NCSDK-35479: Preserve boot request values during reboot

modules/mcuboot/Kconfig

@@ -76,9 +76,13 @@ config MCUBOOT_USE_ALL_AVAILABLE_RAM
 
 endmenu
 
+DT_CHOSEN_BOOTLOADER_REQUEST := nrf,bootloader-request
+DT_CHOSEN_BOOTLOADER_REQUEST_BACKUP := nrf,bootloader-request-backup
+
 config NRF_MCUBOOT_BOOT_REQUEST
 	bool "MCUboot bootloader requests"
 	imply MCUMGR_GRP_IMG_NRF
+	depends on $(dt_chosen_enabled,$(DT_CHOSEN_BOOTLOADER_REQUEST))
 	help
 	  Handle bootloader requests.
 
@@ -88,12 +92,10 @@ choice NRF_MCUBOOT_BOOT_REQUEST_IMPL
 	prompt "Shared memory backend"
 	default NRF_MCUBOOT_BOOT_REQUEST_IMPL_RETENTION if RETENTION
 
-DT_CHOSEN_BOOTLOADER_REQUEST := nrf,bootloader-request
-
 config NRF_MCUBOOT_BOOT_REQUEST_IMPL_RETENTION
 	bool "Retention"
 	depends on RETENTION
-	depends on $(dt_chosen_enabled,$(DT_CHOSEN_BOOTLOADER_REQUEST))
+	depends on $(dt_chosen_has_compat,$(DT_CHOSEN_BOOTLOADER_REQUEST),$(DT_COMPAT_ZEPHYR_RETENTION))
 	help
 	  Use zephyr,bootloader-request chosen node compatible with the
 	  zephyr,retention driver as the memory area to store and read from the
@@ -102,8 +104,30 @@ config NRF_MCUBOOT_BOOT_REQUEST_IMPL_RETENTION
 	  structure version to ensure compatibility between the bootloader and
 	  the application.
 
+config NRF_MCUBOOT_BOOT_REQUEST_IMPL_FLASH
+	bool "NVM partition"
+	depends on FLASH
+	depends on CRC
+	depends on !PARTITION_MANAGER_ENABLED # Partition manager uses an incompatible flash_map.h
+	help
+	  Use zephyr,bootloader-request chosen node compatible with the
+	  flash driver as the memory area to store and read from the bootloader
+	  requests.
+
 endchoice
 
+config NRF_MCUBOOT_BOOT_REQUEST_PREFERENCE_KEEP
+	bool "Keep boot preference value across reboots"
+	depends on $(dt_chosen_enabled,$(DT_CHOSEN_BOOTLOADER_REQUEST_BACKUP))
+	default y
+	help
+	  Use zephyr,bootloader-request-backup chosen node compatible with the
+	  zephyr,retention driver as the memory area to store a copy of
+	  bootloader requests.
+	  If this optional node is defined, the module will keep a copy of data
+	  inside a backup region, allowing to preserve the preferred slot
+	  selection across device resets.
+
 config NCS_MCUBOOT_BOOT_REQUEST_TEST_SETS_BOOT_PREFERENCE
 	bool "Set boot preference if a slot is marked for test"
 	help

samples/dfu/ab/Kconfig.sysbuild

@@ -0,0 +1,21 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+if SOC_SERIES_NRF54HX
+
+# Enable radiocore
+config NRF_DEFAULT_IPC_RADIO
+	default y
+
+config NETCORE_IPC_RADIO_BT_HCI_IPC
+	default y
+
+config MCUBOOT_IMAGES_ROM_END_OFFSET_AUTO
+	default "ipc_radio;ipc_radio_secondary_app"
+
+endif # SOC_SERIES_NRF54HX
+
+source "share/sysbuild/Kconfig"

samples/dfu/ab/README.rst

@@ -60,7 +60,9 @@ The following conditions decide which slot will be booted (active) on the next r
 #. If none of the above conditions is met, slot A is selected as active.
 
