bootcount: skip resetting bootcount if bootlimit is not set

bootcount utility started by bootcount-init script was inconditionally setting
bootcount to 0 even if the functionality is disabled.

According to documentation, bootcount functionality is only enabled if bootlimit
variable is defined to a value greater than 0 in U-Boot environment.

In platforms like cc6ul, that use MCA NVRAM to store bootcount, this was corrupting
user NVRAM.

Version increased to 1.1.

Signed-off-by: Hector Bujanda <hector.bujanda@digi.com>

meta-digi-dey/recipes-digi/bootcount/bootcount/bootcount-bin/bootcount.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023-2024 Digi International Inc.
+ * Copyright (c) 2023-2025 Digi International Inc.
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -22,7 +22,7 @@
 #include "bootcount_nvmem.h"
 #include "platform_utils.h"
 
-#define VERSION		"1.0" GIT_REVISION
+#define VERSION		"1.1" GIT_REVISION
 
 #define USAGE \
 		"Bootcount utility.\n" \
@@ -30,6 +30,9 @@
 		"\n" \
 		"Version: %s\n" \
 		"\n" \
+		"For these commands to work, bootcount function must be enabled by\n" \
+		"setting 'bootlimit' variable in U-Boot environment!!!\n" \
+		"\n" \
 		"Usage: bootcount [options] \n\n" \
 		"  -p              --print          Print the current bootcount value (Default action)\n" \
 		"  -s <value>      --set=<value>    Set current bootcount to a specific value.\n" \
@@ -155,6 +158,7 @@ static void parse_options(int argc, char *argv[]) {
  */
 int main(int argc, char *argv[]) {
 	int ret = 0;
+	int bootlimit;
 	struct platform_functions *pfuncs;
 
 	/* Read and parse command line */
@@ -169,6 +173,13 @@ int main(int argc, char *argv[]) {
 		goto end;
 	}
 
+	bootlimit = read_bootlimit_env();
+	if (bootlimit == -1 || bootlimit == 0) {
+		printf("\nBootcount functionality is disabled.\n");
+		ret = -ENOTSUP;
+		goto end;
+	}
+
 	/* Execute the requested action. */
 	if (read) {
 		ret = pfuncs->read_bootcount();

meta-digi-dey/recipes-digi/bootcount/bootcount/bootcount-bin/bootcount_env.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Digi International Inc.
+ * Copyright (c) 2023-2025, Digi International Inc.
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -22,6 +22,7 @@
 /* Environment variables. */
 #define ENV_VAR_UPGRADE_AVAILABLE	"upgrade_available"
 #define ENV_VAR_BOOTCOUNT			"bootcount"
+#define ENV_VAR_BOOTLIMIT			"bootlimit"
 
 int read_bootcount_env() {
 	int ret;
@@ -46,6 +47,29 @@ int read_bootcount_env() {
 	return ret;
 }
 
+int read_bootlimit_env() {
+	int ret = -1;
+	char* endptr;
+	const char *var;
+
+	/* Obtain 'bootlimit' value from environment. */
+	uboot_getenv(ENV_VAR_BOOTLIMIT, &var);
+	if (var != NULL) {
+		/* Convert read value to integer. */
+		ret = (int)strtoul(var, &endptr, 10);
+		if (*endptr) {
+			printf("Error: incorrect bootlimit value in environment\n");
+			ret = -1;
+		}
+	} else {
+		/* Could not read bootlimit variable from U-Boot environment */
+		ret = -1;
+	}
+
+	free((char*)var);
+	return ret;
+}
+
 int write_bootcount_env(uint count) {
 	int ret;
 	char value_str[5];

meta-digi-dey/recipes-digi/bootcount/bootcount/bootcount-bin/include/bootcount_env.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Digi International Inc.
+ * Copyright (c) 2023-2025, Digi International Inc.
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -30,6 +30,16 @@
  */
 int read_bootcount_env();
 
+/**
+ * @brief Read the 'bootlimit' variable from the U-Boot environment.
+ *
+ * This function retrieves the 'bootlimit' value from the U-Boot environment and
+ * converts it to an integer.
+ *
+ * @return The 'bootlimit' value as an integer on success, -1 on error.
+ */
+int read_bootlimit_env();
+
 /**
  * @brief Set the 'bootcount' variable in the U-Boot environment.
  *