[coreboot] Flashing coreboot on T440p by just flashing the 4MB chip - how?

[Daniel Kulesz]

Hi folks,

I am trying to put coreboot on a T440p that runs the latest OEM Firmware from April 2020. According to the official coreboot documentation, it should be doable by just flashing the (easily accessible) 4MB chip. While I successfully extracted the OEM ROM from this 4 MB chip using an external programmer and obtained the mrc.bin as explained in coreboot's docs, I failed to build coreboot itself. The build fails because I don't have the other proprietary parts (descriptor.bin, me.bin, gbe.bin).

All reports I found extract the ROM from both the 4 MB and 8 MB chips, put them together, and then run ifdtool on it to obtain these parts. If I try running ifdtool on just the 4MB dump, I get the following:

~/coreboot/util/ifdtool$ ./ifdtool -x t440p_4mb.rom 
File t440p_4mb.rom is 4194304 bytes
Unknown descriptor version: 1

Also, I can't extract them using me_cleaner.

Are these parts supposed to be contained in coreboot's 3rdparty repos (where I can't find them)? Or do I need to disassemble the whole device to extract the ROM from the 8MB chip as well in order to obtain these parts using ifdtool? Or is this process meant the way that I should build coreboot without these parts and only flash the BIOS region, not touching them?

Thanks a lot in advance.

Cheers, Daniel