Help Needed With Flashing Modified Dell G5 5590 BIOS with Rebar Module

BIOS/UEFI Modding BIOS Modding Guides and Problems
1

Hello everyone,

I have decided to start learning how to modify my BIOS and I have succesfully managed to disable the overclocking lock on my Dell G5 5590 laptop after following a tutorial on youtube. After further digging I found out that my laptop’s GPU (1660ti) has support for Resizable Bar so I decided to look into enabling this where I came across ReBarUEFI and NVStrapsReBar and decided to start implementing this.

Normally, the BIOS does not have any option to enable Above 4G decoding. After examining my dumped bios and modifying it with grub I finally managed to get Above 4G Decoding to show up as enabled on GPU-Z and for Large Memory to show up in device manager

I have now inserted the ReBar Module into the dumped BIOS however I am stumped on figuring out how exactly I can now flash this. I have tried using Dell PFS Bios Assembler/Extractor to create a BIOS update file with the modified bios however I don’t think that’s compatible with my BIOS version (1.27.0) as it appears to be missing some things when extracted so I am unable to reassamble it back into an update file. I have also looked into using Flash Programming Tool but its not allowing me to write:

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I have thought about using a ch341 programmer to write to the bios chip itself but I do not have one on hand. Is there any other way to flash this modified bios onto my laptop?

2

Have you tried to short your motherboard service mode jumper?

3

I dont think my laptop has a jumper to enter service mode. I have had a look at the motherboard and I cannot find any information about this anywhere.

4

My bad, i thought it was a pc motherboard atm :joy::pray:t6:. I think you should use ch341a to dump the bios chip only and compare it with the fpt dump, to see if both dump have any differences before proceeding with flashing the bios.