zephyr/cmake/target_toolchain.cmake

62 lines
2.7 KiB
CMake

# SPDX-License-Identifier: Apache-2.0
# No official documentation exists for the "Generic" value, except their wiki.
#
# https://gitlab.kitware.com/cmake/community/wikis/doc/cmake/CrossCompiling:
# CMAKE_SYSTEM_NAME : this one is mandatory, it is the name of the target
# system, i.e. the same as CMAKE_SYSTEM_NAME would have if CMake would run
# on the target system. Typical examples are "Linux" and "Windows". This
# variable is used for constructing the file names of the platform files
# like Linux.cmake or Windows-gcc.cmake. If your target is an embedded
# system without OS set CMAKE_SYSTEM_NAME to "Generic".
set(CMAKE_SYSTEM_NAME Generic)
# https://cmake.org/cmake/help/latest/variable/CMAKE_SYSTEM_PROCESSOR.html:
# The name of the CPU CMake is building for.
#
# https://gitlab.kitware.com/cmake/community/wikis/doc/cmake/CrossCompiling:
# CMAKE_SYSTEM_PROCESSOR : optional, processor (or hardware) of the
# target system. This variable is not used very much except for one
# purpose, it is used to load a
# CMAKE_SYSTEM_NAME-compiler-CMAKE_SYSTEM_PROCESSOR.cmake file,
# which can be used to modify settings like compiler flags etc. for
# the target
set(CMAKE_SYSTEM_PROCESSOR ${ARCH})
# https://cmake.org/cmake/help/latest/variable/CMAKE_SYSTEM_VERSION.html:
# When the CMAKE_SYSTEM_NAME variable is set explicitly to enable cross
# compiling then the value of CMAKE_SYSTEM_VERSION must also be set
# explicitly to specify the target system version.
set(CMAKE_SYSTEM_VERSION ${PROJECT_VERSION})
# We are not building dynamically loadable libraries
set(BUILD_SHARED_LIBS OFF)
if(NOT (COMPILER STREQUAL "host-gcc"))
include(${TOOLCHAIN_ROOT}/cmake/toolchain/${ZEPHYR_TOOLCHAIN_VARIANT}/target.cmake)
endif()
# The 'generic' compiler and the 'target' compiler might be different,
# so we unset the 'generic' one and thereby force the 'target' to
# re-set it.
unset(CMAKE_C_COMPILER)
unset(CMAKE_C_COMPILER CACHE)
# A toolchain consist of a compiler and a linker.
# In Zephyr, toolchains require a port under cmake/toolchain/.
# Each toolchain port must set COMPILER and LINKER.
# E.g. toolchain/llvm may pick {clang, ld} or {clang, lld}.
include(${TOOLCHAIN_ROOT}/cmake/compiler/${COMPILER}/target.cmake OPTIONAL)
include(${TOOLCHAIN_ROOT}/cmake/linker/${LINKER}/target.cmake OPTIONAL)
# Uniquely identify the toolchain wrt. it's capabilities.
#
# What we are looking for, is a signature definition that is defined
# like this:
# * Toolchains with the same signature will always support the same set
# of flags.
# It is not clear how this signature should be constructed. The
# strategy chosen is to md5sum the CC binary.
file(MD5 ${CMAKE_C_COMPILER} CMAKE_C_COMPILER_MD5_SUM)
set(TOOLCHAIN_SIGNATURE ${CMAKE_C_COMPILER_MD5_SUM})