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

[jkbuha]

Guys just saw this now. Good luck kasar (remember your ESD straps )
Rep to both - even if it won't ultimately work. Stuff like this takes cohones....

[kasar]

oh sh1t!

I think the wires from the chip to the internal plug I added are already like 20 cm

well, I supose a way to be sure the stuff is working fine, would be to take 2 /3 backups before flash anything and hex compare them, if everything is good the dumps should be identical I guess

edit: thx jkbuha

ESD straps? ¿ what u mean?

@all is just me or the forums are deadly slow again? D:

[jkbuha]

ESD = Electrostatic discharge straps - to prevent static buildup and fry your mobo
But from the sound of things you're working in a humid environment, so no static

[TimeWalker]

ESD strap is an anti-static wrist strap. I have one around because I never actually believed you can kill electronics with static until I actually managed to do this .. completely by accident. A 200$ graphics card ...
Yeah, the redundant dump approach should be a proper way of troubleshooting.

Yeah the forums seem kind of slow .. I guess Wiz is implementing another server and redirecting traffic.

[kasar]

ah, ok yeah, I allways touch the chasis of one of my old desktop machines while I am going to do electronics stuff ^^

I also doenst wear shoes while I am at home

I think that also helps to keep myself discharged

[kasar]

ok, almost completed the cable.

but I need help to connect the four last wires


in one side I have



and the another side I have




in my port side, aparently.

3.3v line goes to VCC, WP, and HOLD.

and GND goes to GND obiusly

but I'm not sure how to connect the 4 important wires

on my port side I have

- DI (IO 0)
- CLK
- DO (IO 1)
- /CS

and at the programer cable in construction I have

/CE
/SCK
/SO
/SI



aparently in the schematic, it ask about the chip legs, so I think the correct join match would be something like this:


- DI (IO 0) --> /SI
- CLK --> /SCK
- DO (IO 1) --> /SO
- /CS --> /CE

is this correct?


programer cable process:

[TimeWalker]

- DI (IO 0) (Data Input) = SI (Serial Data Input)
- CLK (Serial Clock Input) = SCK
- DO (IO 1) (Data Output) = SO (Serial Data Output)
- /CS (Chip Select Input) = CE (Chip Enable)

Yes, correct @kasar

---

Zener diode in reverse bias is not really a good way of dropping the voltage down to 3.3 .. and the cable is waaay to long.
I would opt for a low-drop v-reg of some sort .. a TS1117CW-3.3 or a LD1117DT33 for example.. with a pair of 10uF tantalum caps to support it.

[kasar]

thanks timewalker

I will asemble the last conections of the programer and will test the conections with a multimeter.

I hope things goes fine ^^

---

well, as for the zenner diode, I didnt had any other options arround home.

all the electronics stores are far from home, I also had to get the printer port from another old project I wasnt using at all.

I checked the voltage with a multimeter and it output 3.40v

will it bring issues?

as for the cable, well, it would be nice to be able the printer port from my old laptop to the xps 15 internal programer port I added, and with the current size, they have to get really close :o

[TimeWalker]

Nah, should be fine. Besides while flashing the gain can go higher than 3.3, so having an extra is a good option.
I have an electronic store 2 minutes away just around the corner but man the components are pricey there .. I would rather drive to another part of the city and probably save more money (including gas) in the end ..

The length of the cable worries me though.. you can read properly but you may have issued while writing.. at least that what I had when I last reprogrammed my DIR-300..

Also please note that you can't probably directly dump, edit and flash the contents of the nand .. at least this is not the case on UEFI desktop boards. Service Tag, Express service code and a bunch of other DMI entries will be wiped, because these are just stored as variables which are pulled from somewhere to be initialized in the firmware. This may not necessarily be the case with our machines, but it's always good to take caution ...

[kasar]

ok, I completed the programer cable






well, like you said, the cable lenght plus the internal wiring I did yesterday on the laptop may be an issue, but well, lets cross fingers and see what we can do

mmm, what do you mean with I cant dump,edit, and flash?

I though by doing this we backup the whole content of the chip, including protected areas.

so, in case I dump, unlock the descriptor, and flash, should it work or it will lead problems?

anyway I think next step is test the cable by doing several dumps and comparing them, if they are identical then dumping method + cable + laptop internal wiring = good, if not, well, something went wrong ^^

I supose nothing can goes wrong by just dumping the chip content, right?