This sub-command serves for getting the partition index from partition name. Also it can be used to test the existence of specified partition.

Signed-off-by: Ruslan Trofymenko ruslan.trofymenko@linaro.org --- cmd/part.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/cmd/part.c b/cmd/part.c index bfb6488..653e13c 100644 --- a/cmd/part.c +++ b/cmd/part.c @@ -24,6 +24,7 @@ enum cmd_part_info { CMD_PART_INFO_START = 0, CMD_PART_INFO_SIZE, + CMD_PART_INFO_NUMBER };

static int do_part_uuid(int argc, char * const argv[]) @@ -149,6 +150,9 @@ static int do_part_info(int argc, char * const argv[], enum cmd_part_info param) case CMD_PART_INFO_SIZE: snprintf(buf, sizeof(buf), LBAF, info.size); break; + case CMD_PART_INFO_NUMBER: + snprintf(buf, sizeof(buf), "%d", part); + break; default: printf("** Unknown cmd_part_info value: %d\n", param); return 1; @@ -172,6 +176,11 @@ static int do_part_size(int argc, char * const argv[]) return do_part_info(argc, argv, CMD_PART_INFO_SIZE); }

+static int do_part_number(int argc, char * const argv[]) +{ + return do_part_info(argc, argv, CMD_PART_INFO_NUMBER); +} + static int do_part(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { if (argc < 2) @@ -185,6 +194,8 @@ static int do_part(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) return do_part_start(argc - 2, argv + 2); else if (!strcmp(argv[1], "size")) return do_part_size(argc - 2, argv + 2); + else if (!strcmp(argv[1], "number")) + return do_part_number(argc - 2, argv + 2);

return CMD_RET_USAGE; } @@ -206,5 +217,8 @@ U_BOOT_CMD( " part can be either partition number or partition name\n" "part size <interface> <dev> <part> <varname>\n" " - set environment variable to the size of the partition (in blocks)\n" - " part can be either partition number or partition name" + " part can be either partition number or partition name\n" + "part number <interface> <dev> <part> <varname>\n" + " - set environment variable to the partition number using the partition name\n" + " part must be specified as partition name" );

This patch adds part_get_info_by_dev_and_name_or_num() function which allows us to get partition info from its number or name. Partition of interest is specified by string like "device_num:partition_number" or "device_num#partition_name".

The patch was extracted from [1].

[1] https://android-review.googlesource.com/c/platform/external/u-boot/+/729880/...

Signed-off-by: Ruslan Trofymenko ruslan.trofymenko@linaro.org --- disk/part.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/part.h | 21 ++++++++++++++++++ 2 files changed, 89 insertions(+)

diff --git a/disk/part.c b/disk/part.c index f30f9e9..ad4239d 100644 --- a/disk/part.c +++ b/disk/part.c @@ -675,6 +675,74 @@ int part_get_info_by_name(struct blk_desc *dev_desc, const char *name, return part_get_info_by_name_type(dev_desc, name, info, PART_TYPE_ALL); }

+/** + * Get partition info from device number and partition name. + * + * Parse a device number and partition name string in the form of + * "device_num#partition_name", for example "0#misc". If the partition + * is found, sets dev_desc and part_info accordingly with the information + * of the partition with the given partition_name. + * + * @param[in] dev_iface Device interface + * @param[in] dev_part_str Input string argument, like "0#misc" + * @param[out] dev_desc Place to store the device description pointer + * @param[out] part_info Place to store the partition information + * @return 0 on success, or -1 on error + */ +static int part_get_info_by_dev_and_name(const char *dev_iface, + const char *dev_part_str, + struct blk_desc **dev_desc, + disk_partition_t *part_info) +{ + char *ep; + const char *part_str; + int dev_num; + + part_str = strchr(dev_part_str, '#'); + if (!part_str || part_str == dev_part_str) + return -1; + + dev_num = simple_strtoul(dev_part_str, &ep, 16); + if (ep != part_str) { + /* Not all the first part before the # was parsed. */ + return -1; + } + part_str++; + + *dev_desc = blk_get_dev(dev_iface, dev_num); + if (!*dev_desc) { + printf("Could not find %s %d\n", dev_iface, dev_num); + return -1; + } + if (part_get_info_by_name(*dev_desc, part_str, part_info) < 0) { + printf("Could not find "%s" partition\n", part_str); + return -1; + } + return 0; +} + +int part_get_info_by_dev_and_name_or_num(const char *dev_iface, + const char *dev_part_str, + struct blk_desc **dev_desc, + disk_partition_t *part_info) +{ + /* Split the part_name if passed as "$dev_num#part_name". */ + if (!part_get_info_by_dev_and_name(dev_iface, dev_part_str, + dev_desc, part_info)) + return 0; + /* + * Couldn't lookup by name, try looking up the partition description + * directly. + */ + if (blk_get_device_part_str(dev_iface, dev_part_str, + dev_desc, part_info, 1) < 0) { + printf("Couldn't find partition %s %s\n", + dev_iface, dev_part_str); + return -1; + } + return 0; +} + void part_set_generic_name(const struct blk_desc *dev_desc, int part_num, char *name) { diff --git a/include/part.h b/include/part.h index 0750aee..331b3d5 100644 --- a/include/part.h +++ b/include/part.h @@ -202,6 +202,27 @@ int part_get_info_by_name(struct blk_desc *dev_desc, const char *name, disk_partition_t *info);

