tweaking Nvidia Kepler/Maxwell rom on linux

ut0ugh1 · 04-01-2016, 02:02 PM

With nvflash I have backed up my Evga GT 710, now I need some help to tweak the rom on linux so no Nbitiror, kepler or maxwell vbios tweaker. I binwalked the rom but it only extracted the pem certificate,

Code:

binwalk -ev EVGAGT710_2GB.rom 
Scan Time:     2016-04-01 21:40:14
Target File:   EVGAGT710_2GB.rom
MD5 Checksum:  85013e0cdb0956220bda81932b5f7902
Signatures:    285

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
1777          0x6F1           Copyright string: " (C) 1996-2015 NVIDIA Corp."
167024        0x28C70         PEM certificate
168053        0x29075         PEM certificate


file _EVGAGT710_2GB.rom.extracted/2*
_EVGAGT710_2GB.rom.extracted/28C70.crt: PEM certificate
_EVGAGT710_2GB.rom.extracted/29075.crt: PEM certificate

Has anyone an idea?

mostlyharmless · 04-01-2016, 04:53 PM

What are you trying to accomplish, exactly, other than bricking your graphics card? There are information resources, for example, on "Quadrifying" Nvidia gaming cards, including using a soldering iron. Then there are pages devoted to loading different roms while using a VM.

ut0ugh1 · 04-01-2016, 07:38 PM

I would try to modify the rom directly on linux (without Window cause I have no images) and then flashing back onto the graphic card to push it up to the max I can. Not trying to make a quadro versiono of my gt710 soldering a any Xohm resistor. And thanks for the replies.

mostlyharmless · 04-02-2016, 10:42 AM

Most people seem to feel flashing roms not using Windows is somewhat hazardous, but I'm sure you know that and you have no Windows. One thing I would recommend is modifying the rom image and loading into a VM (so that the VM uses the image not its own ROM) for experimentation before trying to flash it to the card.

In terms of Linux tools for copying the rom, start with http://vfio.blogspot.com/2014/08/doe...t-efi.html?m=1

Although the link is mostly about passthrough to a VM (which I recommend for experimentation) it gives some excellent tips on copying the contents. The vfio mailing list has had a number of people who have messed around with the roms in their cards: you might want to check out the list for previous efforts.

ut0ugh1 · 04-03-2016, 08:33 AM

Thanks for the support. With nvflash I obtained the rom from my evga gpu and rom-parser

Code:

rom-parser EVGAGT710_2GB.rom 
Valid ROM signature found @600h, PCIR offset 190h
	PCIR: type 0 (x86 PC-AT), vendor: 10de, device: 128b, class: 030000
	PCIR: revision 0, vendor revision: 1
Valid ROM signature found @fc00h, PCIR offset 1ch
	PCIR: type 3 (EFI), vendor: 10de, device: 128b, class: 030000
	PCIR: revision 3, vendor revision: 0
		EFI: Signature Valid, Subsystem: Boot, Machine: X64
	Last image

Code:

hp@hp-desktop:~$ lspci -nn -vv|grep NVIDIA
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK208 [GeForce GT 710] [10de:128b] (rev a1) (prog-if 00 [VGA controller])
01:00.1 Audio device [0403]: NVIDIA Corporation GK208 HDMI/DP Audio Controller [10de:0e0f] (rev a1)

So I've booted add amd_iommu=on for my Asrock FM2A75M-DGS with pci-stub.ids=10de:128b,10de:0e0f.

Then I run:

Code:

[root@hp-desktop 0000:01:00.0]# echo 1 > rom
[root@hp-desktop 0000:01:00.0]# cat rom > /tmp/image.rom
cat: rom: Input/output error
[root@hp-desktop 0000:01:00.0]# dmesg
....
[17386.105826] pci-stub 0000:01:00.0: Invalid ROM contents

Code:

hp@hp-desktop:~$ rom-parser image.rom 
Valid ROM signature found @0h, PCIR offset 190h
	PCIR: type 0 (x86 PC-AT), vendor: 10de, device: 128b, class: 030000
	PCIR: revision 0, vendor revision: 1
Error, ran off the end
hp@hp-desktop:~$ ./test_interrupt_remapping 
No interrupt remapping support found

Sorry but I did not understand which program can help me to change the vbios so that I can upload with nvflash back to the my EVGA.

mostlyharmless · 04-03-2016, 12:02 PM

Changing the vbios would involve a hex editor. Knowing what to change would involve more technical knowledge than I have. Uploading to your card, ie flashing the rom would probably involve booting a USB drive with a nvidia utility program running under FreeDOS: I don't think you can flash these guys with a native Linux binary.

As I said before, I'd experiment with loading the vbios in qemu for a VM prior to trying to flash it.