Dell Latitude XT3 - UEFI variables not working

[nkp123]

Hello ^^

I am modding mine Dell Latitude XT3 - new SSD, eGPU, maybe new CPU (in the far future).

I made my own DIY expresscard adapter for eGPU and everything is running fine, but there are some issues with TOLUD (I workarounded this with DSDT override), PCI express starting with 1.1 settings (workarounded with "driver hack" described below) and primary display adapter settings - I must start laptop without eGPU plugged in - otherwise internal LCD won't work. Theoretically I can do all of these things in "the proper way" with changing hidden BIOS settings. Following this post I prepared my IFR file from setup section and extracted needed UEFI variables:

Setting: Primary Display, Variable: 0xB9[1] {05 09 B9 00 01 B1 01 B2 01}
	Option: Auto, Value: 0x3 {09 09 27 01 03 00 13 00 00}
	Option: IGFX, Value: 0x0 {09 09 B3 01 00 00 10 00 00}
	Option: PEG, Value: 0x1 {09 09 B4 01 01 00 10 00 00}
	Option: PCI, Value: 0x2 {09 09 B5 01 02 00 10 00 00}

Setting: Internal Graphics, Variable: 0xBB[1] {05 09 BB 00 01 C4 01 C5 01}
	Option: Auto, Value: 0x2 {09 09 27 01 02 00 13 00 00}
	Option: Disabled, Value: 0x0 {09 09 29 01 00 00 10 00 00}
	Option: Enabled, Value: 0x1 {09 09 28 01 01 00 10 00 00}
	
Setting: Max TOLUD, Variable: 0xC1[1] {05 09 C1 00 01 3F 01 40 01}
	Option: Dynamic, Value: 0x0 {09 09 41 01 00 00 13 00 00}
	Option: 1 GB, Value: 0x1 {09 09 4B 01 01 00 10 00 00}
	Option: 1.25 GB, Value: 0x2 {09 09 4A 01 02 00 10 00 00}
	Option: 1.5 GB, Value: 0x3 {09 09 49 01 03 00 10 00 00}
	Option: 1.75 GB, Value: 0x4 {09 09 48 01 04 00 10 00 00}
	Option: 2 GB, Value: 0x5 {09 09 47 01 05 00 10 00 00}
	Option: 2.25 GB, Value: 0x6 {09 09 46 01 06 00 10 00 00}
	Option: 2.5 GB, Value: 0x7 {09 09 45 01 07 00 10 00 00}
	Option: 2.75 GB, Value: 0x8 {09 09 44 01 08 00 10 00 00}
	Option: 3 GB, Value: 0x9 {09 09 43 01 09 00 10 00 00}
	Option: 3.25 GB, Value: 0xA {09 09 42 01 0A 00 10 00 00}
	
Setting: PEG0 - Gen X, Variable: 0xCD[1] {05 09 CD 00 01 75 02 76 02}
	Option: Auto, Value: 0x0 {09 09 06 00 00 00 13 00 00}
	Option: Gen1, Value: 0x1 {09 09 7D 02 01 00 00 00 00}
	Option: Gen2, Value: 0x2 {09 09 7E 02 02 00 00 00 00}

(I also checked other values such as SATA mode, Expresscharge etc. just to be sure I extracted everything correctly)

 

Unfortunately none of them (Primary Display, Internal Graphics, TOLUD and PCIe Gen) work. Expresscard slot with eGPU is still stuck at 1gen (without "driver hack" that can set it to 2gen, of course), TOLUD still seems to be Dynamic (when I plug eGPU less than 1 second after power on (before Dell logo) I don't need to do DSDT override, otherwise I need) and Primary Display still seems to be Auto (no internal graphics if eGPU is plugged in before power on).

setup_var command works - for example:

Setting: SATA Mode Selection, Variable: 0xFB[1] {05 09 FB 00 01 09 03 0A 03}
	Option: IDE, Value: 0x0 {09 09 0B 03 00 00 10 00 00}
	Option: AHCI, Value: 0x1 {09 09 0C 03 01 00 13 00 00}
	Option: RAID, Value: 0x2 {09 09 0D 03 02 00 10 00 00}

changes SATA mode just fine. Also values of non-working variables stays the same after reboot.

 

Am I missing something? Maybe some further BIOS unlocking is needed to change all of UEFI variables? Any help would be appreciated.

 

P.S. What "driver hack" is? I discovered that in my case (AMD FirePro V5800) reinstalling AMD driver through official AMD installer can reset PCIe port and it will work with gen2 speed until reboot.

 

Regards,

nkp123

Edited September 25, 2016 by nkp123
Described what 3rd party program is