sysbuild: Add firmware loader smp_svr_mini_boot image support

Adds support for picking this image as a firmware loader image

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

sysbuild/Kconfig.sysbuild

@@ -87,3 +87,5 @@ rsource "Kconfig.lwm2m_carrier"
 rsource "Kconfig.cracen"
 rsource "Kconfig.tfm"
 rsource "Kconfig.periphconf"
+
+rsource "images/firmware_loader/Kconfig"

sysbuild/images/firmware_loader/Kconfig

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config SUPPORT_FIRMWARE_LOADER_SMP_SVR_MINI_BOOT
+	bool
+	default y
+
+choice FIRMWARE_LOADER
+
+config FIRMWARE_LOADER_IMAGE_SMP_SVR_MINI_BOOT
+	bool "smp_svr_mini_boot"
+	depends on SUPPORT_FIRMWARE_LOADER_SMP_SVR_MINI_BOOT
+	help
+	  Include the minified MCUmgr ``smp_svr_mini_boot`` sample as the firmware loader image
+	  to use.
+
+endchoice
+
+config FIRMWARE_LOADER_IMAGE_NAME
+	default "smp_svr_mini_boot" if FIRMWARE_LOADER_IMAGE_SMP_SVR_MINI_BOOT
+
+config FIRMWARE_LOADER_IMAGE_PATH
+	default "${ZEPHYR_NRF_MODULE_DIR}/samples/zephyr/smp_svr_mini_boot" if FIRMWARE_LOADER_IMAGE_SMP_SVR_MINI_BOOT