cmake: sysbuild: import image kconfig settings to image target

Load image kconfig setting into image target properties.
This allows sysbuild to evaluate and check image configuration as part
of CMake invocation.

sysbuild_get() is updated to support reading of CMake cache or Kconfig
settings for an image.

Signed-off-by: Torsten Rasmussen <[email protected]>

Author: tejlmand

cmake/modules/extensions.cmake

@@ -1425,13 +1425,21 @@ endfunction()
 
 # 2.1 Misc
 #
-# import_kconfig(<prefix> <kconfig_fragment> [<keys>])
+# import_kconfig(<prefix> <kconfig_fragment> [<keys>] [TARGET <target>])
 #
 # Parse a KConfig fragment (typically with extension .config) and
 # introduce all the symbols that are prefixed with 'prefix' into the
 # CMake namespace. List all created variable names in the 'keys'
 # output variable if present.
+#
+# <prefix>          : symbol prefix of settings in the Kconfig fragment.
+# <kconfig_fragment>: absolute path to the config fragment file.
+# <keys>            : output variable which will be populated with variable
+#                     names loaded from the kconfig fragment.
+# TARGET <target>   : set all symbols on <target> instead of adding them to the
+#                     CMake namespace.
 function(import_kconfig prefix kconfig_fragment)
+  cmake_parse_arguments(IMPORT_KCONFIG "" "TARGET" "" ${ARGN})
   # Parse the lines prefixed with 'prefix' in ${kconfig_fragment}
   file(
     STRINGS
@@ -1457,16 +1465,23 @@ function(import_kconfig prefix kconfig_fragment)
       set(CONF_VARIABLE_VALUE ${CMAKE_MATCH_1})
     endif()
 
-    set("${CONF_VARIABLE_NAME}" "${CONF_VARIABLE_VALUE}" PARENT_SCOPE)
+    if(DEFINED IMPORT_KCONFIG_TARGET)
+      set_property(TARGET ${IMPORT_KCONFIG_TARGET} APPEND PROPERTY "kconfigs" "${CONF_VARIABLE_NAME}")
+      set_property(TARGET ${IMPORT_KCONFIG_TARGET} PROPERTY "${CONF_VARIABLE_NAME}" "${CONF_VARIABLE_VALUE}")
+    else()
+      set("${CONF_VARIABLE_NAME}" "${CONF_VARIABLE_VALUE}" PARENT_SCOPE)
+    endif()
     list(APPEND keys "${CONF_VARIABLE_NAME}")
   endforeach()
 
-  if(ARGC GREATER 2)
-    if(ARGC GREATER 3)
+  list(LENGTH IMPORT_KCONFIG_UNPARSED_ARGUMENTS unparsed_length)
+  if(unparsed_length GREATER 0)
+    if(unparsed_length GREATER 1)
     # Two mandatory arguments and one optional, anything after that is an error.
-      message(FATAL_ERROR "Unexpected argument after '<keys>': import_kconfig(... ${ARGV3})")
+      list(GET IMPORT_KCONFIG_UNPARSED_ARGUMENTS 1 first_invalid)
+      message(FATAL_ERROR "Unexpected argument after '<keys>': import_kconfig(... ${first_invalid})")
     endif()
-    set(${ARGV2} "${keys}" PARENT_SCOPE)
+    set(${IMPORT_KCONFIG_UNPARSED_ARGUMENTS} "${keys}" PARENT_SCOPE)
   endif()
 endfunction()
 

share/sysbuild/cmake/modules/sysbuild_extensions.cmake

@@ -39,7 +39,7 @@ function(load_cache)
 endfunction()
 
 # Usage:
-#   sysbuild_get(<variable> IMAGE <image> [VAR <image-variable>])
+#   sysbuild_get(<variable> IMAGE <image> [VAR <image-variable>] <KCONFIG|CACHE>)
 #
 # This function will return the variable found in the CMakeCache.txt file
 # identified by image.
@@ -50,20 +50,26 @@ endfunction()
 # The result will be returned in `<variable>`.
 #
 # Example use:
-#   sysbuild_get(PROJECT_NAME IMAGE my_sample)
+#   sysbuild_get(PROJECT_NAME IMAGE my_sample CACHE)
 #     will lookup PROJECT_NAME from the CMakeCache identified by `my_sample` and
 #     and return the value in the local variable `PROJECT_NAME`.
 #
-#   sysbuild_get(my_sample_PROJECT_NAME IMAGE my_sample VAR PROJECT_NAME)
+#   sysbuild_get(my_sample_PROJECT_NAME IMAGE my_sample VAR PROJECT_NAME CACHE)
 #     will lookup PROJECT_NAME from the CMakeCache identified by `my_sample` and
 #     and return the value in the local variable `my_sample_PROJECT_NAME`.
 #
+#   sysbuild_get(my_sample_CONFIG_FOO IMAGE my_sample VAR CONFIG_FOO KCONFIG)
+#     will lookup CONFIG_FOO from the KConfig identified by `my_sample` and
+#     and return the value in the local variable `my_sample_CONFIG_FOO`.
+#
 # <variable>: variable used for returning CMake cache value. Also used as lookup
 #             variable if `VAR` is not provided.
 # IMAGE:      image name identifying the cache to use for variable lookup.
 # VAR:        name of the CMake cache variable name to lookup.
+# KCONFIG:    Flag indicating that a Kconfig setting should be fetched.
+# CACHE:      Flag indicating that a CMake cache variable should be fetched.
 function(sysbuild_get variable)
-  cmake_parse_arguments(GET_VAR "" "IMAGE;VAR" "" ${ARGN})
+  cmake_parse_arguments(GET_VAR "CACHE;KCONFIG" "IMAGE;VAR" "" ${ARGN})
 
   if(NOT DEFINED GET_VAR_IMAGE)
     message(FATAL_ERROR "sysbuild_get(...) requires IMAGE.")
@@ -81,7 +87,16 @@ function(sysbuild_get variable)
     set(GET_VAR_VAR ${variable})
   endif()
 
-  get_property(${GET_VAR_IMAGE}_${GET_VAR_VAR} TARGET ${GET_VAR_IMAGE}_cache PROPERTY ${GET_VAR_VAR})
+  if(GET_VAR_KCONFIG)
+    set(variable_target ${GET_VAR_IMAGE})
+  elseif(GET_VAR_CACHE)
+    set(variable_target ${GET_VAR_IMAGE}_cache)
+  else()
+    message(WARNING "<CACHE> or <KCONFIG> not specified, defaulting to CACHE")
+    set(variable_target ${GET_VAR_IMAGE}_cache)
+  endif()
+
+  get_property(${GET_VAR_IMAGE}_${GET_VAR_VAR} TARGET ${variable_target} PROPERTY ${GET_VAR_VAR})
   if(DEFINED ${GET_VAR_IMAGE}_${GET_VAR_VAR})
     set(${variable} ${${GET_VAR_IMAGE}_${GET_VAR_VAR}} PARENT_SCOPE)
   endif()
@@ -260,4 +275,5 @@ function(ExternalZephyrProject_Add)
     BUILD_ALWAYS True
     USES_TERMINAL_BUILD True
   )
+  import_kconfig(CONFIG_ ${CMAKE_BINARY_DIR}/${ZBUILD_APPLICATION}/zephyr/.config TARGET ${ZBUILD_APPLICATION})
 endfunction()