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

[ryan_975]

I wanted to detail a few things that I've figured out. If I'm recovering any ground, please forgive me. Perhaps I'll fill in some gaps.

BIOS1.WPH that you find in the Winflash folder is NOT the image that gets flashed to the system. It's an EFI capsule. Winflash UEFI copies it into system memory, tells the firmware where it is and changes the boot type to indicate the system's firmware needs to be updated. Then Winflash reboots the system.

After rebooting, the firmware sees that an update has been requested, looks for the the EFI capsule and walks the firmware volume contained within it to see if anymore drivers need to be loaded. It finds two components, a raw section (F33E367F....) and a Dxe driver. That driver is the actual flash utility, and F33E367F... is the actual firmware image + EC code and platform data that's copied into the system's flash memory and embedded controller.


Hope you guys find that helpful.

[jkbuha]

Hey ryan - thanks for this. We had kinda figured it out (which is why F33E6... then decomposes into additional ROM modules) but no worries - we're all learning here!

What we still haven't figured out yet is how we can flash a BIOS.WPH file directly from USB on power-up. Just renaming the file doesn't seem to work, as the USB drive starts flashing, but BIOS isn't flashed.

Maybe renaming the F33E6 file to BIOS.WPH might work, but I've never tried it (yet). See if you have any luck with this?

[ryan_975]

Hey ryan - thanks for this. We had kinda figured it out (which is why F33E6... then decomposes into additional ROM modules) but no worries - we're all learning here!

What we still haven't figured out yet is how we can flash a BIOS.WPH file directly from USB on power-up. Just renaming the file doesn't seem to work, as the USB drive starts flashing, but BIOS isn't flashed.

Maybe renaming the F33E6 file to BIOS.WPH might work, but I've never tried it (yet). See if you have any luck with this?

I tried it, it didn't work.

[jkbuha]

I tried it, it didn't work.

Did you try googling for the full UEFI recovery process (remove battery, reinsert, press fn+f3 etc)? Not sure if there's anything that needs to be done to 'prepare the BIOS' before flashing from USB?

[ryan_975]

I tried it, it didn't work.

Did you try googling for the full UEFI recovery process (remove battery, reinsert, press fn+f3 etc)? Not sure if there's anything that needs to be done to 'prepare the BIOS' before flashing from USB?

I've tried various methods that I'd found, but Fn-F3 I hadn't seen before. Will try that out in a bit.

If all else fails, and even if not, I'll buy an SPI programmer and flash the chip directly

[jkbuha]

Apparently, you can successfully flash the UEFI bios if you format the usb in fat (not fat32), put minidos.sys, phlash16.exe (or phlash.exe - I dont remember which) and the BIOS.WPH file. That way the usb can 'mini-boot'. But you'd probably have to double check on the net (GIYF )

SPI? I thought the Dell mobo chips were surface mounted?

[ryan_975]

Apparently, you can successfully flash the UEFI bios if you format the usb in fat (not fat32), put minidos.sys, phlash16.exe (or phlash.exe - I dont remember which) and the BIOS.WPH file. That way the usb can 'mini-boot'. But you'd probably have to double check on the net (GIYF )

I've been trying everything I find online, including you're suggestion. I think I did find the method to iniitiate a recovery mode, though. If I unplug the system, then hold down the "End" key, plug the system in, and quickly release it, the system automatically turns on with power led flashing, and no backlight (normally it will come on, even though nothing is displayed). It'll read the USB drive. If I have no files on the drive it'll flash once, then nothing happens. It I put a file name BIOS.cap on the drive, it flashes for a longer period of time (relative to the size of the file).. then... nothing.

SPI? I thought the Dell mobo chips were surface mounted?

The flash chip is surface mounted, but it's a pretty good size and ought to be easy enough to remove... or attach wires to. I could then flash whatever I wanted and get results without the risk of not being able to recover... again.

[jkbuha]

hey ryan

any luck with the recovery?

[ryan_975]

I've made some progress, but still no dice.

I've managed to get the laptop to recognize a firmware volume (I extracted the first file volume section from {F33...}.rom).

Rename the extracted module to "BIOS.cap"
put it on a FAT32 USB drive (mine is a 4GB one)
unplug the laptop
plug in the USB stick
hold down the end key
plug the laptop back in and release the end key within a couple seconds


The laptop will turn on with power light flashing, start reading the BIOS.cap file Then it reboots, power light goes solid, and I get the Dell Splash screen. I can enter the setup and boot selection menu, but I can't get it past that point, and it won't save any changes I make in setup.

[NaHoW]

Hello,

I'm following this up. I have no knowledge but I also want to unlock my BIOS to be able to use the RAID capabilities of the chipset.
I have a Dell XPS l702x and I will test it when you find something.


Kind regards,

Simon