cmake: Added rule and helper functions for code relocation.

This patch creates a rule in the cmake to trigger the generation
of linker_relocate.ld and code_relocation.c files.
The linker_relocate.ld will create appropriate sections and will
link the required functions or variables from all the selected
files.
The code_relocation.c will have code that is needed for
initializing data sections and copy of text sections(if XIP).
Also this will contain code that is needed for zeroing of bss.

The procedure to invoke this feature is:
1. Enable CONFIG_CODE_RELOCATION in the prj.conf

2. Inside CMakeList.txt in the project we need to mention
   all the files that needs to get relocated.

   zephyr_kernel_code_relocate(src/*.c SRAM2)

   Where the first argument is the file/files and the second
   argument is the memory where it has be placed.
   NOTE: The file argument supports glob expressions.

NOTE: Step 2 can be done as many times as required. And relative
paths can be given here.

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>

CMakeLists.txt

@@ -776,7 +776,9 @@ if(CONFIG_APPLICATION_MEMORY)
 	)
 endif() # CONFIG_APPLICATION_MEMORY
 
-
+if (CONFIG_CODE_DATA_RELOCATION)
+  set(CODE_RELOCATION_DEP code_relocation_source_lib)
+endif() # CONFIG_CODE_DATA_RELOCATION
 
 construct_add_custom_command_for_linker_pass(linker custom_command)
 add_custom_command(
@@ -788,6 +790,7 @@ add_custom_target(
   DEPENDS
   ${ALIGN_SIZING_DEP} ${PRIV_STACK_DEP}
   ${APP_SMEM_DEP}
+  ${CODE_RELOCATION_DEP}
   linker.cmd
   offsets_h
   )
@@ -851,6 +854,28 @@ if(CONFIG_GEN_ISR_TABLES)
   set_property(GLOBAL APPEND PROPERTY GENERATED_KERNEL_SOURCE_FILES isr_tables.c)
 endif()
 
+if(CONFIG_CODE_DATA_RELOCATION)
+   set(MEM_RELOCATAION_LD "${PROJECT_BINARY_DIR}/include/generated/linker_relocate.ld")
+   set(MEM_RELOCATAION_CODE "${PROJECT_BINARY_DIR}/code_relocation.c")
+
+   add_custom_command(
+     OUTPUT ${MEM_RELOCATAION_CODE} ${MEM_RELOCATAION_LD}
+     COMMAND
+     ${PYTHON_EXECUTABLE}
+     ${ZEPHYR_BASE}/scripts/gen_relocate_app.py
+     $<$<BOOL:${CMAKE_VERBOSE_MAKEFILE}>:--verbose>
+     -d ${APPLICATION_BINARY_DIR}
+     -i '$<TARGET_PROPERTY:code_data_relocation_target,COMPILE_DEFINITIONS>'
+     -o ${MEM_RELOCATAION_LD}
+     -c ${MEM_RELOCATAION_CODE}
+     DEPENDS app kernel ${ZEPHYR_LIBS_PROPERTY}
+     )
+
+   add_library(code_relocation_source_lib  STATIC ${MEM_RELOCATAION_CODE})
+   target_link_libraries(code_relocation_source_lib zephyr_interface)
+
+endif()
+
 if(CONFIG_ARM AND CONFIG_USERSPACE)
   set(GEN_PRIV_STACKS $ENV{ZEPHYR_BASE}/scripts/gen_priv_stacks.py)
   set(PROCESS_PRIV_STACKS_GPERF $ENV{ZEPHYR_BASE}/scripts/process_gperf.py)
@@ -1138,6 +1163,7 @@ if(CONFIG_CPU_HAS_MPU AND CONFIG_USERSPACE)
       linker_app_sizing.cmd
       offsets_h
       ${APP_SMEM_DEP}
+      ${CODE_RELOCATION_DEP}
     )
 
     set_property(TARGET
@@ -1152,9 +1178,9 @@ if(CONFIG_CPU_HAS_MPU AND CONFIG_USERSPACE)
     # other ELF files are built
     set(GEN_APP_ALIGN $ENV{ZEPHYR_BASE}/scripts/gen_alignment_script.py)
     add_executable(       app_sizing_prebuilt misc/empty_file.c)
-    target_link_libraries(app_sizing_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker_app_sizing.cmd ${zephyr_lnk})
+    target_link_libraries(app_sizing_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker_app_sizing.cmd ${zephyr_lnk} ${CODE_RELOCATION_DEP})
     set_property(TARGET   app_sizing_prebuilt PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker_app_sizing.cmd)
-    add_dependencies(     app_sizing_prebuilt linker_app_sizing_script offsets )
+    add_dependencies(     app_sizing_prebuilt linker_app_sizing_script offsets ${CODE_RELOCATION_DEP} )
 
