[Deprecated] Changing DVMT values in BIOS

[zogthegreat]

Hi everyone!

 

I just tried to do this on my Latitude E7250, with BIOS version A20 and I think that I might have messed up somewhere.

 

I followed the instructions and did the search for my DVMT and I found the following:

 

Spoiler

0x29261                 Setting: DVMT Pre-Allocated, Variable: 0x15B {05 91 BC 03 BD 03 7F 27 02 00 5B 01 14 10 01 3F 00}
0x29272                     Option: 32M, Value: 0x1 (default) {09 07 BE 03 10 00 01}
0x29279                     Option: 64M, Value: 0x2 {09 07 BF 03 00 00 02}
0x29280                     Option: 96M, Value: 0x3 {09 07 C0 03 00 00 03}
0x29287                     Option: 128M, Value: 0x4 {09 07 C1 03 00 00 04}
0x2928E                     Option: 160M, Value: 0x5 {09 07 C2 03 00 00 05}
0x29295                     Option: 192M, Value: 0x6 {09 07 C3 03 00 00 06}
0x2929C                     Option: 224M, Value: 0x7 {09 07 C4 03 00 00 07}
0x292A3                     Option: 256M, Value: 0x8 {09 07 C5 03 00 00 08}
0x292AA                     Option: 288M, Value: 0x9 {09 07 C6 03 00 00 09}
0x292B1                     Option: 320M, Value: 0xA {09 07 C7 03 00 00 0A}
0x292B8                     Option: 352M, Value: 0xB {09 07 C8 03 00 00 0B}
0x292BF                     Option: 384M, Value: 0xC {09 07 C9 03 00 00 0C}
0x292C6                     Option: 416M, Value: 0xD {09 07 CA 03 00 00 0D}
0x292CD                     Option: 448M, Value: 0xE {09 07 CB 03 00 00 0E}
0x292D4                     Option: 480M, Value: 0xF {09 07 CC 03 00 00 0F}
0x292DB                     Option: 512M, Value: 0x10 {09 07 CD 03 00 00 10}
0x292E2                     Option: 1024M, Value: 0x20 {09 07 CE 03 00 00 20}
0x292E9                     Option: 2016M, Value: 0x3F {09 07 CF 03 00 00 3F}
0x292F0                 End of Options {29 02}

 

0x29345                 Setting: DVMT Pre-Allocated, Variable: 0x15C {05 91 BC 03 BD 03 19 03 02 00 5C 01 10 10 01 10 00}
0x29356                     Option: 32M, Value: 0x1 (default) {09 07 BE 03 10 00 01}
0x2935D                     Option: 64M, Value: 0x2 {09 07 BF 03 00 00 02}
0x29364                     Option: 96M, Value: 0x3 {09 07 C0 03 00 00 03}
0x2936B                     Option: 128M, Value: 0x4 {09 07 C1 03 00 00 04}
0x29372                     Option: 160M, Value: 0x5 {09 07 C2 03 00 00 05}
0x29379                     Option: 192M, Value: 0x6 {09 07 C3 03 00 00 06}
0x29380                     Option: 224M, Value: 0x7 {09 07 C4 03 00 00 07}
0x29387                     Option: 256M, Value: 0x8 {09 07 C5 03 00 00 08}
0x2938E                     Option: 288M, Value: 0x9 {09 07 C6 03 00 00 09}
0x29395                     Option: 320M, Value: 0xA {09 07 C7 03 00 00 0A}
0x2939C                     Option: 352M, Value: 0xB {09 07 C8 03 00 00 0B}
0x293A3                     Option: 384M, Value: 0xC {09 07 C9 03 00 00 0C}
0x293AA                     Option: 416M, Value: 0xD {09 07 CA 03 00 00 0D}
0x293B1                     Option: 448M, Value: 0xE {09 07 CB 03 00 00 0E}
0x293B8                     Option: 480M, Value: 0xF {09 07 CC 03 00 00 0F}
0x293BF                     Option: 512M, Value: 0x10 {09 07 CD 03 00 00 10}
0x293C6                 End of Options {29 02}

 

0x293CA             Setting: DVMT Total Gfx Mem, Variable: 0x15D {05 91 D0 03 D1 03 1A 03 02 00 5D 01 10 10 01 03 00}
0x293DB                 Option: 128M, Value: 0x1 {09 07 D2 03 00 00 01}
0x293E2                 Option: 256M, Value: 0x2 {09 07 D3 03 00 00 02}
0x293E9                 Option: MAX, Value: 0x3 (default) {09 07 D4 03 10 00 03}
0x293F0             End of Options {29 02}

 

 

I choose the first value of 0x15B and ran the command. This was my output:

 

grub> setup_var 0x15B 0x3

Looking for Setup variable...

var name: Setup, var size: 12, var guid: ec87d643-eba4-4bb5 - a1-e5-3f-3e-36-b2-0d-a9

 

--> GUID does not match expected GUID, taking it nevertheless

expected a different size of the Setup variable (got 2638 (0xa4e) bytes). Continue with care...

successfully obtained "Setup" variable from VSS  (got 2638 (0xa4e) bytes).

offset 0x15B is: 0x01

setting offset 0x15b to 0x03

 

Is everything OK or do I have to dig out my SOC8 clip and programmer?  I'm attaching my extracted file.

 

Thanks!

 

zog

File_DXE_driver_Setup_SetupPrep IFR.7z

[Jake Lo]

that's fine. All it takes is a Load Default in the BIOs to set it all back.