Import include/android_bootloader_message.h from AOSP

This takes the latest changes from AOSP from the file
bootloader_message/include/bootloader_message/bootloader_message.h
in the repository
https://android.googlesource.com/platform/bootable/recovery
and re-licensed them to BSD-3 for U-Boot.

Minimum local changes have been applied (convert C++ to C comments and
adding #ifndef __UBOOT__ block to skip all the function declarations).

Signed-off-by: Alex Deymo <deymo@google.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>

1 files changed, 246 insertions, 0 deletions

diff --git a/include/android_bootloader_message.h b/include/android_bootloader_message.h
new file mode 100644
index 0000000000..b84789f022
--- /dev/null
+++ b/include/android_bootloader_message.h
@@ -0,0 +1,246 @@
+/*
+ * This is from the Android Project,
+ * Repository: https://android.googlesource.com/platform/bootable/recovery
+ * File: bootloader_message/include/bootloader_message/bootloader_message.h
+ * Commit: c784ce50e8c10eaf70e1f97e24e8324aef45faf5
+ *
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __ANDROID_BOOTLOADER_MESSAGE_H
+#define __ANDROID_BOOTLOADER_MESSAGE_H
+
+/* compiler.h defines the types that otherwise are included from stdint.h and
+ * stddef.h
+ */
+#include <compiler.h>
+
+/* 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 - 64K    Used by uncrypt and recovery to store wipe_package for A/B devices
+ * 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;
+
+/* 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 was used by the bootloader after the completion
+ * of an "update-radio" or "update-hboot" command, which has been
+ * deprecated since Froyo.
+ *
+ * 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.
+ */
+#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
+
+/**
+ * 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.
+ *
+ * The update_channel field is used to store the Omaha update channel
+ * if update_engine is compiled with Omaha support.
+ */
+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).
+ */
+#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
+static_assert(sizeof(struct bootloader_message_ab) == 4096,
+              "struct bootloader_message_ab size changes");
+#endif
+
+#define BOOT_CTRL_MAGIC   0x42414342 /* Bootloader Control AB */
+#define 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));
+
+#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
+
+#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 */