Eric,
I am sorry that I did not provide enough information.
1.The PC is regarded as the PCIE RC, and the PCIE EP is a customized board.(The customized board is designed similar to 6678 EVM, and the procedure works well when 6678EVM works as PCIE EP).
2.The boot mode is PCIE.
SW3: (off, on, on, off)
SW4: (on, on, on, on)
SW5: (on, on, on, off)
SW6: (off, on, on, on)
SW9: (off, on,on,on)
3.RC can write successfully to EP.
4.The read fails, because there is a file wirte in the procedure, and the file is null.