[U-Boot] [PATCH v2 4/7] cmd: Add 'ab_select' command
Ruslan Trofymenko
ruslan.trofymenko at linaro.org
Wed Dec 12 17:12:31 UTC 2018
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 '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/+/729880/2
Signed-off-by: Ruslan Trofymenko <ruslan.trofymenko at linaro.org>
Reviewed-by: Alistair Strachan <astrachan at google.com>
Reviewed-by: Sam Protsenko <semen.protsenko at linaro.org>
---
Changes in v2:
* 'android_ab_select' command is renamed to 'ab_select' command
* command is moved to the separate 'Android support commands' menu
cmd/Kconfig | 15 +++++++++++++++
cmd/Makefile | 1 +
cmd/ab_select.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 68 insertions(+)
create mode 100644 cmd/ab_select.c
diff --git a/cmd/Kconfig b/cmd/Kconfig
index ea1a325..ed60e1e 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1123,6 +1123,21 @@ config CMD_SETEXPR
endmenu
+menu "Android support commands"
+
+config CMD_AB_SELECT
+ bool "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
+
if NET
menuconfig CMD_NET
diff --git a/cmd/Makefile b/cmd/Makefile
index 4998643..1d345c1 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_AB_SELECT) += ab_select.o
obj-$(CONFIG_CMD_ADC) += adc.o
obj-$(CONFIG_CMD_ARMFLASH) += armflash.o
obj-y += blk_common.o
diff --git a/cmd/ab_select.c b/cmd/ab_select.c
new file mode 100644
index 0000000..2a9e524
--- /dev/null
+++ b/cmd/ab_select.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ */
+
+#include <android_ab.h>
+#include <command.h>
+
+static int do_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(ab_select, 4, 0, do_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"
+);
--
2.7.4
More information about the U-Boot
mailing list