/** + * Get partition info from dev number + part name, or dev number + part number. + * + * Parse a device number and partition description (either name or number) + * in the form of device number plus partition name separated by a "#" + * (like "device_num#partition_name") or a device number plus a partition number + * separated by a ":". For example both "0#misc" and "0:1" can be valid + * partition descriptions for a given interface. If the partition is found, sets + * dev_desc and part_info accordingly with the information of the partition. + * + * @param[in] dev_iface Device interface + * @param[in] dev_part_str Input partition description, like "0#misc" or "0:1" + * @param[out] dev_desc Place to store the device description pointer + * @param[out] part_info Place to store the partition information + * @return 0 on success, or -1 on error + */ +int part_get_info_by_dev_and_name_or_num(const char *dev_iface, + const char *dev_part_str, + struct blk_desc **dev_desc, + disk_partition_t *part_info); + +/** * part_set_generic_name() - create generic partition like hda1 or sdb2 * * Helper function for partition tables, which don't hold partition names

This patch determines the A/B-specific bootloader message structure that is the basis for implementation of recovery and A/B update functions. A/B metadata is stored in this structure and used to decide which slot should we use to boot the device. Also some basic functions for A/B metadata manipulation are implemented (like slot selection).

The patch was extracted from commits [1], [2] with some coding style fixes.

[1] https://android-review.googlesource.com/c/platform/external/u-boot/+/729878/... [2] https://android-review.googlesource.com/c/platform/external/u-boot/+/729880/...

Signed-off-by: Ruslan Trofymenko ruslan.trofymenko@linaro.org --- common/Kconfig | 10 ++ common/Makefile | 1 + common/android_ab.c | 278 +++++++++++++++++++++++++++++++++++ include/android_ab.h | 34 +++++ include/android_bootloader_message.h | 164 +++++++++++++++++++++ 5 files changed, 487 insertions(+) create mode 100644 common/android_ab.c create mode 100644 include/android_ab.h create mode 100644 include/android_bootloader_message.h

diff --git a/common/Kconfig b/common/Kconfig index 57bd16d..0ff4679 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -748,6 +748,16 @@ config UPDATE_TFTP_MSEC_MAX default 100 depends on UPDATE_TFTP

+config ANDROID_AB + bool "Android A/B updates" + default n + help + If enabled, adds support for the new Android A/B update model. This + allows the bootloader to select which slot to boot from based on the + information provided by userspace via the Android boot_ctrl HAL. This + allows a bootloader to try a new version of the system but roll back + to previous version if the new one didn't boot all the way. + endmenu

menu "Blob list" diff --git a/common/Makefile b/common/Makefile index 88079d1..a1a252c 100644 --- a/common/Makefile +++ b/common/Makefile @@ -104,6 +104,7 @@ endif endif

