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" +); +