include/android_bootloader_message.h

   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: c784ce50e8c10eaf70e1f97e24e8324aef45faf5
   6  *
   7  * Copyright (C) 2008 The Android Open Source Project
   8  *
   9  * SPDX-License-Identifier: BSD-3-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     For 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 - 64K    Used by uncrypt and recovery to store wipe_package for A/B devices
  25  * Note that these offsets are admitted by bootloader,recovery and uncrypt, so they
  26  * are not configurable without changing all of them. */
  27 static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
  28 static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
  29
  30 /* Bootloader Message (2-KiB)
  31  *
  32  * This structure describes the content of a block in flash
  33  * that is used for recovery and the bootloader to talk to
  34  * each other.
  35  *
  36  * The command field is updated by linux when it wants to
  37  * reboot into recovery or to update radio or bootloader firmware.
  38  * It is also updated by the bootloader when firmware update
  39  * is complete (to boot into recovery for any final cleanup)
  40  *
  41  * The status field was used by the bootloader after the completion
  42  * of an "update-radio" or "update-hboot" command, which has been
  43  * deprecated since Froyo.
  44  *
  45  * The recovery field is only written by linux and used
  46  * for the system to send a message to recovery or the
  47  * other way around.
  48  *
  49  * The stage field is written by packages which restart themselves
  50  * multiple times, so that the UI can reflect which invocation of the
  51  * package it is.  If the value is of the format "#/#" (eg, "1/3"),
  52  * the UI will add a simple indicator of that status.
  53  *
  54  * We used to have slot_suffix field for A/B boot control metadata in
  55  * this struct, which gets unintentionally cleared by recovery or
  56  * uncrypt. Move it into struct bootloader_message_ab to avoid the
  57  * issue.
  58  */
  59 struct bootloader_message {
  60     char command[32];
  61     char status[32];
  62     char recovery[768];
  63
  64     /* The 'recovery' field used to be 1024 bytes.  It has only ever
  65      * been used to store the recovery command line, so 768 bytes
  66      * should be plenty.  We carve off the last 256 bytes to store the
  67      * stage string (for multistage packages) and possible future
  68      * expansion. */
  69     char stage[32];
  70
  71     /* The 'reserved' field used to be 224 bytes when it was initially
  72      * carved off from the 1024-byte recovery field. Bump it up to
  73      * 1184-byte so that the entire bootloader_message struct rounds up
  74      * to 2048-byte. */
  75     char reserved[1184];
  76 };
  77
  78 /**
  79  * We must be cautious when changing the bootloader_message struct size,
  80  * because A/B-specific fields may end up with different offsets.
  81  */
  82 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
  83 static_assert(sizeof(struct bootloader_message) == 2048,
  84               "struct bootloader_message size changes, which may break A/B devices");
  85 #endif
  86
  87 /**
  88  * The A/B-specific bootloader message structure (4-KiB).
  89  *
  90  * We separate A/B boot control metadata from the regular bootloader
  91  * message struct and keep it here. Everything that's A/B-specific
  92  * stays after struct bootloader_message, which should be managed by
  93  * the A/B-bootloader or boot control HAL.
  94  *
  95  * The slot_suffix field is used for A/B implementations where the
  96  * bootloader does not set the androidboot.ro.boot.slot_suffix kernel
  97  * commandline parameter. This is used by fs_mgr to mount /system and
  98  * other partitions with the slotselect flag set in fstab. A/B
  99  * implementations are free to use all 32 bytes and may store private
 100  * data past the first NUL-byte in this field. It is encouraged, but
 101  * not mandatory, to use 'struct bootloader_control' described below.
 102  *
 103  * The update_channel field is used to store the Omaha update channel
 104  * if update_engine is compiled with Omaha support.
 105  */
 106 struct bootloader_message_ab {
 107     struct bootloader_message message;
 108     char slot_suffix[32];
 109     char update_channel[128];
 110
 111     /* Round up the entire struct to 4096-byte. */
 112     char reserved[1888];
 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 #ifndef __UBOOT__
 179
 180 #ifdef __cplusplus
 181
 182 #include <string>
 183 #include <vector>
 184
 185 /* Return the block device name for the bootloader message partition and waits
 186  * for the device for up to 10 seconds. In case of error returns the empty
 187  * string. */
 188 std::string get_bootloader_message_blk_device(std::string* err);
 189
 190 /* Read bootloader message into boot. Error message will be set in err. */
 191 bool read_bootloader_message(bootloader_message* boot, std::string* err);
 192
 193 /* Read bootloader message from the specified misc device into boot. */
 194 bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device,
 195                                   std::string* err);
 196
 197 /* Write bootloader message to BCB. */
 198 bool write_bootloader_message(const bootloader_message& boot, std::string* err);
 199
 200 /* Write bootloader message to the specified BCB device. */
 201 bool write_bootloader_message_to(const bootloader_message& boot,
 202                                  const std::string& misc_blk_device, std::string* err);
 203
 204 /* Write bootloader message (boots into recovery with the options) to BCB. Will
 205  * set the command and recovery fields, and reset the rest. */
 206 bool write_bootloader_message(const std::vector<std::string>& options, std::string* err);
 207
 208 /* Write bootloader message (boots into recovery with the options) to the specific BCB device. Will
 209  * set the command and recovery fields, and reset the rest. */
 210 bool write_bootloader_message_to(const std::vector<std::string>& options,
 211                                  const std::string& misc_blk_device, std::string* err);
 212
 213 /* Update bootloader message (boots into recovery with the options) to BCB. Will
 214  * only update the command and recovery fields. */
 215 bool update_bootloader_message(const std::vector<std::string>& options, std::string* err);
 216
 217 /* Update bootloader message (boots into recovery with the |options|) in |boot|. Will only update
 218  * the command and recovery fields. */
 219 bool update_bootloader_message_in_struct(bootloader_message* boot,
 220                                          const std::vector<std::string>& options);
 221
 222 /* Clear BCB. */
 223 bool clear_bootloader_message(std::string* err);
 224
 225 /* Writes the reboot-bootloader reboot reason to the bootloader_message. */
 226 bool write_reboot_bootloader(std::string* err);
 227
 228 /* Read the wipe package from BCB (from offset WIPE_PACKAGE_OFFSET_IN_MISC). */
 229 bool read_wipe_package(std::string* package_data, size_t size, std::string* err);
 230
 231 /* Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC). */
 232 bool write_wipe_package(const std::string& package_data, std::string* err);
 233
 234 #else
 235
 236 #include <stdbool.h>
 237
 238 /* C Interface. */
 239 bool write_bootloader_message(const char* options);
 240 bool write_reboot_bootloader(void);
 241
 242 #endif  /* ifdef __cplusplus */
 243
 244 #endif  /* __UBOOT__ */
 245
 246 #endif  /* __ANDROID_BOOTLOADER_MESSAGE_H */