obj-y += image.o +obj-$(CONFIG_ANDROID_AB) += android_ab.o obj-$(CONFIG_ANDROID_BOOT_IMAGE) += image-android.o obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o obj-$(CONFIG_$(SPL_TPL_)FIT) += image-fit.o diff --git a/common/android_ab.c b/common/android_ab.c new file mode 100644 index 0000000..25daba7 --- /dev/null +++ b/common/android_ab.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: BSD-2-Clause +/* + * Copyright (C) 2017 The Android Open Source Project + */ + +#include <android_ab.h> + +#include <android_bootloader_message.h> +#include <common.h> +#include <memalign.h> +#include <u-boot/crc.h> + +/** + * Compute the CRC-32 of the bootloader control struct. + * + * Only the bytes up to the crc32_le field are considered for the CRC-32 + * calculation. + */ +static uint32_t ab_control_compute_crc(struct android_bootloader_control *abc) +{ + return crc32(0, (void *)abc, offsetof(typeof(*abc), crc32_le)); +} + +/** + * Initialize android_bootloader_control to the default value. + * + * It allows us to boot all slots in order from the first one. This value + * should be used when the bootloader message is corrupted, but not when + * a valid message indicates that all slots are unbootable. + */ +static void ab_control_default(struct android_bootloader_control *abc) +{ + int i; + const struct android_slot_metadata metadata = { + .priority = 15, + .tries_remaining = 7, + .successful_boot = 0, + .verity_corrupted = 0, + .reserved = 0 + }; + + memcpy(abc->slot_suffix, "a\0\0\0", 4); + abc->magic = ANDROID_BOOT_CTRL_MAGIC; + abc->version = ANDROID_BOOT_CTRL_VERSION; + abc->nb_slot = ANDROID_NUM_SLOTS; + memset(abc->reserved0, 0, sizeof(abc->reserved0)); + for (i = 0; i < abc->nb_slot; ++i) + abc->slot_info[i] = metadata; + + memset(abc->reserved1, 0, sizeof(abc->reserved1)); + abc->crc32_le = ab_control_compute_crc(abc); +} + +/** + * Load the boot_control struct from disk into newly allocated memory. + * + * This function allocates and returns an integer number of disk blocks, + * based on the block size of the passed device to help performing a + * read-modify-write operation on the boot_control struct. + * The boot_control struct offset (2 KiB) must be a multiple of the device + * block size, for simplicity. + * + * @param[in] dev_desc Device where to read the boot_control struct from + * @param[in] part_info Partition in 'dev_desc' where to read from, normally + * the "misc" partition should be used + * @return boot_control loaded from disk or NULL on error + */ +static struct android_bootloader_control *ab_control_create_from_disk( + struct blk_desc *dev_desc, const disk_partition_t *part_info) +{ + ulong abc_offset, abc_blocks; + struct android_bootloader_control *abc; + + abc_offset = offsetof(struct android_bootloader_message_ab, + slot_suffix); + if (abc_offset % part_info->blksz) { + printf("ANDROID: Boot control block not block aligned.\n"); + return NULL; + } + abc_offset /= part_info->blksz; + + abc_blocks = DIV_ROUND_UP(sizeof(struct android_bootloader_control), + part_info->blksz); + if (abc_offset + abc_blocks > part_info->size) { + printf("ANDROID: boot control partition too small. Need at"); + printf(" least %lu blocks but have %lu blocks.\n", + abc_offset + abc_blocks, part_info->size); + return NULL; + } + abc = malloc_cache_aligned(abc_blocks * part_info->blksz); + if (!abc) + return NULL; + + if (blk_dread(dev_desc, part_info->start + abc_offset, abc_blocks, + abc) != abc_blocks) { + printf("ANDROID: Could not read from boot control partition\n"); + free(abc); + return NULL; + } + debug("ANDROID: Loaded ABC, %lu blocks.