 You can set the preferred slot using the ``boot_request_set_preferred_slot`` function.
-Currently, this only sets the boot preference for a single reboot.
+If the :kconfig:option:`CONFIG_NRF_MCUBOOT_BOOT_REQUEST_PREFERENCE_KEEP` option is enabled, the slot preference remains persistent across reboots.
+Otherwise, the slot preference is cleared on reboot.
+To enable the persistence of a preferred slot, define a backup region for the bootloader request area by using the ``nrf,bootloader-request-backup`` chosen node in the devicetree.
 
 Identifying the active slot
 ---------------------------

samples/dfu/ab/boards/nrf54l15dk_nrf54l15_cpuapp.conf

@@ -0,0 +1,3 @@
+# Enable boot requests through retained memory.
+CONFIG_RETAINED_MEM=y
+CONFIG_RETENTION=y

samples/dfu/ab/prj.conf

@@ -41,14 +41,9 @@ CONFIG_MCUBOOT_UTIL_LOG_LEVEL_WRN=y
 # Disable debug logging
 CONFIG_LOG_MAX_LEVEL=3
 
-# Enable boot requests through retained memory.
-CONFIG_RETAINED_MEM=y
-CONFIG_RETENTION=y
+# Enable boot requests.
 CONFIG_NRF_MCUBOOT_BOOT_REQUEST=y
 
-CONFIG_RETENTION_BOOT_MODE=y
-CONFIG_MCUMGR_GRP_OS_RESET_BOOT_MODE=y
-
 # Enable DK LED/button library
 CONFIG_DK_LIBRARY=y
 

samples/dfu/ab/src/ab_utils.c

@@ -58,12 +58,6 @@ LOG_MODULE_DECLARE(ab_sample);
 #define STATUS_LEDS_THREAD_PRIORITY (CONFIG_NUM_PREEMPT_PRIORITIES - 1)
 K_THREAD_STACK_DEFINE(status_leds_thread_stack_area, STATUS_LEDS_THREAD_STACK_SIZE);
 
-enum ab_boot_slot {
-	SLOT_A = 0,
-	SLOT_B = 1,
-	SLOT_INVALID,
-};
-
 /** @brief Radio firmware self test
  *
  * @details
@@ -91,41 +85,79 @@ static bool app_domain_healthy(void)
 	return true;
 }
 
-static enum ab_boot_slot active_boot_slot_get(void)
+static enum boot_slot active_boot_slot_get(void)
 {
-	enum ab_boot_slot active_slot = SLOT_INVALID;
+	enum boot_slot active_slot = BOOT_SLOT_NONE;
 
 	if (IS_SLOT_A) {
-		active_slot = SLOT_A;
+		active_slot = BOOT_SLOT_PRIMARY;
 	} else if (IS_SLOT_B) {
-		active_slot = SLOT_B;
+		active_slot = BOOT_SLOT_SECONDARY;
 	} else {
 		LOG_ERR("Cannot determine current slot");
 	}
 
 	return active_slot;
 }
 
-static void device_healthcheck(void)
+static bool slot_confirmed(enum boot_slot slot)
 {
-	int err;
-	char *img_set = NULL;
+	struct boot_swap_state state;
 	const struct flash_area *fa;
 	int area_id = -1;
-	enum ab_boot_slot active_slot = active_boot_slot_get();
-
-	if (active_slot == SLOT_INVALID) {
-		return;
-	}
+	char *img_set = NULL;
+	bool confirmed = false;
+	int ret;
 
