So I have been attempting this for about 2-3 months, started with knowing almost nothing about bios modding to knowing quite a bit. I first started just trying to change NVRAM variables to unlock the hidden bios menus, but no such luck (I use linux so I cant just turn off OC locks and use XTU or Throttle stop, I did almost get somewhere modifying NVRAM with RU.efi ).
Started looking into BIOS modding and got to work on making one. I ended up with 4 versions of the mod, all made from my A16 Dump and a combo of a bunch of softwares (UEFI Editor V, Ghex, UEFI Tool, and UEFI Tool NE). I flashed all of them with a external programmer.
The first one just made my screen stay black and the wireless status light blinking. So I made sure to fix the ami protected ranges v1 hash file by putting the new calculated hash in, and tried it again (this being version 2 of the mod). This time i got a different light code, blinking wireless light, and solid battery, storage, and power light. I assumed that I had messed up something when creating the mod the first time so I restarted, same thing happened with the new 1 too (only tried the new Signed version of it, that being V4). But I was able to get the low level diagnostic running (D+Power button) on all 3 versions that I tried. As ive found out the ami protected ranges hash file is in the area the intel bootguard checks.
So there is 2 maybe 3 problems that I was not able to solve. #1 Disabling BIOS Signing Check. #2 Getting it to POST with the modded BIOS. #3 (the maybe) Fixing anything wrong with the modifications themselves. If anyone is willing to help or give advice on how to proceed with fixing the mod that would be greatly appreciated.
Note: DO NOT FLASH THE MODDED FILES UNLESS YOU HAVE AN EXTERNAL PROGRAMMER, THEY WILL BRICK YOUR DEVICE, THEY DO NOT WORK
This is a download to a folder with all the mods I made, plus a stable A25 bios pre split for external flashing to the chips, and the original dump
Link to the post I made on a different forum about my attempts to overclock via editing NVRAM
IIRC this machine has NO hidden menu to unlock. Yes there was some Debug entry or what in the IFR, but i’ve never been able to make it show. Maybe you can try sth like the Aptio V menu replace trick? I actually have no idea since this BIOS should be dell-customized Aptio IV.
And your another question about CPU OC. Just set 1-core to 4-core turbo ratio with nvram variables, and then you have nothing more to do. You cant actually unlock the power limit since it was most likely hardcoded or ec-controlled limited to 57W(non-MX CPU eg.4700MQ) or 67W(MX CPU eg.4930MX).
Last time i play with this model was about 7 or 8 years ago, please feel free to correct me if you find any of my mistake.
Yeah the first thing I tried was overclocking by editing NVRAM (I talk about that whole experience on the different forum post that I posted a link to), but since I was not able to get it to work correctly I kinda gave up on that. But since you say it works, what values did you change, if you remember of course. Also I will not be giving up on trying to get those menus yet, even if I end up at a dead end, still worth a shot
Dell Precision/Latitude laptops are nightmare to modify, because they are not using a “normal” AMI BIOS-es, but some kind of custom-made ones (of course Dell has to be different smh…). Your best bet is to use UEFITool 0.28 (because AMIBCP or MMTool wont work most of the time on Dell AMI IV BIOS, atleast that was in my case with Latitude e6540 years before) and find the “Setup” variable or anything that has the BIOS options and variables in it, then click “extract body” on the PE32 Image and save it in “setup.bin” file or whatever you like. After that, enter IFRExtractor via CMD and you will get a “.txt” file with “hidden” options that are not visible by default, with offsets (something like 0xABC, for example). Then, with USB Drive with “BOOTX64.efi” file in it, enter UEFI Shell and you should use commands like “setup_var” or something similar and find that offset you want to change it to something else… I dont exactly remmember to be honest, but there are guides online so it should be doable. I still have Dell Latitude e6540 with i7 4900MQ and AMD Radeon HD 8790M 2GB and that thing was really potent, but throttling as f. I even tried about 2-3 years ago with the same IFR route but with no success, so I gave up and I use it rarely as secondary PC. I remmember that with NimeZ drivers I could play Far Cry 5 on mixture of low/ultra (textures) settings @ 1366x768p - 25 to 35 fps, since HD 8790M is actually a pretty decent overclocker, but it throttled as hell as I said. Do you have CH341 programmer with you?