Talos II/Recovering corrupt U-boot via Serial Port

Serial port recovery of U-Boot:

This method was discovered by Centurion Dan as an alternative to pulling and reflashing the BMC SPI chip after a failed update had corrupted/wiped U-Boot

Tools required:

- BMC serial port

- An x86 computer with a serial port (usb to serial works fine) - preferably running linux.

Software: [Proprietary] SOC Flash Utility from Aspeed Technology's Support Page: at least version 1.18.00

BMC Firmware bundle: Talos_II/Firmware Firmware BMC System Package 1.06 2a92dec044239591244b6ed69c3fac162a6b9ea4

Procedure:

1) Unzip the SOC FLASH Utility on your other computer, and unzip the appropriate SOC Flash Utility bundle for that computer.

2) Extract the BMC firmware bundle.

3) Run the following command ./socflash -s option=u comport="4" cs=0 if=image-u-boot gpio_b=S71 gpio_a=S70 option=f

- You can drop the option=f for a slower but verified write process

- if your serial interface can handle the baudrate 921600 add the parameter: baudrate=921600

- if you want to see what is going on, you can strace it by prepending: strace -e trace=open,close,read,write to the command above.

4) Be Patient: it took me about 45 minutes to complete the flash process.

Notes: - gpio_b=S71 and gpio_a=S70 are used to turn of the fpga watchdog timer before the flash process and then re-enables it after it's completed.