Re: [U-Boot] [RFC] cmd: add bootslot command to select/boot slot based on boot counts

Hi,

On 2018-07-13 14:34, Martin Hundebøll wrote:

The existing bootcount feature is targeted systems with a primary, and a rescue boot setup, where the number of boot tries to the primary boot is tracked. If the number exceeds the limit, the alternative/rescue is booted.

This patch adds support for a more sophisticated setup, where more than two boot slots can exist, and the order of slots can be configured.

The 'bootcommand' command reads the configured slots (and their priority/order) from a configured environment variable ("bootslots" by default). For each conifgured slot, a remaining boot count is maintained in an evnironment variable ("bootcount_<slot>" by default). If the first boot slot has positive boot count, it is booted using the slot specific boot command ("bootcmd_<slot>" by default). Otherwise the next slot is checked.

An example environment when using the bootslot command with two slots ("a" and "b"):

With RAUC bootslot's is specified with uppercase letters, uppercase is not preserved. We end up with BOOT_b_LEFT=2... botocmd_* is with lowercase, just to make things easier.

/Sean

bootslots=a b bootcount_a=3 bootcount_b=3 bootcmd_a=setenv bootargs $bootargs root=/dev/mmcblk0p1; booti $loadaddr bootcmd_b=setenv bootargs $bootargs root=/dev/mmcblk0p2; booti $loadaddr

Once linux is booted, it resets the bootcount variable for the booted slot using "fw_setenv":

...

fw_setenv bootcount_a 3

When the non-booted slot is updated, the order is updated by setting the bootslots variable with "fw_setenv":

...

fw_setenv bootslots=b a

Signed-off-by: Martin Hundebøll martin@geanix.com

Tested-by: Sean Nyekjaer sean.nyekjaer@prevas.dk

---

cmd/Kconfig | 42 +++++++++ cmd/Makefile | 1 + cmd/bootslot.c | 225 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 cmd/bootslot.c

diff --git a/cmd/Kconfig b/cmd/Kconfig index aec209006d..3919606e74 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -1277,6 +1277,48 @@ config CMD_BOOTCOUNT Enable the bootcount command, which allows interrogation and reset of the bootcounter.

+config CMD_BOOTSLOT

• bool "Enable support for multiple boot slots"
• help

•  Parses an ordered list of configured boot slot names (e.g. "a b")
  

•  and selects a corresponding boot command based on the current
  

•  boot counter for each slot.
  

+config CMD_BOOTSLOT_ENV_SLOTS

• string "Environment variable to read bootslots from"
• depends on CMD_BOOTSLOT
• default "bootslots"
• help

•  Configures the environment variable to read out when looking for a
  

•  list of available boot sloots.
  

+config CMD_BOOTSLOT_ENV_COUNT

• string "Environment variable format string to read/write slot boot count from/to"
• depends on CMD_BOOTSLOT
• default "bootcount_%s"
• help

•  Configures the prefix to use when reading the boot count for a
  

•  specific slot. The prefix is concatenated with the slot name, so
  

•  that the boot count for slot "a" is read and saved to "<prefix>a".
  

+config CMD_BOOTSLOT_ENV_CMD

• string "Environment variable format string to read slot boot command from"
• depends on CMD_BOOTSLOT
• default "bootcmd_%s"
• help

•  Configures the prefix to use when reading the boot command for
  

•  specific slot. The prefix is concatenated with the slot name, so
  

•  that the boot command for slot "a" is read from "<prefix>a".
  

+config CMD_BOOTSLOT_DEFAULT_COUNT

• int "Default boot count for each configured slot"
• depends on CMD_BOOTSLOT
• default 3
• help

•  The default number of times a slot is tried before proceeding to the
  

•  slot. The default is used when a slot has no count yet, or when it
  

•  is reset with the "bootslot reset" command.
  

• config CMD_BSP bool "Enable board-specific commands" help

diff --git a/cmd/Makefile b/cmd/Makefile index 323f1fd2c7..68c8e50c91 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_CMD_BOOTCOUNT) += bootcount.o obj-$(CONFIG_CMD_BOOTEFI) += bootefi.o obj-$(CONFIG_CMD_BOOTMENU) += bootmenu.o obj-$(CONFIG_CMD_BOOTSTAGE) += bootstage.o +obj-$(CONFIG_CMD_BOOTSLOT) += bootslot.o obj-$(CONFIG_CMD_BOOTZ) += bootz.o obj-$(CONFIG_CMD_BOOTI) += booti.o obj-$(CONFIG_CMD_BTRFS) += btrfs.o diff --git a/cmd/bootslot.c b/cmd/bootslot.c new file mode 100644 index 0000000000..03897b1f60 --- /dev/null +++ b/cmd/bootslot.c @@ -0,0 +1,225 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • Copyright (c) 2018, Geanix, All rights reserved.
• */

+#include <common.h> +#include <environment.h> +#include <stdlib.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/compat.h> +#include <vsprintf.h>

+static char *bootslot_envname(const char *fmt, const char *slot) +{

• int len = strlen(fmt) + strlen(slot);
• char *envname = malloc(len + 1);
• sprintf(envname, fmt, slot);
• return envname;

+}

+static unsigned long bootslot_get_count(const char *slot) +{

• char *envname;
• unsigned long count;
• envname = bootslot_envname(CONFIG_CMD_BOOTSLOT_ENV_COUNT, slot);
• count = env_get_ulong(envname, 10, CONFIG_CMD_BOOTSLOT_DEFAULT_COUNT);
• free(envname);
• return count;

+}

+static void bootslot_set_count(const char *slot, unsigned long count) +{

• char *envname;
• envname = bootslot_envname(CONFIG_CMD_BOOTSLOT_ENV_COUNT, slot);
• env_set_ulong(envname, count);
• free(envname);

