sysbuild: Remove IMAGES variable

This variable was originally provided for two indended purposes:

  * Let users manually add a new image in a desired order in the list.
  * Let users set build-only images, which are excluded from the list.

Given the recent additions of the `sysbuild_add_dependencies()` function
and the `BUILD_ONLY` parameter, `IMAGES` should be considered obsolete.

Furthermore, the list of images added to sysbuild should be updated
automatically when calling `ExternalZephyrProject_Add()`. This is now
possible by using a GLOBAL property internal to sysbuild.

With that, the `IMAGES` variable can be removed. Its existing usage for
image ordering is replaced with `sysbuild_add_dependencies()` treewide.

Signed-off-by: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>

samples/drivers/ipm/ipm_mcux/sysbuild.cmake

@@ -9,9 +9,13 @@ ExternalZephyrProject_Add(
     BOARD ${SB_CONFIG_IPM_REMOTE_BOARD}
   )
 
-# Add a dependency so that the remote sample will be built and flashed first
+# Add dependencies so that the remote sample will be built first
 # This is required because some primary cores need information from the
 # remote core's build, such as the output image's LMA
 add_dependencies(ipm_mcux ipm_mcux_remote)
-# Place remote image first in the image list
-set(IMAGES "ipm_mcux_remote" ${IMAGES})
+sysbuild_add_dependencies(CONFIGURE ipm_mcux ipm_mcux_remote)
+
+if(SB_CONFIG_BOOTLOADER_MCUBOOT)
+  # Make sure MCUboot is flashed first
+  sysbuild_add_dependencies(FLASH ipm_mcux_remote mcuboot)
+endif()

samples/subsys/ipc/openamp/sysbuild.cmake

@@ -9,9 +9,13 @@ ExternalZephyrProject_Add(
     BOARD ${SB_CONFIG_OPENAMP_REMOTE_BOARD}
   )
 
-# Add a dependency so that the remote sample will be built and flashed first
+# Add dependencies so that the remote sample will be built first
 # This is required because some primary cores need information from the
 # remote core's build, such as the output image's LMA
 add_dependencies(openamp openamp_remote)
-# Place remote image first in the image list
-set(IMAGES "openamp_remote" ${IMAGES})
+sysbuild_add_dependencies(CONFIGURE openamp openamp_remote)
+
+if(SB_CONFIG_BOOTLOADER_MCUBOOT)
+  # Make sure MCUboot is flashed first
+  sysbuild_add_dependencies(FLASH openamp_remote mcuboot)
+endif()

share/sysbuild/CMakeLists.txt

@@ -24,9 +24,6 @@ find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE} COMPONENTS ${zephyr_modules
 
 project(sysbuild LANGUAGES)
 
-# Global list of images enabled in this multi image build system.
-set(IMAGES)
-
 get_filename_component(APP_DIR  ${APP_DIR} ABSOLUTE)
 get_filename_component(app_name ${APP_DIR} NAME)
 
@@ -54,7 +51,6 @@ ExternalZephyrProject_Add(
   SOURCE_DIR ${APP_DIR}
   APP_TYPE MAIN
 )
-list(APPEND IMAGES "${app_name}")
 set(DEFAULT_IMAGE "${app_name}")
 
 add_subdirectory(bootloader)
@@ -63,6 +59,7 @@ add_subdirectory(bootloader)
 include(${BOARD_DIR}/sysbuild.cmake OPTIONAL)
 
 # This allows image specific sysbuild.cmake to be processed.
+get_property(IMAGES GLOBAL PROPERTY sysbuild_images)
 list(LENGTH IMAGES images_length)
 while(NOT "${images_length}" EQUAL "${processed_length}")
   foreach(image ${IMAGES})
@@ -73,6 +70,7 @@ while(NOT "${images_length}" EQUAL "${processed_length}")
     endif()
   endforeach()
 
+  get_property(IMAGES GLOBAL PROPERTY sysbuild_images)
   list(LENGTH IMAGES images_length)
   list(LENGTH images_sysbuild_processed processed_length_new)
 

share/sysbuild/bootloader/CMakeLists.txt

@@ -12,7 +12,7 @@ if(SB_CONFIG_BOOTLOADER_MCUBOOT)
   )
   # MCUBoot default configuration is to perform a full chip erase.
   # Placing MCUBoot first in list to ensure it is flashed before other images.
-  set(IMAGES ${image} ${IMAGES} PARENT_SCOPE)
+  sysbuild_add_dependencies(FLASH ${DEFAULT_IMAGE} ${image})
 
   set_config_string(${image} CONFIG_BOOT_SIGNATURE_KEY_FILE "${SB_CONFIG_BOOT_SIGNATURE_KEY_FILE}")
 endif()

share/sysbuild/cmake/modules/sysbuild_extensions.cmake

@@ -155,6 +155,11 @@ function(ExternalZephyrProject_Add)
 
   endif()
 
+  set_property(
+    GLOBAL
+    APPEND PROPERTY sysbuild_images ${ZBUILD_APPLICATION}
+  )
+
   set(sysbuild_image_conf_dir ${APP_DIR}/sysbuild)
   set(sysbuild_image_name_conf_dir ${APP_DIR}/sysbuild/${ZBUILD_APPLICATION})
   # User defined `-D<image>_CONF_FILE=<file.conf>` takes precedence over anything else.

tests/boot/test_mcuboot/sysbuild.cmake

@@ -15,11 +15,12 @@ ExternalZephyrProject_Add(
 )
 
 # Add the swapped app to the list of images to flash
-# Ensure the order of images is as follows:
+# Ensure the flashing order of images is as follows:
 # - mcuboot
 # - swapped app
 # - primary app (test_mcuboot)
 # This order means that if the debugger resets the MCU in between flash
 # iterations, the MCUBoot swap won't be triggered until the secondary app
 # is actually present in flash.
-set(IMAGES "mcuboot" "swapped_app" "test_mcuboot")
+sysbuild_add_dependencies(FLASH test_mcuboot swapped_app)
+sysbuild_add_dependencies(FLASH swapped_app mcuboot)