cmake: multi image build support

Add support for non-recursive single-toolchain multi-image
builds. This resolves #7868.

We are seeing the need to boot Zephyr applications in multiple
stages, a real-world usecase of even a 3-stage bootloader has
been identified and tested.

Each bootloader needs to be individually upgrade-able and have
it's own configurations of Zephyr libraries. To achieve this each
bootloader is organized as it's own executable.

The problem is that the build system can only build one
executable. This creates a usability issue as the user must invoke a
large set of arcane commands to build, sign, and flash each
bootloader.

To resolve this we re-organize the build system such that it can build
multiple executables.

Signed-off-by: Sebastian Bøe <[email protected]>
Signed-off-by: Håkon Øye Amundsen <[email protected]>

Author: SebastianBoe

CMakeLists.txt

@@ -17,7 +17,7 @@ zephyr_compile_options(
 # @Intent: Obtain compiler specific flags for no freestanding compilation
 toolchain_cc_no_freestanding_options()
 
-zephyr_include_directories(${BOARD_DIR})
+zephyr_include_directories(${${IMAGE}BOARD_DIR})
 
 if (CONFIG_COVERAGE)
   toolchain_cc_coverage()

arch/posix/CMakeLists.txt

@@ -1,9 +1,7 @@
 # Copyright (c) 2019 Intel Corp.
 # SPDX-License-Identifier: Apache-2.0
 
-# Find out if we are optimizing for size
-get_target_property(zephyr_COMPILE_OPTIONS zephyr_interface INTERFACE_COMPILE_OPTIONS)
-if ("-Os" IN_LIST zephyr_COMPILE_OPTIONS)
+if(CONFIG_SIZE_OPTIMIZATIONS)
   zephyr_cc_option(-mpreferred-stack-boundary=2)
 else()
   zephyr_compile_definitions(PERF_OPT)
@@ -40,8 +38,9 @@ set(gen_idt_output_files
   ${CMAKE_CURRENT_BINARY_DIR}/staticIdt.bin
   ${CMAKE_CURRENT_BINARY_DIR}/irq_vectors_alloc.bin
   )
+set(gen_idt_output_target ${IMAGE}gen_idt_output)
 add_custom_target(
-  gen_idt_output
+  ${gen_idt_output_target}
   DEPENDS
   ${gen_idt_output_files}
   )
@@ -82,25 +81,26 @@ function(add_bin_file_to_the_next_link target_dependency bin)
     DEPENDS ${target_dependency} ${bin}.bin
     WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
     )
-  add_custom_target(${bin}_o DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${bin}.o)
-  add_library(${bin} STATIC IMPORTED GLOBAL)
-  set_property(TARGET ${bin} PROPERTY IMPORTED_LOCATION ${CMAKE_CURRENT_BINARY_DIR}/${bin}.o)
-  add_dependencies(${bin} ${bin}_o)
-  set_property(TARGET ${ZEPHYR_TARGET} APPEND PROPERTY GENERATED_KERNEL_OBJECT_FILES ${bin})
+  add_custom_target(${IMAGE}${bin}_o DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${bin}.o)
+  add_library(${IMAGE}${bin} STATIC IMPORTED GLOBAL)
+  set_property(TARGET ${IMAGE}${bin} PROPERTY IMPORTED_LOCATION ${CMAKE_CURRENT_BINARY_DIR}/${bin}.o)
+  add_dependencies(${IMAGE}${bin} ${IMAGE}${bin}_o)
+  set_property(TARGET ${ZEPHYR_TARGET} APPEND PROPERTY GENERATED_KERNEL_OBJECT_FILES ${IMAGE}${bin})
 endfunction()
 
