application: installer: added verification dealys infrastructre

Added configurable infrastructure for delay NVM memory operation.
These delay are needed for making detail testing of the instalation
interrupts possible.

Kconfig added:

* CONFIG_APP_BM_INSTALLER_SELF_DELAYS:
Enable optional installer verification delays (testing);

* CONFIG_APP_BM_INSTALLER_POST_METADATA_INVALIDATION_DELAY_MS:
Delay [ms] after metadata invalidation, before image copy;
emits LOG_INF "V_DELAY_POST_METADATA_INVALIDATION" before the delay.

* CONFIG_APP_BM_INSTALLER_INTER_IMAGE_CHUNK_COPY_DELAY_MS:
Delay [ms] between image chunk copies;
emits LOG_INF "V_DELAY_IMAGE_CHUNK_COPY" before the delay.

* CONFIG_APP_BM_INSTALLER_NEXT_IMAGE_COPY_DELAY_MS:
Delay [ms] before next image copy;
emits LOG_INF "V_DELAY_NEXT_IMAGE_COPY" before the delay.

* CONFIG_APP_BM_INSTALLER_PRIOR_METADATA_UPDATE_DELAY_MS:
Delay [ms] after image copy, before metadata update;
emits LOG_INF "V_DELAY_METADATA_UPDATE" before the delay.

* CONFIG_APP_BM_INSTALLER_PRIOR_SELF_DESTRUCTION_DELAY_MS:
Delay [ms] before clearing installer header;
emits LOG_INF "V_DELAY_SELF_DESTRUCTION" before the delay.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

Author: nvlsianpu

applications/installer/Kconfig

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2025 Nordic Semiconductor
+# Copyright (c) 2025 - 2026 Nordic Semiconductor
 #
 # SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 #
@@ -8,4 +8,43 @@ module = INSTALLER
 module-str = installer
 source "subsys/logging/Kconfig.template.log_config"
 
+menuconfig APP_BM_INSTALLER_SELF_DELAYS
+	bool "Installers verification delays [EXPERIMENTAL]"
+	select EXPERIMENTAL
+	help
+	  For testing purposes only.
+
+if APP_BM_INSTALLER_SELF_DELAYS
+
+config APP_BM_INSTALLER_POST_METADATA_INVALIDATION_DELAY_MS
+	int "Delay after metadata invalidation [ms]"
+	default 1000
+	help
+	  The delay after metadata invalidation and before images copy.
+
+config APP_BM_INSTALLER_INTER_IMAGE_CHUNK_COPY_DELAY_MS
+	int "Delay between image chunks copies [ms]"
+	default 200
+	help
+	  The delay between image chunks copies.
+
+config APP_BM_INSTALLER_NEXT_IMAGE_COPY_DELAY_MS
+	int "Delay before next image copy [ms]"
+	default 1000
+	help
+	  The delay before next image copy.
+
+config APP_BM_INSTALLER_PRIOR_METADATA_UPDATE_DELAY_MS
+	int "Delay before metadata update [ms]"
+	default 1000
+	help
+	  The delay after images copy and before metadata update.
+
+config APP_BM_INSTALLER_PRIOR_SELF_DESTRUCTION_DELAY_MS
+	int "Delay before self destruction [ms]"
+	default 1000
+	help
+	  The delay after metadata update and before self destruction.
+endif
+
 source "Kconfig.zephyr"

applications/installer/src/main.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2025 Nordic Semiconductor ASA
+ * Copyright (c) 2025 - 2026 Nordic Semiconductor
  *
  * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
  */
@@ -15,6 +15,16 @@
 
 LOG_MODULE_REGISTER(installer, CONFIG_INSTALLER_LOG_LEVEL);
 
+#if defined(CONFIG_APP_BM_INSTALLER_SELF_DELAYS)
+#define VERIFICATION_DELAY(x, msg) do { \
+	LOG_INF(msg); \
+	log_flush(); \
+	k_busy_wait((x) * USEC_PER_MSEC); \
+} while (0)
+#else
+#define VERIFICATION_DELAY(x, msg)
+#endif /* CONFIG_APP_BM_INSTALLER_SELF_DELAYS */
+
 #define IMAGE_DATA_SIZE 64
 #define IMAGE_DATA_ARRAY_SIZE 32
 #define EXPECTED_HEADER { 0x92, 0x11, 0xf2, 0xe9 }
@@ -138,6 +148,10 @@ int main(void)
 		}
 	}
 
+	/* Delay for reliability verification purpose */
+	VERIFICATION_DELAY(CONFIG_APP_BM_INSTALLER_POST_METADATA_INVALIDATION_DELAY_MS,
+			   "V_DELAY_POST_METADATA_INVALIDATION");
+
 	memset(&replacement_metadata.padding, 0xff, BM_INSTALLS_PADDING_SIZE);
 
 	while (i < CONFIG_BM_INSTALL_IMAGES) {
@@ -198,11 +212,24 @@ int main(void)
 			pos += process_size;
 			read_pos += process_size;
 			write_pos += process_size;
+
+			/* Delay for reliability verification purpose */
+			VERIFICATION_DELAY(CONFIG_APP_BM_INSTALLER_INTER_IMAGE_CHUNK_COPY_DELAY_MS,
+					   "V_DELAY_IMAGE_CHUNK_COPY");
 		}
 
 		++i;
+
+		if (i < CONFIG_BM_INSTALL_IMAGES) {
+			VERIFICATION_DELAY(CONFIG_APP_BM_INSTALLER_NEXT_IMAGE_COPY_DELAY_MS,
+					   "V_DELAY_NEXT_IMAGE_COPY");
+		}
 	}
 
+	/* Delay for reliability verification purpose */
+	VERIFICATION_DELAY(CONFIG_APP_BM_INSTALLER_PRIOR_METADATA_UPDATE_DELAY_MS,
+			   "V_DELAY_METADATA_UPDATE");
+
 	/* Write new metadata, after updating checksum */
 	replacement_metadata.checksum = crc32_ieee((const uint8_t *)&replacement_metadata,
 						   (sizeof(struct bm_installs) -
@@ -217,6 +244,11 @@ int main(void)
 
 erase_header:
 	/* Erase header of installer image to boot back into firmware loader image */
+
+	/* Delay for reliability verification purpose */
+	VERIFICATION_DELAY(CONFIG_APP_BM_INSTALLER_PRIOR_SELF_DESTRUCTION_DELAY_MS,
+			   "V_DELAY_SELF_DESTRUCTION");
+
 #if defined(CONFIG_FLASH_HAS_EXPLICIT_ERASE)
 	memset(erase_buffer, 0, sizeof(erase_buffer));
 	rc = flash_area_write(&fa_installer, 0, erase_buffer, CONFIG_ROM_START_OFFSET);
@@ -227,7 +259,7 @@ int main(void)
 	if (rc) {
 		LOG_ERR("Clear installer header failed: %d", rc);
 	} else {
-		LOG_ERR("Clear installer header OK");
+		LOG_INF("Clear installer header OK");
 	}
 
 	log_flush();