-	/* Confirming only in non-degraded boot states
-	 */
-	if (active_slot == SLOT_A) {
+	if (slot == BOOT_SLOT_PRIMARY) {
 		img_set = "A";
 		area_id = SLOT_A_FLASH_AREA_ID;
-	} else if (active_slot == SLOT_B) {
+	} else if (slot == BOOT_SLOT_SECONDARY) {
 		img_set = "B";
 		area_id = SLOT_B_FLASH_AREA_ID;
+	} else {
+		LOG_ERR("Cannot determine slot to check for confirmation");
+		return false;
+	}
+
+	if (flash_area_open(area_id, &fa) != 0) {
+		LOG_ERR("Cannot open flash area for slot %s", img_set);
+		return false;
+	}
+
+	ret = boot_read_swap_state(fa, &state);
+	if (ret != 0) {
+		LOG_ERR("Cannot read swap state for slot %s", img_set);
+	} else if (state.image_ok == BOOT_FLAG_SET) {
+		confirmed = true;
+	} else {
+		confirmed = false;
+	}
+
+	flash_area_close(fa);
+
+	return confirmed;
+}
+
+static void device_healthcheck(void)
+{
+	int err;
+	char *img_set = NULL;
+	enum boot_slot active_slot = active_boot_slot_get();
+
+	/* Confirming only in non-degraded boot states */
+	if (active_slot == BOOT_SLOT_PRIMARY) {
+		img_set = "A";
+	} else if (active_slot == BOOT_SLOT_SECONDARY) {
+		img_set = "B";
+	} else {
+		LOG_ERR("Cannot determine active slot for health check");
+		return;
+	}
+
+	if (slot_confirmed(active_slot)) {
+		LOG_INF("Slot %s already confirmed, no action needed", img_set);
+		return;
 	}
 
 	LOG_INF("Testing image set %s...", img_set);
@@ -149,40 +181,40 @@ static void device_healthcheck(void)
 
 	LOG_INF("Confirming...");
 
-	if (flash_area_open(area_id, &fa) != 0) {
-		LOG_ERR("Cannot open flash area for slot %s", img_set);
-		return;
-	}
-
-	err = boot_set_next(fa, true, true);
-
-	flash_area_close(fa);
+	err = boot_request_confirm_slot(ACTIVE_IMAGE, active_slot);
 	if (err == 0) {
 		LOG_INF("Confirmed\n");
 	} else {
 		LOG_ERR("Failed to confirm, err: %d", err);
 	}
 }
 
-static void select_slot_for_single_boot(enum ab_boot_slot slot)
+static void select_slot_for_single_boot(enum boot_slot slot)
 {
 	int err = 0;
-	char active_slot = (active_boot_slot_get() == SLOT_A) ? 'A' : 'B';
-	enum boot_slot new_slot = BOOT_SLOT_NONE;
+	char active_slot = (active_boot_slot_get() == BOOT_SLOT_PRIMARY) ? 'A' : 'B';
 
-	if (slot == SLOT_A) {
+#ifdef CONFIG_NRF_MCUBOOT_BOOT_REQUEST_PREFERENCE_KEEP
+	if (slot == BOOT_SLOT_PRIMARY) {
+		LOG_INF("Switching slots (%c -> A)", active_slot);
+	} else if (slot == BOOT_SLOT_SECONDARY) {
+		LOG_INF("Switching slots (%c -> B)", active_slot);
+	} else {
+		LOG_ERR("Cannot determine active slot, cannot toggle");
+		return;
+	}
+#else
+	if (slot == BOOT_SLOT_PRIMARY) {
 		LOG_INF("Temporarily switching slots (%c -> A)", active_slot);
-		new_slot = BOOT_SLOT_PRIMARY;
-	} else if (slot == SLOT_B) {
+	} else if (slot == BOOT_SLOT_SECONDARY) {
 		LOG_INF("Temporarily switching slots (%c -> B)", active_slot);
-		new_slot = BOOT_SLOT_SECONDARY;
 	} else {
 		LOG_ERR("Cannot determine active slot, cannot toggle");
 		return;
 	}
+#endif
 
