cmake: Split out board listing from usage

In order to make board listing reusable by external tools, split it out
from the usage helper script into a new boards.cmake that can also be
called directly with cmake -P.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

cmake/boards.cmake

@@ -0,0 +1,118 @@
+# SPDX-License-Identifier: Apache-2.0
+
+# List all architectures, export the list in list_var
+function(list_archs list_var)
+
+  FILE(GLOB arch_contents RELATIVE $ENV{ZEPHYR_BASE}/arch $ENV{ZEPHYR_BASE}/arch/*)
+  set(_arch_list)
+  foreach(f ${arch_contents})
+    if ("${f}" STREQUAL "common")
+      continue()
+    endif()
+    if (IS_DIRECTORY "$ENV{ZEPHYR_BASE}/arch/${f}")
+      list(APPEND _arch_list "${f}")
+    endif()
+  endforeach()
+
+  # Export the arch list to the parent scope
+  set(${list_var} ${_arch_list} PARENT_SCOPE)
+endfunction()
+
+# List all boards for a particular arch, export the list in list_var
+function(list_boards arch list_var)
+
+  # Make sure we start with an empty list for each arch
+  set(_boards_for_${arch} "")
+  foreach(root ${BOARD_ROOT})
+    set(board_arch_dir ${root}/boards/${arch})
+
+    # Match the _defconfig files in the board directories to make sure we are
+    # finding boards, e.g. qemu_xtensa/qemu_xtensa_defconfig
+    file(GLOB_RECURSE defconfigs_for_${arch}
+      RELATIVE ${board_arch_dir}
+      ${board_arch_dir}/*_defconfig
+      )
+
+    # The above gives a list like
+    # nrf51_blenano/nrf51_blenano_defconfig;nrf51_pca10028/nrf51_pca10028_defconfig
+    # we construct a list of board names by removing both the _defconfig
+    # suffix and the path.
+    foreach(defconfig_path ${defconfigs_for_${arch}})
+      get_filename_component(board ${defconfig_path} NAME)
+      string(REPLACE "_defconfig" "" board "${board}")
+      list(APPEND _boards_for_${arch} ${board})
+    endforeach()
+
+  endforeach()
+
+  # Export the board list for this arch to the parent scope
+  set(${list_var} ${_boards_for_${arch}} PARENT_SCOPE)
+endfunction()
+
+# Function to dump and optionally save to a file all architectures and boards
+# Takes the board root as a semicolon-separated list in:
+# BOARD_ROOT
+# Additional arguments:
+# file_out Filename to save the boards list. If not defined, stdout will be used
+# indent Prepend an additional indendation string to each line
+function(dump_all_boards file_out indent)
+
+  set(arch_list)
+  list_archs(arch_list)
+
+  foreach(arch ${arch_list})
+    list_boards(${arch} boards_for_${arch})
+  endforeach()
+
+  if(file_out)
+    file(WRITE ${file_out} "")
+  endif()
+
+  foreach(arch ${arch_list})
+    set(_arch_str "${indent}${arch}:")
+    if(file_out)
+      file(APPEND ${file_out} "${_arch_str}\n")
+    else()
+      message(${_arch_str})
+    endif()
+    foreach(board ${boards_for_${arch}})
+      set(_board_str "${indent}  ${board}")
+      if(file_out)
+         file(APPEND ${file_out} "${_board_str}\n")
+      else()
+         message(${_board_str})
+      endif()
+    endforeach()
+  endforeach()
+
+endfunction()
+
+if(CMAKE_SCRIPT_MODE_FILE AND NOT CMAKE_PARENT_LIST_FILE)
+# If this file is invoked as a script directly with -P:
+# cmake [options] -P board.cmake
+# Note that CMAKE_PARENT_LIST_FILE not being set ensures that this present
+# file is being invoked directly with -P, and not via an include directive from
+# some other script
+
+# The options available are:
+# BOARD_ROOT_SPACE_SEPARATED: Space-separated board roots
+# FILE_OUT: Set to a file path to save the boards to a file. If not defined the
+#           the contents will be printed to stdout
+if(NOT DEFINED ENV{ZEPHYR_BASE})
+  message(FATAL_ERROR "ZEPHYR_BASE not set")
+endif()
+
+if (NOT BOARD_ROOT_SPACE_SEPARATED)
+  message(FATAL_ERROR "BOARD_ROOT_SPACE_SEPARATED not defined")
+endif()
+
+string(REPLACE " " ";" BOARD_ROOT "${BOARD_ROOT_SPACE_SEPARATED}")
+
+if (NOT FILE_OUT)
+  set(FILE_OUT FALSE)
+endif()
+
+dump_all_boards(${FILE_OUT} "")
+
+endif()
+

cmake/usage/usage.cmake

@@ -1,47 +1,17 @@
 # SPDX-License-Identifier: Apache-2.0
+if(NOT DEFINED ENV{ZEPHYR_BASE})
+  message(FATAL_ERROR "ZEPHYR_BASE not set")
+endif()
+
+include ($ENV{ZEPHYR_BASE}/cmake/boards.cmake)
 
 # TODO: Set to make when make is used as a generator
 set(CMAKE_MAKE_PROGRAM ninja)
 get_filename_component(generator ${CMAKE_MAKE_PROGRAM} NAME)
 
-set(arch_list
-  arc
-  arm
-  nios2
-  riscv32
-  posix
-  x86
-  x86_64
-  xtensa
-  )
-
 string(REPLACE " " ";" BOARD_ROOT "${BOARD_ROOT_SPACE_SEPARATED}")
 string(REPLACE " " ";" SHIELD_LIST "${SHIELD_LIST_SPACE_SEPARATED}")
 
-foreach(arch ${arch_list})
-  foreach(root ${BOARD_ROOT})
-    set(board_arch_dir ${root}/boards/${arch})
-
-    # Match the _defconfig files in the board directories to make sure we are
-    # finding boards, e.g. qemu_xtensa/qemu_xtensa_defconfig
-    file(GLOB_RECURSE defconfigs_for_${arch}
-      RELATIVE ${board_arch_dir}
-      ${board_arch_dir}/*_defconfig
-      )
-
-    # The above gives a list like
-    # nrf51_blenano/nrf51_blenano_defconfig;nrf51_pca10028/nrf51_pca10028_defconfig
-    # we construct a list of board names by removing both the _defconfig
-    # suffix and the path.
-    set(boards_for_${arch} "")
-    foreach(defconfig_path ${defconfigs_for_${arch}})
-      get_filename_component(board ${defconfig_path} NAME)
-      string(REPLACE "_defconfig" "" board "${board}")
-      list(APPEND boards_for_${arch} ${board})
-    endforeach()
-  endforeach()
-endforeach()
-
 message("Cleaning targets:")
 message("  clean     - Remove most generated files but keep configuration and backup files")
 message("  pristine  - Remove all files in the build directory")
@@ -72,12 +42,7 @@ message("  $ export BOARD=<BOARD NAME>")
 message("  $ export SHIELD=<SHIELD NAME> #optional")
 message("  $ cmake -Bpath/to/build_dir -Hpath/to/source_dir")
 message("")
-foreach(arch ${arch_list})
+dump_all_boards("" "  ")
-  message(" ${arch}:")
-  foreach(board ${boards_for_${arch}})
-    message("   ${board}")
-  endforeach()
-endforeach()
 message("")
 message("Supported Shields:")
 message("")