cmake(feat):implements KERNEL mode in CMake build

1.add application link dependencies for all elf
2.add a global custom target to hold proptry in the toolchain file
3.add startup obj target
4.fix cpp lds error with kernel mod link elf lds

usage:
./build.sh qemu-armv7a:knsh --cmake
elf install in ${CMAKE_BINARY_DIR}/bin

Signed-off-by: xuxin19 <xuxin19@xiaomi.com>

CMakeLists.txt

@@ -378,6 +378,12 @@ if(NOT EXISTS ${CMAKE_BINARY_DIR}/.config OR NOT "${NUTTX_DEFCONFIG}" STREQUAL
   message(STATUS "  Appdir: ${NUTTX_APPS_DIR}")
 endif()
 
+# declare global custom targets at very beginning `nuttx_global` is used to hold
+# global target properties to solve that cmake GLOBAL property can not use
+# generator expression this is needed to make sure added before project() create
+# before Toolchain file added before all cmake modules are loaded
+add_custom_target(nuttx_global)
+
 # Include .cmake files #######################################################
 
 # this exposes all Kconfig vars to CMake
@@ -598,15 +604,11 @@ endif()
 
 # Add apps/ to the build (if present)
 
-if(NOT CONFIG_BUILD_KERNEL)
-
-  if(EXISTS ${NUTTX_APPS_DIR}/CMakeLists.txt)
-    add_subdirectory(${NUTTX_APPS_DIR} apps)
-  else()
-    message(
-      STATUS "Application directory not found at ${NUTTX_APPS_DIR}, skipping")
-  endif()
-
+if(EXISTS ${NUTTX_APPS_DIR}/CMakeLists.txt)
+  add_subdirectory(${NUTTX_APPS_DIR} apps)
+else()
+  message(
+    STATUS "Application directory not found at ${NUTTX_APPS_DIR}, skipping")
 endif()
 
 # after we traverse all build directories unify all target dependencies and all

arch/arm/src/common/CMakeLists.txt

@@ -92,3 +92,5 @@ if(CONFIG_ARCH_HAVE_FETCHADD)
 endif()
 
 target_sources(arch PRIVATE ${SRCS})
+
+nuttx_add_aux_library(STARTUP_OBJS crt0.c)

arch/arm/src/qemu/CMakeLists.txt

@@ -23,7 +23,7 @@
 set(SRCS qemu_boot.c qemu_serial.c qemu_irq.c qemu_timer.c)
 
 if(CONFIG_ARCH_ARMV7A)
-  list(APPEND SRCS qemu_memorymap.c)
+  list(APPEND SRCS qemu_pgalloc.c qemu_memorymap.c)
 endif()
 
 if(CONFIG_SMP)

cmake/nuttx_add_application.cmake

@@ -112,14 +112,18 @@ function(nuttx_add_application)
       # non-elf output
       if(NOT CMAKE_C_ELF_COMPILER)
         add_library(${TARGET} ${SRCS})
-
+        add_dependencies(${TARGET} nuttx_post)
         add_custom_command(
           TARGET ${TARGET}
           POST_BUILD
           COMMAND
-            ${CMAKE_C_COMPILER}
-            $<GENEX_EVAL:$<TARGET_PROPERTY:nuttx,NUTTX_ELF_APP_LINK_OPTIONS>>
-            $<TARGET_FILE:${TARGET}> -o ${TARGET}
+            ${CMAKE_LD}
+            $<GENEX_EVAL:$<TARGET_PROPERTY:nuttx_global,NUTTX_ELF_APP_LINK_OPTIONS>>
+            -e __start -Bstatic -T ${CMAKE_BINARY_DIR}/gnu-elf.ld
+            $<TARGET_OBJECTS:STARTUP_OBJS> --start-group
+            $<GENEX_EVAL:$<TARGET_PROPERTY:nuttx_global,NUTTX_ELF_LINK_LIBRARIES>>
+            $<TARGET_FILE:${TARGET}> --end-group -o
+            ${CMAKE_BINARY_DIR}/bin/${TARGET}
           COMMAND_EXPAND_LISTS)
       else()
         add_executable(${TARGET} ${SRCS})

cmake/nuttx_add_library.cmake

@@ -118,6 +118,13 @@ function(nuttx_add_system_library target)
 
