Because it's always good to check, I extracted the discrete GPU's vgabios rom from my G505s following method 3 ("Retrieval via Linux kernel") listed here: [1] I have no dGPU, and I assume that it was discovered that this produces a clean (correct) iGPU rom blob. Not that I wrote a '1' to the file first to enable reading, as noted here: [2] I compared the files using tkdiff in hexdump format. See attachments for the files.

Comparing the file that I extracted and pci1002,990b.rom from [3] (obtained via "./atombios.sh") they are definitely very similar, but there are many spots with discrepancies. The diff output is at the end of this email. Along the way I had to take the file from the patch and turn it back into a binary and then hexdump it with the same options to make sure they had the same formatting.

It was noted in [4] that there were some differences between the vgabios roms used for integrated GPUs in laptops with and without discrete ones, specifically with regard to supply voltage. Can anyone confirm that the version supplied via the patch is the one from laptops with a discrete GPU, and that what I have matches what would be expected for a dGPU-less laptop? Is there a hash of the rom itself somewhere to point to?

Sincerely,

    -Matt

Attachments:

extracted_vgabios.rom => the rom I extracted myself

extracted_vgabios.rom.txt => the result of "hexdump -C extracted_vgabios.rom"

pci1002,990b.rom.txt => the rom from the patch (received along with 6663 and 6665)

Checksums:

References:

[1] https://coreboot.coreboot.narkive.com/zEkIcuSS/ultimate-vgabios-extraction-new-working-way-for-amd-laptop-s-discrete-gpu

[2] https://www.coreboot.org/VGA_support

[3] http://dangerousprototypes.com/docs/Lenovo_G505S_hacking

[4] https://mail.coreboot.org/hyperkitty/list/coreboot@coreboot.org/thread/GZNWISLFHUTYN6C7RTWSQUMJIFOUHMED/

Diff results: