text: import os
  
  # toolchains options
  ARCH='arm'
  CPU='cortex-a'
  CROSS_TOOL='gcc'
  
  if os.getenv('RTT_CC'):
      CROSS_TOOL = os.getenv('RTT_CC')
  
  # only support GNU GCC compiler.
  PLATFORM  = 'gcc'
  EXEC_PATH = '/opt/gcc-arm-none-eabi-4_8-2014q1_gri/bin'
  
  if os.getenv('RTT_EXEC_PATH'):
      EXEC_PATH = os.getenv('RTT_EXEC_PATH')
  
  BUILD = 'debug'
  
  if PLATFORM == 'gcc':
      # toolchains
      PREFIX = 'arm-none-eabi-'
      CC = PREFIX + 'gcc'
      CXX = PREFIX + 'g++'
      AS = PREFIX + 'gcc'
      AR = PREFIX + 'ar'
      LINK = PREFIX + 'gcc'
      TARGET_EXT = 'elf'
      SIZE = PREFIX + 'size'
      OBJDUMP = PREFIX + 'objdump'
      OBJCPY = PREFIX + 'objcopy'
  
      DEVICE = ' -march=armv7-a -mtune=cortex-a9 -mfpu=vfpv3-d16 -ftree-vectorize -ffast-math -mfloat-abi=softfp'
      CFLAGS = DEVICE + ' -Wall'
      AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -D__ASSEMBLY__'
      LINK_SCRIPT = 'imx6.lds'
      LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread-imx6.map,-cref,-u,system_vectors'+\
                        ' -T %s' % LINK_SCRIPT
  
      CPATH = ''
      LPATH = ''
  
      # generate debug info in all cases
      AFLAGS += ' -gdwarf-2'
      CFLAGS += ' -g -gdwarf-2'
  
      if BUILD == 'debug':
          CFLAGS += ' -O0'
      else:
          CFLAGS += ' -O2'
  
      POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' +\
                    SIZE + ' $TARGET \n'
  