-add_bin_file_to_the_next_link(gen_idt_output staticIdt)
-add_bin_file_to_the_next_link(gen_idt_output irq_int_vector_map)
-add_bin_file_to_the_next_link(gen_idt_output irq_vectors_alloc)
+add_bin_file_to_the_next_link(${gen_idt_output_target} staticIdt)
+add_bin_file_to_the_next_link(${gen_idt_output_target} irq_int_vector_map)
+add_bin_file_to_the_next_link(${gen_idt_output_target} irq_vectors_alloc)
 
 if(CONFIG_GDT_DYNAMIC)
   # Use gen_gdt.py and objcopy to generate gdt.o from from the elf
   # file ${ZEPHYR_PREBUILT_EXECUTABLE}, creating the temp file gdt.bin along the
   # way.
   #
   # ${ZEPHYR_PREBUILT_EXECUTABLE}.elf -> gdt.bin -> gdt.o
+  set(gdt_bin_target ${IMAGE}gdt_bin)
   add_custom_target(
-    gdt_bin_target
+    ${gdt_bin_target}
     DEPENDS
     gdt.bin
   )
@@ -116,5 +116,5 @@ if(CONFIG_GDT_DYNAMIC)
     WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
     )
 
-  add_bin_file_to_the_next_link(gdt_bin_target gdt)
+  add_bin_file_to_the_next_link(${gdt_bin_target} gdt)
 endif()

arch/x86/ia32.cmake

@@ -3,12 +3,12 @@
 # To avoid a lot of empty CMakeLists.txt files we assume it is not an
 # error if it is missing
 
-if(EXISTS ${BOARD_DIR}/CMakeLists.txt)
+if(EXISTS ${${IMAGE}BOARD_DIR}/CMakeLists.txt)
   if(USING_OUT_OF_TREE_BOARD)
-	set(build_dir boards/${ARCH}/${BOARD})
+	set(build_dir boards/${ARCH}/${${IMAGE}BOARD})
   else()
 	unset(build_dir)
   endif()
 
-  add_subdirectory(${BOARD_DIR} ${build_dir})
+  add_subdirectory(${${IMAGE}BOARD_DIR} ${build_dir})
 endif()

boards/CMakeLists.txt

@@ -4,6 +4,8 @@
 # SPDX-License-Identifier: Apache-2.0
 #
 
+message(STATUS "============================ HELLO FOR ${BOARD}")
+
 set_ifndef(LPCLINK_FW jlink)
 
 if(LPCLINK_FW STREQUAL jlink)

boards/arm/lpcxpresso54114/board.cmake

@@ -14,7 +14,7 @@ set_property(TARGET   ${ZEPHYR_TARGET} PROPERTY   QEMU_FLAGS_${ARCH}
   )
 
 set(QEMU_KERNEL_OPTION
-  "-device;loader,file=$<TARGET_FILE:zephyr_final>,cpu-num=4"
+  "-device;loader,file=$<TARGET_FILE:${IMAGE}zephyr_final>,cpu-num=4"
   )
 
 board_set_debugger_ifnset(qemu)

boards/arm/qemu_cortex_r5/board.cmake

@@ -6,7 +6,7 @@ if(CONFIG_PINMUX_INTEL_S1000)
 endif()
 
 set_property(TARGET ${ZEPHYR_TARGET} APPEND PROPERTY extra_post_build_commands
-  COMMAND ${PYTHON_EXECUTABLE} ${BOARD_DIR}/support/create_board_img.py
+  COMMAND ${PYTHON_EXECUTABLE} ${${IMAGE}BOARD_DIR}/support/create_board_img.py
   -i ${PROJECT_BINARY_DIR}/${CONFIG_KERNEL_BIN_NAME}.bin
   -o ${PROJECT_BINARY_DIR}/${CONFIG_KERNEL_BIN_NAME}_${BOARD}.bin
   -l $<TARGET_FILE:${ZEPHYR_PREBUILT_EXECUTABLE}>

boards/xtensa/intel_s1000_crb/CMakeLists.txt

@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2019 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+choice
+	prompt "build strategy"
+	default $(image)_BUILD_STRATEGY_FROM_SOURCE
+
+config $(image)_BUILD_STRATEGY_SKIP_BUILD
+	# Mandatory option when being built through 'zephyr_add_image'
+	bool "Skip building"
+
+config $(image)_BUILD_STRATEGY_FROM_SOURCE
+	# Mandatory option when being built through 'zephyr_add_image'
+	bool "Build from source"
+
+endchoice