Use find_program for compiler and tools search.

That brings Windows support.

cmake/stm32/common.cmake

@@ -20,11 +20,11 @@ set(TOOLCHAIN_BIN_PATH "${STM32_TOOLCHAIN_PATH}/bin")
 set(TOOLCHAIN_INC_PATH "${STM32_TOOLCHAIN_PATH}/${STM32_TARGET_TRIPLET}/include")
 set(TOOLCHAIN_LIB_PATH "${STM32_TOOLCHAIN_PATH}/${STM32_TARGET_TRIPLET}/lib")
 
-SET(CMAKE_OBJCOPY "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-objcopy" CACHE INTERNAL "objcopy tool")
-SET(CMAKE_OBJDUMP "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-objdump" CACHE INTERNAL "objdump tool")
-SET(CMAKE_SIZE "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-size" CACHE INTERNAL "size tool tool")
-SET(CMAKE_DEBUGGER "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-gdb" CACHE INTERNAL "debugger tool")
-SET(CMAKE_CPPFILT "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-c++filt" CACHE INTERNAL "C++filt tool")
+find_program(CMAKE_OBJCOPY NAMES ${STM32_TARGET_TRIPLET}-objcopy PATHS ${TOOLCHAIN_BIN_PATH})
+find_program(CMAKE_OBJDUMP NAMES ${STM32_TARGET_TRIPLET}-objdump PATHS ${TOOLCHAIN_BIN_PATH})
+find_program(CMAKE_SIZE NAMES ${STM32_TARGET_TRIPLET}-size PATHS ${TOOLCHAIN_BIN_PATH})
+find_program(CMAKE_DEBUGGER NAMES ${STM32_TARGET_TRIPLET}-gdb PATHS ${TOOLCHAIN_BIN_PATH})
+find_program(CMAKE_CPPFILT NAMES ${STM32_TARGET_TRIPLET}-c++filt PATHS ${TOOLCHAIN_BIN_PATH})
 
 include(stm32/f4)
 include(stm32/linker)

cmake/stm32_gcc.cmake

@@ -4,6 +4,6 @@ list(APPEND CMAKE_MODULE_PATH ${STM32_CMAKE_DIR})
 include(stm32/common)
 
 set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
-set(CMAKE_C_COMPILER "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-gcc")
-set(CMAKE_CXX_COMPILER "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-g++")
-set(CMAKE_ASM_COMPILER "${TOOLCHAIN_BIN_PATH}/${STM32_TARGET_TRIPLET}-gcc")
+find_program(CMAKE_C_COMPILER NAMES ${STM32_TARGET_TRIPLET}-gcc PATHS ${TOOLCHAIN_BIN_PATH})
+find_program(CMAKE_CXX_COMPILER NAMES ${STM32_TARGET_TRIPLET}-g++ PATHS ${TOOLCHAIN_BIN_PATH})
+find_program(CMAKE_ASM_COMPILER NAMES ${STM32_TARGET_TRIPLET}-gcc PATHS ${TOOLCHAIN_BIN_PATH})