Wake-On-LAN issue T420 BIOS reflash

[hoker]

I'm having some real trouble flashing coreboot on my Thinkpad T420 with my raspberry pi. I have the pi installed with everything I need, and flashrom is indeed working, however, it is unable to read the BIOS chip on my motherboard for obvious reasons. I am trying to use the "wake-on-lan" trick to supply power to the chip for flashing. The motherboard, with AC and Ethernet connected, does power up, with LED indicators by the LAN port flashing, but it only does so for a few seconds before turning off. I would ideally like to get the wake-on-lan method of power delivery working as it seems the most reliable on these machines, but I'm at a loss as to how to achieve this.

I had also tried direct power delivery to the chip from the 3.3V VCC pin-out on the raspberry pi, but every time I would connect my SIOC clip to the motherboard it would reboot my pi. The pi would also refuse to power on if the clip with VCC connected was attached to the BIOS chip, so if someone knows how to get this method of power delivery working, that would be just as great as figuring out the issue with the wake-on-lan approach.

Any help is much appreciated as this is my first BIOS re-flash project