Does anyone know how I can spoof a CPUID? \ VOGONS

Does anyone know how I can spoof a CPUID?

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First post, by Duffman

Posted on 2025-01-20, 06:38

Duffman Offline

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Rank: Oldbie
Posts: 611
Joined: 2002-12-05, 05:20

Hi,

Does anyone know how I can spoof a CPUID?

I think nvidia's driver doesn't like working with Vortex86 CPUs since it's not expecting the 'Vortex86 SoC' VendorID or it's Family 6 Model 1 Stepping 1 designation and expects more common Intel or AMD configurations.

So, does anyone know how I can spoof the CPUID?

MB: ASRock B550 Steel Legend
CPU: Ryzen 9 5950X
RAM: Corsair 64GB Kit (4x16GB) DDR4 Veng LPX C18 4000MHz
SSDs: 2x Crucial MX500 1TB SATA + 1x Samsung 980 (non-pro) 1TB NVMe SSD
OSs: Win 11 Pro (NVMe) + WinXP Pro SP3 (SATA)
GPU: RTX2070 (11) GT730 (XP)

Reply 1 of 2, by jmarsh

Posted on 2025-01-20, 06:48

jmarsh Offline

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Joined: 2014-01-04, 09:17

Not easy unless the target program is running under a VM. CPUID is a non-privileged opcode, meaning any ordinary code can execute it without needing to use a syscall or triggering an exception. It's also only a 2-byte opcode so patching it to a branch is difficult; best you can do is patch it to an invalid opcode and somehow hook the exception handler for that.

Reply 2 of 2, by Duffman

Posted on 2025-01-20, 09:25

Duffman Offline

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Rank: Oldbie
Posts: 611
Joined: 2002-12-05, 05:20

Damn!
I need this on real hardware to test nvidia cards.

I guess I can't spoof the CPUID then.

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