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: See U-Boot commit description
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#ifndef __UBOOT__
16#include <assert.h>
17#include <stddef.h>
18#include <stdint.h>
19#else
20/* compiler.h defines the types that otherwise are included from stdint.h and
21 * stddef.h
22 */
23#include <compiler.h>
24#endif
25
26// Spaces used by misc partition are as below:
27// 0   - 2K     For bootloader_message
28// 2K  - 16K    Used by Vendor's bootloader (the 2K - 4K range may be optionally used
29//              as bootloader_message_ab struct)
30// 16K - 64K    Used by uncrypt and recovery to store wipe_package for A/B devices
31// Note that these offsets are admitted by bootloader,recovery and uncrypt, so they
32// are not configurable without changing all of them.
33static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
34static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
35
36/* Bootloader Message (2-KiB)
37 *
38 * This structure describes the content of a block in flash
39 * that is used for recovery and the bootloader to talk to
40 * each other.
41 *
42 * The command field is updated by linux when it wants to
43 * reboot into recovery or to update radio or bootloader firmware.
44 * It is also updated by the bootloader when firmware update
45 * is complete (to boot into recovery for any final cleanup)
46 *
47 * The status field was used by the bootloader after the completion
48 * of an "update-radio" or "update-hboot" command, which has been
49 * deprecated since Froyo.
50 *
51 * The recovery field is only written by linux and used
52 * for the system to send a message to recovery or the
53 * other way around.
54 *
55 * The stage field is written by packages which restart themselves
56 * multiple times, so that the UI can reflect which invocation of the
57 * package it is.  If the value is of the format "#/#" (eg, "1/3"),
58 * the UI will add a simple indicator of that status.
59 *
60 * We used to have slot_suffix field for A/B boot control metadata in
61 * this struct, which gets unintentionally cleared by recovery or
62 * uncrypt. Move it into struct bootloader_message_ab to avoid the
63 * issue.
64 */
65struct bootloader_message {
66    char command[32];
67    char status[32];
68    char recovery[768];
69
70    // The 'recovery' field used to be 1024 bytes.  It has only ever
71    // been used to store the recovery command line, so 768 bytes
72    // should be plenty.  We carve off the last 256 bytes to store the
73    // stage string (for multistage packages) and possible future
74    // expansion.
75    char stage[32];
76
77    // The 'reserved' field used to be 224 bytes when it was initially
78    // carved off from the 1024-byte recovery field. Bump it up to
79    // 1184-byte so that the entire bootloader_message struct rounds up
80    // to 2048-byte.
81    char reserved[1184];
82};
83
84/**
85 * We must be cautious when changing the bootloader_message struct size,
86 * because A/B-specific fields may end up with different offsets.
87 */
88#ifndef __UBOOT__
89#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
90static_assert(sizeof(struct bootloader_message) == 2048,
91              "struct bootloader_message size changes, which may break A/B devices");
92#endif
93#endif /* __UBOOT__ */
94
95/**
96 * The A/B-specific bootloader message structure (4-KiB).
97 *
98 * We separate A/B boot control metadata from the regular bootloader
99 * message struct and keep it here. Everything that's A/B-specific
100 * stays after struct bootloader_message, which should be managed by
101 * the A/B-bootloader or boot control HAL.
102 *
103 * The slot_suffix field is used for A/B implementations where the
104 * bootloader does not set the androidboot.ro.boot.slot_suffix kernel
105 * commandline parameter. This is used by fs_mgr to mount /system and
106 * other partitions with the slotselect flag set in fstab. A/B
107 * implementations are free to use all 32 bytes and may store private
108 * data past the first NUL-byte in this field. It is encouraged, but
109 * not mandatory, to use 'struct bootloader_control' described below.
110 *
111 * The update_channel field is used to store the Omaha update channel
112 * if update_engine is compiled with Omaha support.
113 */
114struct bootloader_message_ab {
115    struct bootloader_message message;
116    char slot_suffix[32];
117    char update_channel[128];
118
119    // Round up the entire struct to 4096-byte.
120    char reserved[1888];
121};
122
123/**
124 * Be cautious about the struct size change, in case we put anything post
125 * bootloader_message_ab struct (b/29159185).
126 */
127#ifndef __UBOOT__
128#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
129static_assert(sizeof(struct bootloader_message_ab) == 4096,
130              "struct bootloader_message_ab size changes");
131#endif
132#endif /* __UBOOT__ */
133
134#define BOOT_CTRL_MAGIC   0x42414342 /* Bootloader Control AB */
135#define BOOT_CTRL_VERSION 1
136
137struct slot_metadata {
138    // Slot priority with 15 meaning highest priority, 1 lowest
139    // priority and 0 the slot is unbootable.
