1. How to use autotest. Just run auto_test under module_test dir. 'test_list' contain each module shell's name and parameter. if you run auto_test, it will run the shell of each line successively. What need to do when test each module. i2c: connect i2c1 tx and i2c2 rx, i2c2 rx and i2c1 tx. pcm/i2s: load corresponding module and connect it's tx and rx. uart: connect uart1 and uart 3. sd: insert an sd-card. usb: insert u-disc and create a 200M file named '200M.bin' in it. spi: load spi module DON'T COPY THE 'src' DIR TO THE TARGET!!!!