ROM.CAB BIOS Editing?

[SiliconAngel]

Hello,

I have an HP 4510s with firmware F.20 installed. Unfortunately having this latest firmware installed is a little problematic as it can't be rolled back and performs checks against a signature before HPQFLASH will update the BIOS.

I have upgraded the PCI Express Mini wifi card in the notebook and of course need to get around the whitelist. I'm quite happy to simply replace the original card's harware ID with the new one and I believe I've been able to do that successfully using EZH20 and WinHEX. The problem is, now I've saved my ROM.BIN file, I can't actually flash it to the notebook, because HPQFLASH requires the original ROM.CAB file, and there's no way that I can think of to create a CAB file that will meet the signature check.

So am I doing something wrong? Is there some way to work around this?

Thanks in advance for your help,

Trevor

EDIT: Sorry if this isn't the correct sub-forum for my question, but I wasn't sure which would be better so put it here as it is whitelist related

[SiliconAngel]

Is this a dead forum, then?

I've managed to find this post by TTAV134, someone who seems to have done a lot of work on whitelist removal BIOS rewriting a couple of years ago, but hasn't posted anything since 2011. Anyway, it seems it is possible to modify the BIOS, but there is a check being performed by all current HP notebooks to determine if the BIOS is valid and genuine, and if not the device stops working.

This leads me to a couple of conclusions - either the BIOS can be modified to stop checking validity/legitimacy of installed BIOS firmware, or for devices that originally had BIOS firmware that didn't perform these checks there needs to be some way to roll back to a previous version.

My personal circumstance with the Probook 4510s means only the latest F.20 firmware implements these checks and prevents roll-back - none of the previous BIOS versions performed such checks or prevented roll-back to previous BIOS versions.

So does anyone know of a way to successfully reflash an older Firmware version to this (or similar HP) laptop?