[U-Boot] [PATCH v2] include: android_bl_msg.h: Initial import
Heinrich Schuchardt
xypron.glpk at gmx.de
Fri May 10 15:57:29 UTC 2019
On 5/10/19 3:12 PM, Sam Protsenko wrote:
> From: Eugeniu Rosca <roscaeugeniu at gmail.com>
>
> Import the bootloader_message.h (former bootloader.h) from AOSP.
>
> 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]
> - Passing the reboot reason [3]
We have a similar requirement for the UEFI sub-system.
We would need to persist a numerical reset status (type size_t) and a
UTF-16 string describing the reason for rebooting to comply with the
UEFI specification.
>
> 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 [4]
> - 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://source.android.com/devices/bootloader/boot-reason
> [4] https://patchwork.ozlabs.org/patch/1003998/#2046141
>
> Signed-off-by: Eugeniu Rosca <erosca at de.adit-jv.com>
> Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
Cc: Takahiro Akashi <takahiro.akashi at linaro.org>
Takahiro is currently looking at the implementation of UEFI secure boot
and persisting variables.
Best regards
Heinrich
> ---
> Changes in v2:
> * Remove struct typedefs, as it breaks Linux kernel style outside of
> this file, it bloats namespace (old struct names still remain in the
> namespace) and increases the delta w.r.t. AOSP file version
> * Add specific AOSP commit-id where this file was imported from
> (as per Tom's comment)
> * Update this file to the most recent version from AOSP
>
> include/android_bl_msg.h | 264 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 264 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 0000000000..7bb69ef431
> --- /dev/null
> +++ b/include/android_bl_msg.h
> @@ -0,0 +1,264 @@
> +// 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: 9423d2f6b7ef ("Merge "Track libziparchive API change."")
> + *
> + * Please keep this file with minimal changes with respect to AOSP version!
> + *
> + * 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>
> +#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.
> +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.
> + */
> +#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
> +
> +#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 // _BOOTLOADER_MESSAGE_H
>
More information about the U-Boot
mailing list