+}

+static const char *bootslot_get_cmd(const char *slot) +{

• char *envname;
• char *cmd;
• envname = bootslot_envname(CONFIG_CMD_BOOTSLOT_ENV_CMD, slot);
• cmd = env_get(envname);
• free(envname);
• return cmd;

+}

+static char *bootslot_get_slots(int argc, char * const argv[]) +{

• char *slots = NULL;
• int len = 1; /* make room for terminating \0 */
• int i;
• /* read boot slots from environment if no args are given, or

• * duplicate the argument if a single argument is given */
  

• if (argc == 1)

• return strdup(env_get(CONFIG_CMD_BOOTSLOT_ENV_SLOTS));
  

• else if (argc == 2)

• return strdup(argv[1]);
  

• /* compute the string length of the list of slots */
• for (i = 1; i < argc; i++)

• len += strlen(argv[i]) + 1; /* add room for space separator */
  

• /* allocate the string buffer and copy each slot argument to it */
• slots = kzalloc(len, 0);
• strcpy(slots, argv[1]);
• for (i = 2; i < argc; i++) {

• strcat(slots, " ");
  

• strcat(slots, argv[i]);
  

• }
• return slots;

+}

+static int do_bootslot_list(cmd_tbl_t *cmdtp, int flag, int argc,

• 	    char * const argv[])
  

+{

• char *mem = bootslot_get_slots(argc, argv);
• char *slots = mem;
• char *slot;
• if (slots == NULL)

• return CMD_RET_USAGE;
  

• printf("slot\tcount\tbootcmd\n");
• while ((slot = strsep(&slots, " ")) != NULL) {

• unsigned long count;
  

• const char *bootcmd;
  

• if (strlen(slot) == 0)
  

• 	continue;
  

• count = bootslot_get_count(slot);
  

• bootcmd = bootslot_get_cmd(slot);
  

• if (bootcmd)
  

• 	printf("%s\t%lu\t%s\n", slot, count, bootcmd);
  

• else
  

• 	printf("%s\t%lu\t<not defined>\n", slot, count);
  

• }
• free(mem);
• return CMD_RET_SUCCESS;

+}

+static int do_bootslot_reset(cmd_tbl_t *cmdtp, int flag, int argc,

• 	    char * const argv[])
  

+{

• char *mem = bootslot_get_slots(argc, argv);
• char *slots = mem;
• char *slot;
• if (slots == NULL)

• return CMD_RET_USAGE;
  

• while ((slot = strsep(&slots, " ")) != NULL) {

• if (strlen(slot) == 0)
  

• 	continue;
  

• bootslot_set_count(slot, CONFIG_CMD_BOOTSLOT_DEFAULT_COUNT);
  

• }
• free(mem);
• return CMD_RET_SUCCESS;

+}

+static int do_bootslot_boot(cmd_tbl_t *cmdtp, int flag, int argc,

• 	    char * const argv[])
  

+{

• char *mem = bootslot_get_slots(argc, argv);
• char *slots = mem;
• char *slot;
• bool found_valid = false;
• if (slots == NULL)

• return CMD_RET_USAGE;
  

• while ((slot = strsep(&slots, " ")) != NULL) {

• const char *bootcmd;
  

• unsigned long count;
  

• if (strlen(slot) == 0)
  

• 	continue;
  

• count = bootslot_get_count(slot);
  

• if (count == 0) {
  

• 	printf("slot %s bootcount is zero; trying next...\n",
  

• 	       slot);
  

• 	continue;
  

• }
  

• bootcmd = bootslot_get_cmd(slot);
  

• if (bootcmd == NULL) {
  

• 	printf("slot %s bootcmd not found; trying next...\n",
  

• 	       slot);
  

• 	continue;
  

• }
  

• printf("slot %s has %lu boot tries remaining; booting...\n",
  

•        slot, count);
  

• found_valid = true;
  

• bootslot_set_count(slot, --count);
  

• env_save();
  

• run_command_list(bootcmd, -1, CMD_FLAG_ENV);
  

• break;
  

• }
• free(mem);
• if (found_valid == false) {

• printf("no valid bootslot found; resetting counters\n");
  

• run_command("bootslot reset", 0);
  

• return CMD_RET_FAILURE;
  

• }
• return CMD_RET_SUCCESS;

+}

+static cmd_tbl_t cmd_bootslot_sub[] = {

• U_BOOT_CMD_MKENT(boot, INT_MAX, 0, do_bootslot_boot, "", ""),
• U_BOOT_CMD_MKENT(list, INT_MAX, 1, do_bootslot_list, "", ""),
• U_BOOT_CMD_MKENT(reset, INT_MAX, 1, do_bootslot_reset, "", ""),

+};

+/*

• • Process a bootslots sub-command
• */

+static int do_bootslot(cmd_tbl_t *cmdtp, int flag, int argc,

•        char * const argv[])
  

+{

• cmd_tbl_t *c;
• /* Strip off leading 'bootslot' command argument */
• argc--;
• argv++;
• c = find_cmd_tbl(argv[0], cmd_bootslot_sub,

• 	 ARRAY_SIZE(cmd_bootslot_sub));
  

• if (c)

• return c->cmd(cmdtp, flag, argc, argv);
  

• else

• return CMD_RET_USAGE;
  

+}

+U_BOOT_CMD(bootslot, INT_MAX, 1, do_bootslot,

• "Bootslot command",
• " - select and boot slot based on counters\n"
• "boot [<slot>] - Boot the passed or first valid slot in $bootslots\n"
• "list [<slot>] - List remaining boot tries for passed or all slots in $bootslots\n"
• "reset [<slot>] - Reset remaining boot tries for all or passed slot\n"

+);