laks_dir = Dir('.')
ld_dir = Dir('ld_scripts')
main_sconscript = File('SConscript')

def select_arm(env, family):
	env.SetDefault(
		TOOLCHAIN = 'arm-none-eabi-',
	)
	
	if family == 'cortex-m4f':
		family = 'cortex-m4'
		has_mcu = True
	else:
		has_mcu = False
	
	env.Replace(
		CC     = '${TOOLCHAIN}gcc',
		CXX    = '${TOOLCHAIN}g++',
		AS     = '${TOOLCHAIN}gcc',
		LINK   = '${TOOLCHAIN}gcc',
		AR     = '${TOOLCHAIN}ar',
		RANLIB = '${TOOLCHAIN}ranlib',
		
		CCFLAGS   = Split('-O2 -Wall -ggdb -mcpu=${CPU_FAMILY} -mthumb -ffunction-sections'),
		CXXFLAGS  = Split('-std=gnu++11 -fno-exceptions -fno-rtti -Wno-pmf-conversions'),
		ASFLAGS   = Split('-c -x assembler-with-cpp -mcpu=${CPU_FAMILY} -mthumb'),
		LINKFLAGS = Split('-Wall -mcpu=${CPU_FAMILY} -mthumb -nostartfiles -Wl,-T${LINK_SCRIPT} -Wl,--gc-sections'),
		
		CPPPATH = [laks_dir],
		LIBPATH = [ld_dir],
		
		LIB_SOURCES = [],
		
		CPU_FAMILY = family,
	)
	
	if has_mcu:
		env.Append(CCFLAGS = Split('-mfloat-abi=hard -mfpu=fpv4-sp-d16'))
		env.Append(LINKFLAGS = Split('-mfloat-abi=hard -mfpu=fpv4-sp-d16'))
		env.Append(CPPDEFINES = ['HAS_FPU'])

def select_stm32(env, variant):
	family = variant[5:9]
	pin_count = variant[9]
	flash = variant[10]
	
	if family.startswith('f0'):
		select_arm(env, 'cortex-m0')
		env.Append(CPPDEFINES = ['STM32F0'])

		sram = family[2]
		
		env['LINK_SCRIPT'] = {
			('4', '6'): 'stm32_f04_6.ld',
			('5', '8'): 'stm32_f05_8.ld',
		}[sram, flash]
	
	elif family == 'f103':
		select_arm(env, 'cortex-m3')
		env.Append(CPPDEFINES = ['STM32F1'])
		
		env['LINK_SCRIPT'] = {
			'8': 'stm32_f1_8.ld',
			'b': 'stm32_f1_b.ld',
		}[flash]
	
	elif family == 'f303':
		select_arm(env, 'cortex-m4f')
		env.Append(CPPDEFINES = ['STM32F3'])
		
		env['LINK_SCRIPT'] = {
			'b': 'stm32_f303_b.ld',
			'c': 'stm32_f303_c.ld',
		}[flash]
	
	elif family == 'f373':
		select_arm(env, 'cortex-m4f')
		env.Append(CPPDEFINES = ['STM32F3'])
		
		env['LINK_SCRIPT'] = {
			'8': 'stm32_f373_8.ld',
			'b': 'stm32_f373_b.ld',
			'c': 'stm32_f373_c.ld',
		}[flash]
	
	elif family in ('f401'):
		select_arm(env, 'cortex-m4f')
		env.Append(CPPDEFINES = ['STM32F4'])
		
		env['LINK_SCRIPT'] = {
			'e': 'stm32_f401_e.ld',
		}[flash]
	
	elif family in ('f405', 'f407'):
		select_arm(env, 'cortex-m4f')
		env.Append(CPPDEFINES = ['STM32F4'])
		
		env['LINK_SCRIPT'] = {
			'e': 'stm32_f4_e.ld',
			'g': 'stm32_f4_g.ld',
		}[flash]
	
	elif family in ('l051', 'l052', 'l053'):
		select_arm(env, 'cortex-m0plus')
		env.Append(CPPDEFINES = ['STM32L0'])
		
		env['LINK_SCRIPT'] = {
			'8': 'stm32_l0_8.ld',
		}[flash]
	
	else:
		print('Unknown stm32 family: %s' % family)
		Exit(1)

def SelectMCU(env, mcu, variant_dir = None):
	mcu = mcu.lower()
	
	if mcu.startswith('stm32'):
		select_stm32(env, mcu)
	
	else:
		print('Unknown MCU: %s' % mcu)
		Exit(1)
	
	SConscript(main_sconscript, variant_dir = variant_dir, exports = 'env')

AddMethod(Environment, SelectMCU)

def Firmware(env, target, sources, **kwargs):
	objects = [env.Object(f) for f in Flatten([sources, env['LIB_SOURCES']])]
	firmware = env.Program(target, objects, **kwargs)
	#env.Depends(firmware, env['LINK_SCRIPT']) # TODO
	return firmware

AddMethod(Environment, Firmware)

# vim: syn=python