summaryrefslogtreecommitdiff
path: root/include/android_bootloader_message.h
blob: 1ef9ab227173637d89fe04e7c5772fccc2be8123 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
/*
 * This is from the Android Project,
 * Repository: https://android.googlesource.com/platform/bootable/recovery/
 * File: bootloader_message/include/bootloader_message/bootloader_message.h
 * Commit: See U-Boot commit description
 *
 * Copyright (C) 2008 The Android Open Source Project
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#ifndef __ANDROID_BOOTLOADER_MESSAGE_H
#define __ANDROID_BOOTLOADER_MESSAGE_H

#ifndef __UBOOT__
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#else
/* compiler.h defines the types that otherwise are included from stdint.h and
 * stddef.h
 */
#include <compiler.h>
#endif

// Spaces used by misc partition are as below:
// 0   - 2K     For bootloader_message
// 2K  - 16K    Used by Vendor's bootloader (the 2K - 4K range may be optionally used
//              as bootloader_message_ab struct)
// 16K - 32K    Used by uncrypt and recovery to store wipe_package for A/B devices
//  32K - 64K    System space, used for miscellaneous AOSP features (virtual A/B metadata). (Ver. Rockchip)
// Note that these offsets are admitted by bootloader,recovery and uncrypt, so they
// are not configurable without changing all of them.
static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
static const size_t VIRTUAL_AB_METADATA_OFFSET_IN_MISC = 32 * 1024;

/* 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.
 */
#ifndef __UBOOT__
#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
#endif /* __UBOOT__ */

/**
 * 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];
    char update_channel[128];

    // Round up the entire struct to 4096-byte.
    char reserved[1888];
};

/**
 * Be cautious about the struct size change, in case we put anything post
 * bootloader_message_ab struct (b/29159185).
 */
#ifndef __UBOOT__
#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
static_assert(sizeof(struct bootloader_message_ab) == 4096,
              "struct bootloader_message_ab size changes");
#endif
#endif /* __UBOOT__ */

#define ANDROID_BOOT_CTRL_MAGIC   0x42414342 /* Bootloader Control AB */
#define ANDROID_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));

#ifndef __UBOOT__
#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
#endif /* __UBOOT__ */

#ifndef __UBOOT__
#ifdef __cplusplus

#include <string>
#include <vector>

// Return the block device name for the bootloader message partition and waits
// for the device for up to 10 seconds. In case of error returns the empty
// string.
std::string get_bootloader_message_blk_device(std::string* err);

// Read bootloader message into boot. Error message will be set in err.
bool read_bootloader_message(bootloader_message* boot, std::string* err);

// Read bootloader message from the specified misc device into boot.
bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device,
                                  std::string* err);

// Write bootloader message to BCB.
bool write_bootloader_message(const bootloader_message& boot, std::string* err);

// Write bootloader message to the specified BCB device.
bool write_bootloader_message_to(const bootloader_message& boot,
                                 const std::string& misc_blk_device, std::string* err);

// Write bootloader message (boots into recovery with the options) to BCB. Will
// set the command and recovery fields, and reset the rest.
bool write_bootloader_message(const std::vector<std::string>& options, std::string* err);

// Write bootloader message (boots into recovery with the options) to the specific BCB device. Will
// set the command and recovery fields, and reset the rest.
bool write_bootloader_message_to(const std::vector<std::string>& options,
                                 const std::string& misc_blk_device, std::string* err);

// Update bootloader message (boots into recovery with the options) to BCB. Will
// only update the command and recovery fields.
bool update_bootloader_message(const std::vector<std::string>& options, std::string* err);

// Update bootloader message (boots into recovery with the |options|) in |boot|. Will only update
// the command and recovery fields.
bool update_bootloader_message_in_struct(bootloader_message* boot,
                                         const std::vector<std::string>& options);

// Clear BCB.
bool clear_bootloader_message(std::string* err);

// Writes the reboot-bootloader reboot reason to the bootloader_message.
bool write_reboot_bootloader(std::string* err);

// Read the wipe package from BCB (from offset WIPE_PACKAGE_OFFSET_IN_MISC).
bool read_wipe_package(std::string* package_data, size_t size, std::string* err);

// Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC).
bool write_wipe_package(const std::string& package_data, std::string* err);

#else

#include <stdbool.h>

// C Interface.
bool write_bootloader_message(const char* options);
bool write_reboot_bootloader(void);

#endif  // ifdef __cplusplus
#endif  /* __UBOOT__ */

#endif  /* __ANDROID_BOOTLOADER_MESSAGE_H */