Since I updated the bios to 2.09 and meet many flaws. So I decieded to temporarily downgrade my edk2 firmware to 2.04. Because I cannot peform the downgrade via Capsule, I tried the following methods:
1. Try to switch booting bios to carriar bios (carriar bios can be easily re-programmed using a flash programmer eg. dediprog). But I just failed, No matter how I try setting JP27-JP29, the board always booting from the module bios.
2. Try to re-program the module bios using DB40 port. Since I can't find anywhere to buy the black version of DB40-HPC for A2 module, I try using a FPC to DIP converter and then connect it to a programmer:
Unfortunately, the definition of DB40 on A2 board is not included in the module's manual, and it is also not similar to any other board which have DB40 connector like below:
As of now, what I know is pin1 is SPI_VCC, pin7 is GND, and I also find pin15 is PWRBTN#, apparently not similar to any known document.
And I also can't determine the spi flash pins using a multimeter. (There's no direct connection between the SPI Flash chip and the DB40 connector).
So Who can help me provide the the definition of the DB40 connector of A2 board?
Thanks a lot.
At last resort, if there's no other option, I can only desolder the bios chip with my hot air gun, and re-program it using my programmer then solder it back. (I reluctant to try the last way, because it is too dangerous and will lost warranty.)