Merge topic 'renesas_compiler_toolchain_doc'

6139bb7903 Help: Document Renesas compiler toolchain

Acked-by: Kitware Robot <[email protected]>
Merge-request: !11446

Help/manual/cmake-toolchains.7.rst

@@ -723,3 +723,56 @@ For example, a toolchain file might contain:
   set(CMAKE_CXX_COMPILER /path/to/em++)
 
 .. _`Emscripten`: https://emscripten.org/
+
+Cross Compiling using Renesas compilers
+---------------------------------------
+
+For cross-compiling with Renesas compilers, specify at least:
+
+:variable:`CMAKE_SYSTEM_NAME`
+  Set to ``Generic``.  Must be specified to enable cross compiling.
+
+:variable:`CMAKE_C_COMPILER <CMAKE_<LANG>_COMPILER>`
+  Set to the path to the Renesas C compiler, e.g.,
+  ``ccrx``, ``ccrl``, or ``ccrh``.
+
+:variable:`CMAKE_C_FLAGS <CMAKE_<LANG>_FLAGS>`
+  Set to the ``-isa=`` or ``-cpu=`` flag the compiler requires.
+
+See example toolchain files in the following sections.
+
+Renesas CC-RX
+^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+  set(CMAKE_SYSTEM_NAME Generic)
+  set(CMAKE_C_COMPILER "ccrx.exe")
+  set(CMAKE_ASM_COMPILER "ccrx.exe") # if using ASM language
+  set(CMAKE_C_FLAGS "-isa=rxv3") # specify the version of target RX CPU
+  set(CMAKE_EXE_LINKER_FLAGS "-lnkopt=<your linker option here>")
+
+Renesas CC-RL
+^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+  set(CMAKE_SYSTEM_NAME Generic)
+  set(CMAKE_C_COMPILER "ccrl.exe")
+  set(CMAKE_ASM_COMPILER "ccrl.exe") # if using ASM language
+  set(CMAKE_C_FLAGS "-cpu=S3") # specify the version of target RL CPU
+  # To avoid test executable runs out of const section's size.
+  set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
+  # Specifying device file and section layout linker options through compiler driver.
+  set(CMAKE_EXE_LINKER_FLAGS "-lnkopt=-device=dr5f10y14.dvf -lnkopt=-auto_section_layout")
+
+Renesas CC-RH
+^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+  set(CMAKE_SYSTEM_NAME Generic)
+  set(CMAKE_C_COMPILER "ccrh.exe")
+  set(CMAKE_ASM_COMPILER "ccrh.exe") # if using ASM language
+  set(CMAKE_C_FLAGS "-Xcommon=rh850") # specify the version of target RH850 CPU
+  set(CMAKE_EXE_LINKER_FLAGS "-lnkopt=<your linker option here>")