\n", abc_blocks); + return abc; +} + +/** + * Store the loaded boot_control block. + * + * Store back to the same location it was read from with + * ab_control_create_from_misc(). + * + * @param[in] abc Pointer to the boot_control struct and the extra bytes after + * it up to the nearest block boundary + * @param[in] dev_desc Device where we should write the boot_control struct + * @param[in] part_info Partition on the 'dev_desc' where to write + * @return 0 on success and -1 on error + */ +static int ab_control_store(struct android_bootloader_control *abc, + struct blk_desc *dev_desc, + const disk_partition_t *part_info) +{ + ulong abc_offset, abc_blocks; + + abc_offset = offsetof(struct android_bootloader_message_ab, + slot_suffix) / part_info->blksz; + abc_blocks = DIV_ROUND_UP(sizeof(struct android_bootloader_control), + part_info->blksz); + if (blk_dwrite(dev_desc, part_info->start + abc_offset, abc_blocks, + abc) != abc_blocks) { + printf("ANDROID: Could not write back the misc partition\n"); + return -1; + } + return 0; +} + +/** + * Compare two slots. + * + * The function determines slot which is should we boot from among the two. + * + * @param[in] a The first bootable slot metadata + * @param[in] b The second bootable slot metadata + * @return Negative if the slot "a" is better, positive of the slot "b" is + * better or 0 if they are equally good. + */ +static int ab_compare_slots(const struct android_slot_metadata *a, + const struct android_slot_metadata *b) +{ + /* Higher priority is better */ + if (a->priority != b->priority) + return b->priority - a->priority; + + /* Higher successful_boot value is better, in case of same priority */ + if (a->successful_boot != b->successful_boot) + return b->successful_boot - a->successful_boot; + + /* Higher tries_remaining is better to ensure round-robin */ + if (a->tries_remaining != b->tries_remaining) + return b->tries_remaining - a->tries_remaining; + + return 0; +} + +int ab_select_slot(struct blk_desc *dev_desc, disk_partition_t *part_info) +{ + struct android_bootloader_control *abc; + u32 crc32_le; + int slot, i; + bool store_needed = false; + char slot_suffix[4]; + + abc = ab_control_create_from_disk(dev_desc, part_info); + if (!abc) { + /* + * This condition represents an actual problem with the code or + * the board setup, like an invalid partition information. + * Signal a repair mode and do not try to boot from either slot. + */ + return -1; + } + + crc32_le = ab_control_compute_crc(abc); + if (abc->crc32_le != crc32_le) { + printf("ANDROID: Invalid CRC-32 (expected %.8x, found %.8x), ", + crc32_le, abc->crc32_le); + printf("re-initializing A/B metadata.\n"); + ab_control_default(abc); + store_needed = true; + } + + if (abc->magic != ANDROID_BOOT_CTRL_MAGIC) { + printf("ANDROID: Unknown A/B metadata: %.8x\n", abc->magic); + free(abc); + return -1; + } + + if (abc->version > ANDROID_BOOT_CTRL_VERSION) { + printf("ANDROID: Unsupported A/B metadata version: %.8x\n", + abc->version); + free(abc); + return -1; + } + + /* + * At this point a valid boot control metadata is stored in abc, + * followed by other reserved data in the same block. We select a with + * the higher priority slot that + * - is not marked as corrupted and + * - either has tries_remaining > 0 or successful_boot is true. + * If the selected slot has a false successful_boot, we also decrement + * the tries_remaining until it eventually becomes unbootable because + * tries_remaining reaches 0. This mechanism produces a bootloader + * induced rollback, typically right after a failed update. + */ + + /* Safety check: limit the number of slots. */ + if (abc->nb_slot > ARRAY_SIZE(abc->slot_info)) { + abc->nb_slot = ARRAY_SIZE(abc->slot_info); + store_needed = true; + } + + slot = -1; + for (i = 0; i < abc->nb_slot; ++i) { + if (abc->slot_info[i].verity_corrupted || + !abc->slot_info[i].tries_remaining) { + debug("ANDROID: unbootable slot %d tries: %d, ", + i, abc->slot_info[i].tries_remaining); + debug("corrupt: %d\n", + abc->slot_info[i].verity_corrupted); + continue; + } + debug("ANDROID: bootable slot %d pri: %d, tries: %d, ", + i, abc->slot_info[i].priority, + abc->slot_info[i].tries_remaining); + debug("corrupt: %d, successful: %d\n", + abc->slot_info[i].verity_corrupted, + abc->slot_info[i].successful_boot); + + if (slot < 0 || + ab_compare_slots(&abc->slot_info[i], + &abc->slot_info[slot]) < 0) { + slot = i; + } + } + + if (slot >= 0 && !abc->slot_info[slot].successful_boot) { + printf("ANDROID: Attempting slot %c, tries remaining %d\n", + ANDROID_BOOT_SLOT_NAME(slot), + abc->slot_info[slot].tries_remaining); + abc->slot_info[slot].tries_remaining--; + store_needed = true; + } + + if (slot >= 0) { + /* + * Legacy user-space requires this field to be set in the BCB. + * Newer releases load this slot suffix from the command line + * or the device tree. + */ + memset(slot_suffix, 0, sizeof(slot_suffix)); + slot_suffix[0] = ANDROID_BOOT_SLOT_NAME(slot); + if (memcmp(abc->slot_suffix, slot_suffix, + sizeof(slot_suffix))) { + memcpy(abc->slot_suffix, slot_suffix, + sizeof(slot_suffix)); + store_needed = true; + } + } + + if (store_needed) { + abc->crc32_le = ab_control_compute_crc(abc); + ab_control_store(abc, dev_desc, part_info); + } + free(abc); + + if (slot < 0) + return -1; + + return slot; +} diff --git a/include/android_ab.h b/include/android_ab.h new file mode 100644 index 0000000..53f6dc6 --- /dev/null +++ b/include/android_ab.