samples: dfu: ab sample nrf54L15 support

This commit adds support for nRF54L15 in the
DFU A/B sample

Signed-off-by: Artur Hadasz <[email protected]>

Author: ahasztag

samples/dfu/ab/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#include "../sysbuild/nrf54l15dk_nrf54l15_cpuapp_common.dtsi"

samples/dfu/ab/sample.yaml

@@ -13,5 +13,7 @@ tests:
     sysbuild: true
     platform_allow:
       - nrf54h20dk/nrf54h20/cpuapp
+      - nrf54l15dk/nrf54l15/cpuapp
     integration_platforms:
       - nrf54h20dk/nrf54h20/cpuapp
+      - nrf54l15dk/nrf54l15/cpuapp

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

@@ -0,0 +1,9 @@
+CONFIG_PM_PARTITION_SIZE_MCUBOOT=0x10800
+
+# The default MCUboot is too large to support fprotect.
+# To use fprotect disable logs or perform other size optimizations.
+# For example, do:
+# CONFIG_PM_PARTITION_SIZE_MCUBOOT=0xE800
+# CONFIG_LOG=n
+# CONFIG_FPROTECT=y
+CONFIG_FPROTECT=n

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

@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#include "../../nrf54l15dk_nrf54l15_cpuapp_common.dtsi"

samples/dfu/ab/sysbuild/nrf54l15dk_nrf54l15_cpuapp_common.dtsi

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/ {
+	chosen {
+		nrf,bootloader-request = &boot_request;
+	};
+};
+
+/ {
+	cpuapp_sram@2003FFF0 {
+		compatible = "zephyr,memory-region", "mmio-sram";
+		reg = <0x2003FFF0 0x10>;
+		zephyr,memory-region = "RetainedMem";
+		status = "okay";
+		retainedmem {
+			compatible = "zephyr,retained-ram";
+			status = "okay";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			boot_request: boot_request@0 {
+				compatible = "zephyr,retention";
+				status = "okay";
+				reg = <0x0 0x10>;
+				prefix = [0B 01];
+				checksum = <4>;
+			};
+		};
+	};
+};