sysbuild: image_flasher: Set board target correctly

This is not used by the image flasher CMake project but might be
queried by external systems

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

Author: nordicjm

sysbuild/image_flasher.cmake

@@ -25,15 +25,21 @@ function(add_image_flasher)
   set(${args_NAME}_HEX_FILE "${args_HEX_FILE}" CACHE FILEPATH "Hex file to flash" FORCE)
   set(IMAGE_FLASHER_DEFAULT_IMAGE ${DEFAULT_IMAGE} CACHE STRING "Default image" FORCE)
 
+  if(args_BASE_IMAGE)
+    set(${args_NAME}_IMAGE_FLASHER_SPECIFIC_IMAGE ${args_BASE_IMAGE} CACHE STRING "Base image" FORCE)
+    get_target_property(image_flasher_target_board ${args_BASE_IMAGE} BOARD)
+
+    if(image_flasher_target_board)
+      set(image_flasher_target_board BOARD ${image_flasher_target_board})
+    endif()
+  endif()
+
   ExternalZephyrProject_Add(
     APPLICATION ${args_NAME}
     SOURCE_DIR ${ZEPHYR_NRF_MODULE_DIR}/applications/image_flasher
+    ${image_flasher_target_board}
   )
 
-  if(args_BASE_IMAGE)
-    set(${args_NAME}_IMAGE_FLASHER_SPECIFIC_IMAGE ${args_BASE_IMAGE} CACHE STRING "Base image" FORCE)
-  endif()
-
   # Must be configured after the default image as the default image Kconfig and dts files are
   # copied.
   sysbuild_add_dependencies(CONFIGURE ${args_NAME} ${DEFAULT_IMAGE})