176 177 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus) 178 static_assert(sizeof(struct bootloader_control) == 179 sizeof(((struct bootloader_message_ab *)0)->slot_suffix), 180 "struct bootloader_control has wrong size"); 181 #endif 182 183 #ifdef __cplusplus 184 185 #include <string> 186 #include <vector> 187 188 // Return the block device name for the bootloader message partition and waits 189 // for the device for up to 10 seconds. In case of error returns the empty 190 // string. 191 std::string get_bootloader_message_blk_device(std::string* err); 192 193 // Read bootloader message into boot. Error message will be set in err. 194 bool read_bootloader_message(bootloader_message* boot, std::string* err); 195 196 // Read bootloader message from the specified misc device into boot. 197 bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device, 198 std::string* err); 199 200 // Write bootloader message to BCB. 201 bool write_bootloader_message(const bootloader_message& boot, std::string* err); 202 203 // Write bootloader message to the specified BCB device. 204 bool write_bootloader_message_to(const bootloader_message& boot, 205 const std::string& misc_blk_device, std::string* err); 206 207 // Write bootloader message (boots into recovery with the options) to BCB. Will 208 // set the command and recovery fields, and reset the rest. 209 bool write_bootloader_message(const std::vector<std::string>& options, std::string* err); 210 211 // Update bootloader message (boots into recovery with the options) to BCB. Will 212 // only update the command and recovery fields. 213 bool update_bootloader_message(const std::vector<std::string>& options, std::string* err); 214 215 // Update bootloader message (boots into recovery with the |options|) in |boot|. Will only update 216 // the command and recovery fields. 217 bool update_bootloader_message_in_struct(bootloader_message* boot, 218 const std::vector<std::string>& options); 219 220 // Clear BCB. 221 bool clear_bootloader_message(std::string* err); 222 223 // Writes the reboot-bootloader reboot reason to the bootloader_message. 224 bool write_reboot_bootloader(std::string* err); 225 226 // Read the wipe package from BCB (from offset WIPE_PACKAGE_OFFSET_IN_MISC). 227 bool read_wipe_package(std::string* package_data, size_t size, std::string* err); 228 229 // Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC). 230 bool write_wipe_package(const std::string& package_data, std::string* err); 231 232 // Reads data from the vendor space in /misc partition, with the given offset and size. Note that 233 // offset is in relative to the start of vendor space. 234 bool ReadMiscPartitionVendorSpace(void* data, size_t size, size_t offset, std::string* err); 235 236 // Writes the given data to the vendor space in /misc partition, at the given offset. Note that 237 // offset is in relative to the start of the vendor space. 238 bool WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset, std::string* err); 239 240 #else 241 242 #include <stdbool.h> 243 244 // C Interface. 245 bool write_bootloader_message(const char* options); 246 bool write_reboot_bootloader(void); 247 248 #endif // ifdef __cplusplus 249 250 #endif // _BOOTLOADER_MESSAGE_H 251