text: import os
  import sys
  
  # toolchains options
  ARCH='risc-v'
  CPU='hpmicro'
  CHIP_NAME='HPM6750'
  
  CROSS_TOOL='gcc'
  
  
  # bsp lib config
  BSP_LIBRARY_TYPE = None
  
  if os.getenv('RTT_CC'):
      CROSS_TOOL = os.getenv('RTT_CC')
  
  # cross_tool provides the cross compiler
  # EXEC_PATH is the compilercute path, for example, CodeSourcery, Keil MDK, IAR
  if  CROSS_TOOL == 'gcc':
      PLATFORM    = 'gcc'
      if os.getenv('RTT_RISCV_TOOLCHAIN'):
          EXEC_PATH = os.getenv('RTT_RISCV_TOOLCHAIN')
      else:
          EXEC_PATH   = r'/opt/riscv-gnu-gcc/bin'
  else:
      print("CROSS_TOOL = {} not yet supported" % CROSS_TOOL)
  
  
  
  BUILD = 'flash_debug'
  
  if PLATFORM == 'gcc':
      PREFIX = 'riscv64-unknown-elf-'
      CC = PREFIX + 'gcc'
      CXX = PREFIX + 'g++'
      AS = PREFIX + 'gcc'
      AR = PREFIX + 'ar'
      LINK = PREFIX + 'gcc'
      GDB = PREFIX + 'gdb'
      TARGET_EXT = 'elf'
      SIZE = PREFIX + 'size'
      OBJDUMP = PREFIX + 'objdump'
      OBJCPY = PREFIX + 'objcopy'
      STRIP = PREFIX + 'strip'
  
      DEVICE = ' -std=c99 -DUSE_NONVECTOR_MODE=1'
      ARCH_ABI = ' -march=rv32imac -mabi=ilp32 -mcmodel=medlow '
      CFLAGS = DEVICE + ARCH_ABI + ' -ffunction-sections -fdata-sections -fno-common'
      AFLAGS = CFLAGS
      LFLAGS  = ARCH_ABI + ' --specs=nosys.specs -nostartfiles -Wl,--gc-sections '
  
      CPATH = ''
      LPATH = ''
  
      if BUILD == 'ram_debug':
          CFLAGS += ' -gdwarf-2'
          AFLAGS += ' -gdwarf-2'
          CFLAGS += ' -O0'
          LFLAGS += ' -O0'
          LINKER_FILE = 'board/linker_scripts/ram_rtt.ld'
      elif BUILD == 'ram_release':
          CFLAGS += ' -O2 -Os'
          LFLAGS += ' -O2 -Os'
          LINKER_FILE = 'board/linker_scripts/ram_rtt.ld'
      elif BUILD == 'flash_debug':
          CFLAGS += ' -gdwarf-2'
          AFLAGS += ' -gdwarf-2'
          CFLAGS += ' -O0'
          LFLAGS += ' -O0'
          CFLAGS += ' -DFLASH_XIP=1'
          LINKER_FILE = 'board/linker_scripts/flash_rtt.ld'
      elif BUILD == 'flash_release':
          CFLAGS += ' -O2 -Os'
          LFLAGS += ' -O2 -Os'
          CFLAGS += ' -DFLASH_XIP=1'
          LINKER_FILE = 'board/linker_scripts/flash_rtt.ld'
      else:
          CFLAGS += ' -O2 -Os'
          LFLAGS += ' -O2 -Os'
          LINKER_FILE = 'board/linker_scripts/ram_rtt.ld'
      LFLAGS += ' -T ' + LINKER_FILE
  
      POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
  
      # module setting
      CXXFLAGS = ' -Woverloaded-virtual -fno-exceptions -fno-rtti '
      M_CFLAGS = CFLAGS + ' -mlong-calls -fPIC '
      M_CXXFLAGS = CXXFLAGS + ' -mlong-calls -fPIC'
      M_LFLAGS = DEVICE + CXXFLAGS + ' -Wl,--gc-sections,-z,max-page-size=0x4' +\
                                      ' -shared -fPIC -nostartfiles -static-libgcc'
  