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

[jkbuha]

Thanks Paralel and good sleuth work
If what you're saying is true then all we need is the latest 7.1.x firmware and the updated ME 8.x Win32/64 drivers?

[TimeWalker]

Nope, what he meant is that there are two firmwares for ME embedded at the same time. ME region is either split or there are two separate regions, one holds v7 fw, the other one v8. When a compatible IVB cpu is socketed the board knows this after a series of checks and therefore initiates proper ME and proper VBIOS (if any) to match the nested CPU. Our ME rom is just 1.5Mb in size, I've seen 5Mb roms around .. so this may explain why a split configuration with multiple firmwares is possible.

[kasar]

that makes sense, ME7 fw for sandy bridge and ME8 for ivy.

anyone know what is the max size of our rom chips, so if there is anyway we can have those 5mb firmwares on them?

or are we facing a firmware space limitation due hardware limitation?

[jkbuha]

That's a pity - but in reality I'm not that concerned with upgrading to an IVB processor.

I'm more interested in unlocking the overclocking & undervolting capabilities of our existing motherboards, which sounds like it can be done provided we find a way to enable r/w access to the descriptors first, most likely via a hotkey combo on bootup.

[Paralel]

That's a pity - but in reality I'm not that concerned with upgrading to an IVB processor.

I'm more interested in unlocking the overclocking & undervolting capabilities of our existing motherboards, which sounds like it can be done provided we find a way to enable r/w access to the descriptors first, most likely via a hotkey combo on bootup.

Actually, from going over the "System Tools User Guide", it should be possible for us to do what you want, at least as far as clock, directly in ME, without messing with the descriptors. But what we can do is directly limited by which chipset we have. From what I can tell, for the HM67, our overclocking potential is not great, but it is still possible.

Here are the various Intel PDF's I was able to pull together that I think may give us more information on what we need to do to accomplish what we want:

http://speedy.sh/qVrme/Cougar-Point-PDFs.zip

Worst comes to worst, it looks like we can use that Aardvark thing with a SODIMM connector to directly program it

As far as the ME7/ME8 hybrid here is a document that discusses it:

http://downloadmirror.intel.com/21483/en...eNotes.pdf

Note that before the notice about "structural" BIOS changes, the only ME listed are 7.X versions, but after that, they list both a 7.x AND 8.x versions for ME, supporting my Hybrid ME theory. If we can rip apart one of those BIOS updates for the desktop board, we may be able to figure out how they did it, and create our own Hybrid ME firmwares.

However, I fear, what they did was take two 1.5 MB versions, smash them together, and put them in a space formerly occupied by a 5 MB version of the 7.X firmware. If so, we have hit a hard dead end since our ME firmware space is only 1.5 MB, so, unless we could find some empty space somewhere and put a jump there to reference where the ME 8 Firmware is located elsewhere in the flash.

I have tried to flash a 5 MB version of the ME 7.x firmware, but it hits a fatal error of insufficient firmware space.

[TimeWalker]

That's some good info you've gathered, Paralel. I will try to read some of it during this weekend.

@jkbuha you have one of the steps covered incorrectly in the recovery procedure how-to.

Keep the <hotkey> sequence pressed, plug in the power cord back, and press the power button.

As soon as you plug in the power cord you let go of the <hotkey> and laptop should start automatically. You don't need to press the power button.
I wonder were you doing the same thing you describe during your attempts to initiate recovery? In case you were .. mind to try doing it the *right* way ?

[thorbsd]

That's some good info you've gathered, Paralel. I will try to read some of it during this weekend.

@jkbuha you have one of the steps covered incorrectly in the recovery procedure how-to.

Keep the <hotkey> sequence pressed, plug in the power cord back, and press the power button.

As soon as you plug in the power cord you let go of the <hotkey> and laptop should start automatically. You don't need to press the power button.
I wonder were you doing the same thing you describe during your attempts to initiate recovery? In case you were .. mind to try doing it the *right* way ?

I haven't attempted to flash anything on my XPS 15z, but when you:

unplug the power cord -> press and hold the right arrow key -> plug in the power cord -> remove finger from the right arrow key

the laptop powers up, and though the screen is black, the power button is illuminated and flashing (almost like it's sitting at a prompt waiting for some kind of input).

This does not work with any other key combination that I tried (other than holding down Fn and pushing the power button that takes you into the diagnostic mode)

[TimeWalker]

Then its a proper key to initiate the recovery as this is what's supposed to happen when crisis boot is triggered. Have you tried creating a capsule as explained in the OP and loading it of off the external media?

[jkbuha]

Guys sorry but either I'm really thick or my 15z is a bit different from the rest...

@thorbsd - just so I'm clear... on your 15z you press and hold the right arrow (which has End on it), plug in the power supply, and then release the key. The laptop powers on by itself?

[pierob]

@thorbsd - just so I'm clear... on your 15z you press and hold the right arrow (which has End on it), plug in the power supply, and then release the key. The laptop powers on by itself?

Unfortunately, my 15z not (i.e. it remains powered off). Tried with some other keys, same result. Hot sequence is still a mistery...