mikeb mikeb has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/31944 )
Change subject: G505S AtomBIOS ROMs: known good binaries with a script to check their SHA256 ......................................................................
Patch Set 2:
Repost of the important README.md parts from https://github.com/g505s-opensource-researcher/g505s-atombios :
# g505s-atombios AMD AtomBIOS video bios releases for G505S Integrated HD-8650G and discrete HD-8570M / R5-M230 GPUs
## Description
coreboot wiki describes 5 different ways of extracting the VGABIOS ROMs: https://www.coreboot.org/VGA_support#How_to_retrieve_a_good_video_bios And all these ways have been tried and found unsuitable for Lenovo G505S: https://mail.coreboot.org/pipermail/coreboot/2017-July/084660.html This message above - also describes a new method which really works!
Sadly this new method is Windows-only, but we believe it is a fine approach, because: two ROMs for integrated GPU, while got at these very different OS, are exactly the same - and most likely it is the same situation for discrete ROM Aside from purely ethical concerns, in practice it should not matter if you are using closed-source Windows instead of open-source Linux to extract the ROMs
But, to ensure that Windows could not receive the instructions from evil server to stealthily modify the extracted ROMs, these conditions should be fulfilled:
1) OS: clean install of Windows 7 Ultimate SP1 x64 without any spying updates (WiFi card removed before installation and OS never connected to the Internet) on a hard drive that has been securely formatted or never used by Windows before ^ same requirement for a media which you are using to bring the drivers/software
2) Proprietary UEFI/BIOS and KB9012 firmware: clean binaries flashed, (part of g505s-proprietary repository)* without any IDs or serial numbers
3)** After the extraction, the ROMs should be directly brought to Linux OS
All these conditions, as well as some others, have been fulfilled by us before the extraction of these ROMs. Please use Linux OS to download and make sure that their SHA-256 checksums are correct before using them
Turning ON/OFF the Dual Graphics before the extraction - does not affect any of these ROMs.
## coreboot.rom operations
Run ./cbfstool.sh script to download and build cbfstool, https://mail.coreboot.org/pipermail/coreboot/2017-July/084671.html [NOTE]: fix this script by adding a single '/' character after "--execute robots=off" at some lines, ===> "--execute robots=off "
Then use one of these commands:
1) Adding VGABIOS to coreboot.rom
./util/cbfstool/cbfstool $COREBOOT_ROM_PATH add -f $VGABIOS_PATH -n pci****,****.rom -t optionrom
2) Removing VGABIOS from coreboot.rom
./util/cbfstool/cbfstool $COREBOOT_ROM_PATH remove -n pci****,****.rom
3) Printing coreboot.rom memory map
./util/cbfstool/cbfstool $COREBOOT_ROM_PATH print