     add_custom_command(
       TARGET app_sizing_prebuilt
@@ -1177,6 +1203,7 @@ if(CONFIG_ARM)
     linker_priv_stacks_script
     DEPENDS
     ${ALIGN_SIZING_DEP} ${APP_SMEM_DEP}
+    ${CODE_RELOCATION_DEP}
     linker_priv_stacks.cmd
     offsets_h
     )
@@ -1189,7 +1216,7 @@ if(CONFIG_ARM)
 
   set(PRIV_STACK_LIB priv_stacks_output_obj_renamed_lib)
   add_executable(       priv_stacks_prebuilt misc/empty_file.c)
-  target_link_libraries(priv_stacks_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker_priv_stacks.cmd ${zephyr_lnk})
+  target_link_libraries(priv_stacks_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker_priv_stacks.cmd ${zephyr_lnk} ${CODE_RELOCATION_DEP})
   set_property(TARGET   priv_stacks_prebuilt PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker_priv_stacks.cmd)
   add_dependencies(     priv_stacks_prebuilt ${ALIGN_SIZING_DEP} linker_priv_stacks_script offsets)
 endif()
@@ -1198,7 +1225,7 @@ endif()
 
 # FIXME: Is there any way to get rid of empty_file.c?
 add_executable(       zephyr_prebuilt misc/empty_file.c)
-target_link_libraries(zephyr_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker.cmd ${PRIV_STACK_LIB} ${zephyr_lnk})
+target_link_libraries(zephyr_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker.cmd ${PRIV_STACK_LIB} ${zephyr_lnk} ${CODE_RELOCATION_DEP})
 set_property(TARGET   zephyr_prebuilt PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker.cmd)
 add_dependencies(     zephyr_prebuilt ${ALIGN_SIZING_DEP} ${PRIV_STACK_DEP} linker_script offsets)
 
@@ -1218,6 +1245,7 @@ if(GKOF OR GKSF)
     linker_pass_final_script
     DEPENDS
     ${ALIGN_SIZING_DEP} ${PRIV_STACK_DEP}
+    ${CODE_RELOCATION_DEP}
     zephyr_prebuilt
     linker_pass_final.cmd
     offsets_h
@@ -1229,7 +1257,7 @@ if(GKOF OR GKSF)
   )
 
   add_executable(       kernel_elf misc/empty_file.c ${GKSF})
-  target_link_libraries(kernel_elf ${GKOF} ${TOPT} ${PROJECT_BINARY_DIR}/linker_pass_final.cmd ${zephyr_lnk})
+  target_link_libraries(kernel_elf ${GKOF} ${TOPT} ${PROJECT_BINARY_DIR}/linker_pass_final.cmd ${zephyr_lnk} ${CODE_RELOCATION_DEP})
   set_property(TARGET   kernel_elf PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker_pass_final.cmd)
   add_dependencies(     kernel_elf ${ALIGN_SIZING_DEP} ${PRIV_STACK_DEP} linker_pass_final_script)
 else()

cmake/app/boilerplate.cmake

@@ -62,6 +62,8 @@ set(__build_dir ${CMAKE_CURRENT_BINARY_DIR}/zephyr)
 
 set(PROJECT_BINARY_DIR ${__build_dir})
 
+add_custom_target(code_data_relocation_target)
+
 # CMake's 'project' concept has proven to not be very useful for Zephyr
 # due in part to how Zephyr is organized and in part to it not fitting well
 # with cross compilation.

cmake/extensions.cmake

@@ -692,6 +692,14 @@ function(zephyr_check_compiler_flag lang option check)
   endif()
 endfunction()
 
+# Helper function for CONFIG_CODE_DATA_RELOCATION
+# Call this function with 2 arguments file and then memory location
+function(zephyr_code_relocate file location)
+  set_property(TARGET code_data_relocation_target
+    APPEND PROPERTY COMPILE_DEFINITIONS
+    "${location}:${CMAKE_CURRENT_SOURCE_DIR}/${file}")
+endfunction()
+
 ########################################################
 # 2. Kconfig-aware extensions
 ########################################################