140    uint8_t priority : 4;
141    // Number of times left attempting to boot this slot.
142    uint8_t tries_remaining : 3;
143    // 1 if this slot has booted successfully, 0 otherwise.
144    uint8_t successful_boot : 1;
145    // 1 if this slot is corrupted from a dm-verity corruption, 0
146    // otherwise.
147    uint8_t verity_corrupted : 1;
148    // Reserved for further use.
149    uint8_t reserved : 7;
150} __attribute__((packed));
151
152/* Bootloader Control AB
153 *
154 * This struct can be used to manage A/B metadata. It is designed to
155 * be put in the 'slot_suffix' field of the 'bootloader_message'
156 * structure described above. It is encouraged to use the
157 * 'bootloader_control' structure to store the A/B metadata, but not
158 * mandatory.
159 */
160struct bootloader_control {
161    // NUL terminated active slot suffix.
162    char slot_suffix[4];
163    // Bootloader Control AB magic number (see BOOT_CTRL_MAGIC).
164    uint32_t magic;
165    // Version of struct being used (see BOOT_CTRL_VERSION).
166    uint8_t version;
167    // Number of slots being managed.
168    uint8_t nb_slot : 3;
169    // Number of times left attempting to boot recovery.
170    uint8_t recovery_tries_remaining : 3;
171    // Ensure 4-bytes alignment for slot_info field.
172    uint8_t reserved0[2];
173    // Per-slot information.  Up to 4 slots.
174    struct slot_metadata slot_info[4];
175    // Reserved for further use.
176    uint8_t reserved1[8];
177    // CRC32 of all 28 bytes preceding this field (little endian
178    // format).
179    uint32_t crc32_le;
180} __attribute__((packed));
181
182#ifndef __UBOOT__
183#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
184static_assert(sizeof(struct bootloader_control) ==
185              sizeof(((struct bootloader_message_ab *)0)->slot_suffix),
186              "struct bootloader_control has wrong size");
187#endif
188#endif /* __UBOOT__ */
189
190#ifndef __UBOOT__
191#ifdef __cplusplus
192
193#include <string>
194#include <vector>
195
196// Return the block device name for the bootloader message partition and waits
197// for the device for up to 10 seconds. In case of error returns the empty
198// string.
199std::string get_bootloader_message_blk_device(std::string* err);
200
201// Read bootloader message into boot. Error message will be set in err.
202bool read_bootloader_message(bootloader_message* boot, std::string* err);
203
204// Read bootloader message from the specified misc device into boot.
205bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device,
206                                  std::string* err);
207
208// Write bootloader message to BCB.
209bool write_bootloader_message(const bootloader_message& boot, std::string* err);
210
211// Write bootloader message to the specified BCB device.
212bool write_bootloader_message_to(const bootloader_message& boot,
213                                 const std::string& misc_blk_device, std::string* err);
214
215// Write bootloader message (boots into recovery with the options) to BCB. Will
216// set the command and recovery fields, and reset the rest.
217bool write_bootloader_message(const std::vector<std::string>& options, std::string* err);
218
219// Write bootloader message (boots into recovery with the options) to the specific BCB device. Will
220// set the command and recovery fields, and reset the rest.
221bool write_bootloader_message_to(const std::vector<std::string>& options,
222                                 const std::string& misc_blk_device, std::string* err);
223
224// Update bootloader message (boots into recovery with the options) to BCB. Will
225// only update the command and recovery fields.
226bool update_bootloader_message(const std::vector<std::string>& options, std::string* err);
227
228// Update bootloader message (boots into recovery with the |options|) in |boot|. Will only update
229// the command and recovery fields.
230bool update_bootloader_message_in_struct(bootloader_message* boot,
231                                         const std::vector<std::string>& options);
232
233// Clear BCB.
234bool clear_bootloader_message(std::string* err);
235
236// Writes the reboot-bootloader reboot reason to the bootloader_message.
237bool write_reboot_bootloader(std::string* err);
238
239// Read the wipe package from BCB (from offset WIPE_PACKAGE_OFFSET_IN_MISC).
240bool read_wipe_package(std::string* package_data, size_t size, std::string* err);
241
242// Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC).
243bool write_wipe_package(const std::string& package_data, std::string* err);
244
245#else
246
247#include <stdbool.h>
248
249// C Interface.
250bool write_bootloader_message(const char* options);
251bool write_reboot_bootloader(void);
252
253#endif  // ifdef __cplusplus
254#endif  /* __UBOOT__ */
255
256#endif  /* __ANDROID_BOOTLOADER_MESSAGE_H */
257