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2017 The Android Open Source Project + */ + +#ifndef __ANDROID_AB_H +#define __ANDROID_AB_H + +#include <common.h> + +/* Android standard boot slot names are 'a', 'b', 'c', ... */ +#define ANDROID_BOOT_SLOT_NAME(slot_num) ('a' + (slot_num)) + +/* Number of slots */ +#define ANDROID_NUM_SLOTS 2 + +/** + * Select the slot where to boot from. + * + * On Android devices with more than one boot slot (multiple copies of the + * kernel and system images) selects which slot should be used to boot from and + * registers the boot attempt. This is used in by the new A/B update model where + * one slot is updated in the background while running from the other slot. If + * the selected slot did not successfully boot in the past, a boot attempt is + * registered before returning from this function so it isn't selected + * indefinitely. + * + * @param[in] dev_desc Place to store the device description pointer + * @param[in] part_info Place to store the partition information + * @return The slot number (>= 0) on success, or -1 on error + */ +int ab_select_slot(struct blk_desc *dev_desc, disk_partition_t *part_info); + +#endif /* __ANDROID_AB_H */ diff --git a/include/android_bootloader_message.h b/include/android_bootloader_message.h new file mode 100644 index 0000000..1f19273 --- /dev/null +++ b/include/android_bootloader_message.h @@ -0,0 +1,164 @@ +/* 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: 8b309f6970ab3b7c53cc529c51a2cb44e1c7a7e1 + * + * Copyright (C) 2008 The Android Open Source Project + */ + +#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 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 ANDROID_BOOTLOADER_MESSAGE_OFFSET_IN_MISC; +static const size_t ANDROID_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 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 android_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]; +}; + +/* + * 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 android_bootloader_message_ab { + struct android_bootloader_message message; + char slot_suffix[32]; + + /* Round up the entire struct to 4096-byte */ + char reserved[2016]; +}; + +#define ANDROID_BOOT_CTRL_MAGIC 0x42414342 /* Bootloader Control AB */ +#define ANDROID_BOOT_CTRL_VERSION 1 + +struct android_slot_metadata { + /* + * Slot priority with 15 meaning highest priority, 1 lowest + * priority and 0 the slot is unbootable + */ + u8 priority : 4; + /* Number of times left attempting to boot this slot */ + u8 tries_remaining : 3; + /* 1 if this slot has booted successfully, 0 otherwise */ + u8 successful_boot : 1; + /* + * 1 if this slot is corrupted from a dm-verity corruption, + * 0 otherwise + */ + u8 verity_corrupted : 1; + /* Reserved for further use */ + u8 reserved : 7; +} __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 android_bootloader_control { + /* NULL terminated active slot suffix */ + char slot_suffix[4]; + /* Bootloader Control AB magic number (see BOOT_CTRL_MAGIC) */ + u32 magic; + /* Version of struct being used (see BOOT_CTRL_VERSION) */ + u8 version; + /* Number of slots being managed */ + u8 nb_slot : 3; + /* Number of times left attempting to boot recovery */ + u8 recovery_tries_remaining : 3; + /* Ensure 4-bytes alignment for slot_info field */ + u8 reserved0[2]; + /* Per-slot information. Up to 4 slots */ + struct android_slot_metadata slot_info[4]; + /* Reserved for further use */ + u8 reserved1[8]; + /* + * CRC32 of all 28 bytes preceding this field (little endian + * format) + */ + u32 crc32_le; +} __packed; + +#endif /* __ANDROID_BOOTLOADER_MESSAGE_H */