-	err = boot_request_set_preferred_slot(ACTIVE_IMAGE, new_slot);
-
+	err = boot_request_set_preferred_slot(ACTIVE_IMAGE, slot);
 	if (err == 0) {
 		LOG_INF("Slot toggled, restart the device to enforce");
 	} else {
@@ -192,11 +224,11 @@ static void select_slot_for_single_boot(enum ab_boot_slot slot)
 
 static void boot_state_report(void)
 {
-	enum ab_boot_slot active_slot = active_boot_slot_get();
+	enum boot_slot active_slot = active_boot_slot_get();
 
-	if (active_slot == SLOT_A) {
+	if (active_slot == BOOT_SLOT_PRIMARY) {
 		LOG_INF("Booted from slot A");
-	} else if (active_slot == SLOT_B) {
+	} else if (active_slot == BOOT_SLOT_SECONDARY) {
 		LOG_INF("Booted from slot B");
 	} else {
 		LOG_INF("Cannot determine active slot");
@@ -206,9 +238,9 @@ static void boot_state_report(void)
 static void button_handler(uint32_t button_state, uint32_t has_changed)
 {
 	if ((has_changed & DK_BTN1_MSK) && (button_state & DK_BTN1_MSK)) {
-		select_slot_for_single_boot(SLOT_A);
+		select_slot_for_single_boot(BOOT_SLOT_PRIMARY);
 	} else if ((has_changed & DK_BTN2_MSK) && (button_state & DK_BTN2_MSK)) {
-		select_slot_for_single_boot(SLOT_B);
+		select_slot_for_single_boot(BOOT_SLOT_SECONDARY);
 	}
 }
 
@@ -217,11 +249,11 @@ struct k_thread status_leds_thread_data;
 static void status_leds_thread_entry_point(void *p1, void *p2, void *p3)
 {
 	int blinking_led = DK_LED1;
-	enum ab_boot_slot active_slot = active_boot_slot_get();
+	enum boot_slot active_slot = active_boot_slot_get();
 
-	if (active_slot == SLOT_A) {
+	if (active_slot == BOOT_SLOT_PRIMARY) {
 		blinking_led = DK_LED1;
-	} else if (active_slot == SLOT_B) {
+	} else if (active_slot == BOOT_SLOT_SECONDARY) {
 		blinking_led = DK_LED2;
 	} else {
 		return;

samples/dfu/ab/sysbuild.conf

@@ -1,10 +1,5 @@
 # Enable MCUboot bootloader support
 SB_CONFIG_BOOTLOADER_MCUBOOT=y
 
-# Enable radiocore
-SB_CONFIG_NETCORE_IPC_RADIO=y
-SB_CONFIG_NETCORE_IPC_RADIO_BT_HCI_IPC=y
-
 # Enable direct XIP with revert support
 SB_CONFIG_MCUBOOT_MODE_DIRECT_XIP_WITH_REVERT=y
-SB_CONFIG_MCUBOOT_IMAGES_ROM_END_OFFSET_AUTO="ipc_radio;ipc_radio_secondary_app"

samples/dfu/ab/sysbuild/mcuboot/boards/nrf54l15dk_nrf54l15_cpuapp.conf

@@ -7,3 +7,7 @@ CONFIG_PM_PARTITION_SIZE_MCUBOOT=0x10800
 # CONFIG_LOG=n
 # CONFIG_FPROTECT=y
 CONFIG_FPROTECT=n
+
+# Enable boot requests through retained memory.
+CONFIG_RETAINED_MEM=y
+CONFIG_RETENTION=y

samples/dfu/ab/sysbuild/mcuboot/prj.conf

@@ -1,12 +1,10 @@
-# Enable boot requests through retained memory.
-CONFIG_RETAINED_MEM=y
-CONFIG_RETENTION=y
+# Enable boot requests.
+CONFIG_CRC=y
 CONFIG_NRF_MCUBOOT_BOOT_REQUEST=y
 
 CONFIG_NRF_SECURITY=y
 CONFIG_MULTITHREADING=y
 
-
 # Configuration below is copied from mcuboot/boot/zephyr/prj.conf, as creating
 # the sysbuild/mcuboot directory inside a sample removes the default configuration.