arm-toolchain.cmake

# arm core is ARM7TDMI-S

set(CMAKE_SYSTEM_NAME Generic)

set(CMAKE_C_COMPILER arm-none-eabi-gcc)

set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)

#set(CMAKE_C_STANDARD 11)
#set(CMAKE_C_EXTENSIONS, TRUE)
#set(CMAKE_C_STANDARD_REQUIRED ON)

set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

set(ARCH_FLAGS "-g -mcpu=arm7tdmi-s -mthumb -masm-syntax-unified -mabi=aapcs")
# can help BOOT code size when using otherwise low opt level:
#   -fsection-anchors -mpic-data-is-text-relative
# -flto seems to break binary layout :/
# consider disabling auto inlining of small functions, etc
set(OPT_FLAGS "-O2 -ffunction-sections -fdata-sections -fomit-frame-pointer")
set(WARN_FLAGS "")
set(OBJ_FLAGS "${ARCH_FLAGS} ${OPT_FLAGS} ${WARN_FLAGS}")

set(CMAKE_C_FLAGS "${OBJ_FLAGS} -std=c99 -fsigned-char" CACHE INTERNAL "C Compiler options")
set(CMAKE_ASM_FLAGS "${ARCH_FLAGS}" CACHE INTERNAL "ASM Compiler options")

set(CMAKE_EXE_LINKER_FLAGS "--specs=nano.specs --specs=nosys.specs -Wl,--gc-sections -nostartfiles"
    CACHE INTERNAL "Linker options")