   # add to list of libraries to link to final nuttx binary
   set_property(GLOBAL APPEND PROPERTY NUTTX_SYSTEM_LIBRARIES ${target})
+
+  set_property(
+    TARGET nuttx_global
+    APPEND
+    PROPERTY NUTTX_ELF_LINK_LIBRARIES $<TARGET_FILE:${target}>)
+
+  add_dependencies(nuttx_post ${target})
 endfunction()
 
 # Kernel Libraries
@@ -196,6 +203,14 @@ function(nuttx_add_library target)
   add_library(${target} ${ARGN})
   add_dependencies(${target} apps_context)
   set_property(GLOBAL APPEND PROPERTY NUTTX_SYSTEM_LIBRARIES ${target})
+
+  set_property(
+    TARGET nuttx_global
+    APPEND
+    PROPERTY NUTTX_ELF_LINK_LIBRARIES $<TARGET_FILE:${target}>)
+
+  add_dependencies(nuttx_post ${target})
+
   # Set apps global compile options & definitions hold by nuttx_apps_interface
   target_compile_options(
     ${target}
@@ -236,6 +251,12 @@ function(nuttx_add_extra_library)
         set_property(GLOBAL APPEND PROPERTY NUTTX_USER_EXTRA_LIBRARIES
                                             ${extra_target})
       endif()
+      if(CONFIG_BUILD_KERNEL)
+        set_property(
+          TARGET nuttx_global
+          APPEND
+          PROPERTY NUTTX_ELF_LINK_LIBRARIES $<TARGET_FILE:${extra_target}>)
+      endif()
     endif()
   endforeach()
 endfunction()
@@ -259,6 +280,11 @@ function(nuttx_add_external_library target)
   cmake_parse_arguments(ARGS "" MODE "" ${ARGN})
   if(NOT ARGS_MODE)
     set_property(GLOBAL APPEND PROPERTY NUTTX_SYSTEM_LIBRARIES ${target})
+    set_property(
+      TARGET nuttx_global
+      APPEND
+      PROPERTY NUTTX_ELF_LINK_LIBRARIES $<TARGET_FILE:${target}>)
+    add_dependencies(nuttx_post ${target})
   elseif("${ARGS_MODE}" STREQUAL "APPS")
     set_property(GLOBAL APPEND PROPERTY NUTTX_APPS_LIBRARIES ${target})
   elseif("${ARGS_MODE}" STREQUAL "KERNEL")

cmake/nuttx_extensions.cmake

@@ -281,6 +281,14 @@ function(nuttx_compile_definitions_for_all_apps)
     PROPERTY APPS_COMPILE_DEFINITIONS ${ARGN})
 endfunction()
 
+# all elf link options
+function(nuttx_add_elf_link_options)
+  set_property(
+    TARGET nuttx_global
+    APPEND
+    PROPERTY NUTTX_ELF_APP_LINK_OPTIONS ${ARGN})
+endfunction()
+
 # since we dont call `target_link_libraries` directly, we only inherit their
 # compilation configuration
 function(nuttx_link_libraries)

cmake/nuttx_toolchain.cmake

@@ -91,7 +91,7 @@ if(NOT NUTTX_TOOLCHAIN_PREPROCESS_DEFINED)
 
     add_custom_command(
       OUTPUT ${TARGET_FILE}
-      COMMAND ${PREPROCESS} -I${CMAKE_BINARY_DIR}/include
+      COMMAND ${PREPROCESS} -I${CMAKE_BINARY_DIR}/include -I${NUTTX_DIR}/include
               -I${NUTTX_CHIP_ABS_DIR} ${SOURCE_FILE} > ${TARGET_FILE}
       DEPENDS ${SOURCE_FILE} ${DEPENDS})
 

libs/libc/elf/CMakeLists.txt

@@ -49,4 +49,13 @@ if(CONFIG_LIBC_ELF)
 
   target_sources(c PRIVATE ${SRCS})
 
+  set(ELF_LD_SCRIPT_TMP "${CMAKE_BINARY_DIR}/gnu-elf.ld")
+
+  nuttx_generate_preprocess_target(
+    SOURCE_FILE ${NUTTX_DIR}/libs/libc/elf/gnu-elf.ld.in TARGET_FILE
+    ${ELF_LD_SCRIPT_TMP})
+
+  add_custom_target(elfldscript_tmp DEPENDS ${ELF_LD_SCRIPT_TMP})
+  add_dependencies(nuttx elfldscript_tmp)
+
 endif()