(UEFI) Dell XPS 15z L511z modded BIOS - and HOWTO

[jkbuha]

Thanks mate - appreciate you taking the time between your studies (which is definitely more important! ) I can do some work on my end if you'd just like to get me up to speed with what you've done in the meantime.

[jkbuha]

Hey Ahmed

Hope you're well. I have some time to work on the BIOS this week - have you made any additional developments on this since we last spoke?

Cheers
jkbuha

[jkbuha]

Hi Ahmed

Any updates from your end? I have some spare time in the next few weeks - would it be possible for the two of us to resume work on this soon?

There could be some developments by way of emulation - but it would be good to hear if you've had any further progress your end as well.

Cheers
jkbuha

[marstone]

hi, i'm new here, i got a xps l702x several days ago.
i use andy's tool inspected the bios, and found the architect is almost the same with xps 15.
i just wanna unlock the uefi boot/shell menus.
i'm new to bios mod/diassembly, andi wanna to get/do something help.
i read this thread carefully and appreciate all your works, thanks
i got a copy of TianoCore's open source from intel, and found that:

1.some .efi files are included and with the same GUID: such as PeiMain.efi(52C05B14-0B98-496C-BC3B-04B50211D680_1_1192.ROM)
2.some .efi files are included but without the same GUID, such as DxeMain.efi, Shell.efi
3.those most interesting files are all not included :-(
such as PlatformSetupAdvancedDxe.efi (CFEF94C4-4167-466A-8893-8779459DFA86_2_1063.ROM) and any other Setup related rom(SystemSetupMainDxe.efi, SystemSetupExitDxe.efi).
those file must be developed by phoenix(not intel)

I'v seen Tiano has an emulator, but the menu layout is much difference from ours. i'll ask & try whether the emulator can help run the modules.

[jkbuha]

Great to have you onboard

I actually have the CFEF...ROM file which is the one my 15z calls, but so far I haven't found a way around unlocking some of its menus.... my suspicion is that the menus are unlocked not thru nopping (90 90) the code, but setting a menu mask somewhere in the code.

Great news if we could use the Tiano emulator - please do let me know if you have any additional details on this!

Cheers
jkbuha

[AHMED HOSSAM]

Hi All ,

First , i`m so sorry for my late response but i hadn`t any time for the forum the last period ....... quiz and exams comes one by one with no time for rest .
i have checked the BIOS several times since last time we have talked and modifying the code will not lead to anything .
some UEFI BIOSs got the advanced tab but its hidden , modifying the code in this case will work and make the advanced menu appear .
in your case , the advanced menu already found and no need to modify the code , the menus inside the advanced tab are hidden through something like flags ............. for example ,its like an if statement checking for bytes or flags : if it found a byte or flag with a special state , it will hide it , but if it found the opposite state , it will show the menu ....... its something like this and its impossible to findout how this works without simulation tool as we don`t even knew where these bits are found .
i`m afraid we are wasting our time without a simulation tool to findout where these bytes are found .
if we found emulator , we can modify and compare results then think and generate a general method for doing this , but till this tool appears we haven`t any chance for unlocking menus which aren`t hidden through codes .
@marstone : can you let us knew which tool you are using for simulation ! please upload it as this will greatly help us .

Thank you,
Ahmed

[marstone]

@Ahmed, @jkbuha:
very glad to hear u!

I got a good news and a bad.
the bad news is the emulator I seen an Intel(er) used is NT32: http://sourceforge.net/apps/mediawiki/ti...title=NT32
they said to me it will only support x86 32bit, but the module we tried to boot(PlatformSetupAdvancedDxe.efi, CFEF...ROM) is an DXE module,
in the UEFI boot phase, "DXE" runs in 64bit mode and will not be loaded.

I also asked another UEFI developer in IBM, he said there are 2 ways to debug UEFIs,
for hardware independent modules, they debug via COM by using specified hardware, which is much expensive;
the hardware dependent ones can be debugged in NT32.

the good news is I am trying to contacts some former Phoenix developers via my friend to see if they had some source code of PlatformSetupAdvancedDxe.efi, he will response on next Monday. I will post as soon as possible if i can get some source.


PS: I got another problem and need some help,
when i formatted my disk with GPT partition table, i got the error message: "Operation System not found"
I check both my legacy MBR & partition boot records, there is nothing wrong and no such "string",
Then I realized that this would be something wrong in the BIOS
(the spell of the msg is wrong, It should be "Operating System" rather than "Operation System")
I search the string in F33E...ROM DUMP and finally found it in 1547B4F3....ROM, which is "freeform" in andy's tool.
then I Googled the problem, and it is said to be a bug of xps 15z/l502x/l702x BIOS

That's to say: The Phoenix Tiano BIOS really support "GPT" as it boots in a UEFI style.
however, I wanna know how to fix it? i just can not boot any thing in GPT disk.
shall we hack it by ignore "GPT" and let it boots just like a real legacy BIOS?
or shall we add something to the disk/partitions and let it BOOT as the real UEFI? (any way, unlock the hidden menus is the best way - -#)
are you all use MBR? any work around if i insist to use "GPT"...

Thanks!

[jkbuha]

Sounds like we're making progress here! Do let us know if your Phoenix/IBM contacts can give us any help on the UEFI debugging. As Ahmed said, we've tried a number of times to reset the masks on the bios menus, but the only thing we managed to do so far is disable the Advanced menu, so the next steps must be simulation and/or realtime debugging.

I had the same problem re: GPT - the only real fix seems to be (i) Dell fix their rubbish source code to boot from GPT disks (ii) we patch in another functioning GPT module. Unless anyone else has any other ideas...

[jkbuha]

Hey marstone - any feedback from your IBM/Phoenix contacts?

Would be good to see if there is a way of debugging in NT32/64

[ArthurianX]

This is a noobish question:

I can't find a winflash that works. (I get the 16bit error, system not supported), I ran it under Windows 7 x64 Ult.
I also tried with the method from this PHOENIX Thread, but it says "platform signature not found in the signature".

Can someone please describe a flashing method that works or point out what am I doing wrong?

Thank you very much!