[U-Boot] [PATCH 1/2] include: android_bl_msg.h: Initial import

Eugeniu Rosca roscaeugeniu at gmail.com
Sun Apr 7 22:02:05 UTC 2019


Import the bootloader_message.h (former bootloader.h) from AOSP.

Repository: https://android.googlesource.com/platform/bootable/recovery
Commit: 8e0821e6907d6016c19565b83319aff90ad1a034
Author: Tao Bao <tbao at google.com>
Date:   Wed Apr 3 23:48:21 2019 +0000

The bootloader_message.h basically defines the flash layout of a
dedicated partition (usually called 'misc') and is needed in U-Boot
in order to be able to implement a subset of Android Bootloader
Requirements [1], specifically dealing with:
 - Communication between the bootloader and recovery
 - Handling of A/B (Seamless) System Updates [2]

With respect to the in-tree vs out-of-tree file differences:
 - license matches https://patchwork.ozlabs.org/patch/1003998/
 - filename is changed to android_bl_msg.h, as per Simon's comment [3]
 - the struct/macro names have been shaped by [3-4], where the two main
   criterias are:
   - Improve the syntax/readability in the global U-Boot namespace
   - Minimize the future integration/update efforts from the source.
     Particularly, the __UBOOT__ macro helps with isolating the
     U-Boot-unrelated parts (e.g. includes/function prototypes/etc)

[1] https://source.android.com/devices/bootloader
[2] https://source.android.com/devices/tech/ota/ab/
[3] https://patchwork.ozlabs.org/patch/1003998/#2046141
[4] https://patchwork.ozlabs.org/patch/1003998/#2144955

Signed-off-by: Eugeniu Rosca <erosca at de.adit-jv.com>
---
 include/android_bl_msg.h | 273 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 273 insertions(+)
 create mode 100644 include/android_bl_msg.h

diff --git a/include/android_bl_msg.h b/include/android_bl_msg.h
new file mode 100644
index 000000000000..c48a1de2762b
--- /dev/null
+++ b/include/android_bl_msg.h
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * This file was taken from the AOSP Project.
+ * Repository: https://android.googlesource.com/platform/bootable/recovery/
+ * File: bootloader_message/include/bootloader_message/bootloader_message.h
+ * Commit: see U-Boot commit importing/updating the file in-tree
+ *
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _BOOTLOADER_MESSAGE_H
+#define _BOOTLOADER_MESSAGE_H
+
+#ifndef __UBOOT__
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#else
+#include <compiler.h>
+#include <linux/sizes.h>
+#endif
+
+#ifdef __UBOOT__
+/* U-Boot-specific types for improved syntax/readability */
+typedef struct bootloader_message	andr_bl_msg;
+typedef struct bootloader_message_ab	andr_bl_msg_ab;
+typedef struct bootloader_control	andr_bl_control;
+#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 - 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.
+
+#ifndef __UBOOT__
+static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
+static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
+#else
+#define ANDROID_MISC_BM_OFFSET		0
+#define ANDROID_MISC_WIPE_OFFSET	SZ_16K
+#endif
+
+/* 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.
+ */
+#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
+
+/**
+ * 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).
+ */
+#ifndef __UBOOT__
+#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
+static_assert(sizeof(struct bootloader_message_ab) == 4096,
+              "struct bootloader_message_ab size changes");
+#endif
+#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));
+
+#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
+
+#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);
+
+// 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
+
+#endif  // _BOOTLOADER_MESSAGE_H
-- 
2.21.0



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