For A/B system update support the Android boot process requires to send 'androidboot.slot_suffix' parameter as a command line argument. This patch implementes 'android_ab_select' command which allows us to obtain current slot by processing the A/B metadata.

The patch was extracted from commit [1] with one modification: the separator for specifying the name of metadata partition was changed from ';' to '#', because ';' is used for commands separation.

[1] https://android-review.googlesource.com/c/platform/external/u-boot/+/729880/...

Signed-off-by: Ruslan Trofymenko ruslan.trofymenko@linaro.org --- cmd/Kconfig | 11 ++++++++++ cmd/Makefile | 1 + cmd/android_ab_select.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 65 insertions(+) create mode 100644 cmd/android_ab_select.c

diff --git a/cmd/Kconfig b/cmd/Kconfig index e2973b3..e96a5e4 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -1476,6 +1476,17 @@ config CMD_UUID The two commands are very similar except for the endianness of the output.

+config CMD_ANDROID_AB_SELECT + bool "android_ab_select" + default n + depends on ANDROID_AB + help + On Android devices with more than one boot slot (multiple copies of + the kernel and system images) this provides a command to select which + slot should be used to boot from and register the boot attempt. This + is used by the new A/B update model where one slot is updated in the + background while running from the other slot. + endmenu

source "cmd/ti/Kconfig" diff --git a/cmd/Makefile b/cmd/Makefile index 5ec2f9e..23a78c0 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -12,6 +12,7 @@ obj-y += version.o

# command obj-$(CONFIG_CMD_AES) += aes.o +obj-$(CONFIG_CMD_ANDROID_AB_SELECT) += android_ab_select.o obj-$(CONFIG_CMD_ADC) += adc.o obj-$(CONFIG_CMD_ARMFLASH) += armflash.o obj-y += blk_common.o diff --git a/cmd/android_ab_select.c b/cmd/android_ab_select.c new file mode 100644 index 0000000..7966361 --- /dev/null +++ b/cmd/android_ab_select.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: BSD-2-Clause +/* + * Copyright (C) 2017 The Android Open Source Project + */ + +#include <android_ab.h> +#include <command.h> + +static int do_android_ab_select(cmd_tbl_t *cmdtp, int flag, int argc, + char * const argv[]) +{ + int ret; + struct blk_desc *dev_desc; + disk_partition_t part_info; + char slot[2]; + + if (argc != 4) + return CMD_RET_USAGE; + + /* Lookup the "misc" partition from argv[2] and argv[3] */ + if (part_get_info_by_dev_and_name_or_num(argv[2], argv[3], + &dev_desc, &part_info) < 0) { + return CMD_RET_FAILURE; + } + + ret = ab_select_slot(dev_desc, &part_info); + if (ret < 0) { + printf("Android boot failed, error %d.\n", ret); + return CMD_RET_FAILURE; + } + + /* Android standard slot names are 'a', 'b', ... */ + slot[0] = ANDROID_BOOT_SLOT_NAME(ret); + slot[1] = '\0'; + env_set(argv[1], slot); + printf("ANDROID: Booting slot: %s\n", slot); + return CMD_RET_SUCCESS; +} + +U_BOOT_CMD(android_ab_select, 4, 0, do_android_ab_select, + "Select the slot used to boot from and register the boot attempt.", + "<slot_var_name> <interface> <dev[:part|#part_name]>\n" + " - Load the slot metadata from the partition 'part' on\n" + " device type 'interface' instance 'dev' and store the active\n" + " slot in the 'slot_var_name' variable. This also updates the\n" + " Android slot metadata with a boot attempt, which can cause\n" + " successive calls to this function to return a different result\n" + " if the returned slot runs out of boot attempts.\n" + " - If 'part_name' is passed, preceded with a # instead of :, the\n" + " partition name whose label is 'part_name' will be looked up in\n" + " the partition table. This is commonly the "misc" partition.\n" +); +