bootcount: Add bootcount command

Add a command to manipulate the bootcounter. This is useful if you can
run device recovery from inside U-Boot and need to reset the bootcounter
after executing that process as part of altbootcmd.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>

cmd/Kconfig

@@ -1229,6 +1229,13 @@ config CMD_BMP
 	  the image into RAM, then using this command to look at it or display
 	  it.
 
+config CMD_BOOTCOUNT
+	bool "bootcount"
+	depends on BOOTCOUNT_LIMIT
+	help
+	  Enable the bootcount command, which allows interrogation and
+	  reset of the bootcounter.
+
 config CMD_BSP
 	bool "Enable board-specific commands"
 	help

cmd/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_CMD_BEDBUG) += bedbug.o
 obj-$(CONFIG_CMD_BINOP) += binop.o
 obj-$(CONFIG_CMD_BLOCK_CACHE) += blkcache.o
 obj-$(CONFIG_CMD_BMP) += bmp.o
+obj-$(CONFIG_CMD_BOOTCOUNT) += bootcount.o
 obj-$(CONFIG_CMD_BOOTEFI) += bootefi.o
 obj-$(CONFIG_CMD_BOOTMENU) += bootmenu.o
 obj-$(CONFIG_CMD_BOOTSTAGE) += bootstage.o

cmd/bootcount.c

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <common.h>
+#include <command.h>
+#include <bootcount.h>
+
+static int do_bootcount_print(cmd_tbl_t *cmdtp, int flag, int argc,
+			      char * const argv[])
+{
+	printf("%lu\n", bootcount_load());
+	return CMD_RET_SUCCESS;
+}
+
+static int do_bootcount_reset(cmd_tbl_t *cmdtp, int flag, int argc,
+			      char * const argv[])
+{
+	/*
+	 * note that we're explicitly not resetting the environment
+	 * variable, so you still have the old bootcounter available
+	 */
+	bootcount_store(0);
+	return CMD_RET_SUCCESS;
+}
+
+static cmd_tbl_t bootcount_sub[] = {
+	U_BOOT_CMD_MKENT(print, 1, 1, do_bootcount_print, "", ""),
+	U_BOOT_CMD_MKENT(reset, 1, 1, do_bootcount_reset, "", ""),
+};
+
+static int do_bootcount(cmd_tbl_t *cmdtp, int flag, int argc,
+			char * const argv[])
+{
+	cmd_tbl_t *cp;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	/* drop initial "bootcount" arg */
+	argc--;
+	argv++;
+
+	cp = find_cmd_tbl(argv[0], bootcount_sub, ARRAY_SIZE(bootcount_sub));
+	if (cp)
+		return cp->cmd(cmdtp, flag, argc, argv);
+
+	return CMD_RET_USAGE;
+}
+
+#if CONFIG_IS_ENABLED(SYS_LONGHELP)
+static char bootcount_help_text[] =
+	"print - print current bootcounter\n"
+	"reset - reset the bootcounter"
+	;
+#endif
+
+U_BOOT_CMD(bootcount, 2, 1, do_bootcount,
+	   "bootcount",
+#if CONFIG_IS_ENABLED(SYS_LONGHELP)
+	   bootcount_help_text
+#endif
+);