help on ThinkPad E550

[unacson]

My laptop is a Lenovo ThinkPad E550 with an i7-5500U processor, Intel HD5500 graphics and a 1920x1080 screen. I was able to install Yosemite by following [Guide] Booting the OS X installer on LAPTOPS with Clover with the config.plist for my graphics processor.

I can boot into that installation if I disable Intel Graphics injection, but then only 7mb of VRAM get recognized. If I leave Intel Injection enabled, I get a kernel panic before the logon screen. I've been reading this forum and I believe that now I should change the DVMT pre-allocation in UEFI. I extracted my BIOS and found that the corresponding variable is 0x37, and the value should be set to 0x4, but when I do this with the EFI Shell, all I get is a message "Looking for Setup variable..." and it does nothing else.

Has anyone gotten this computer working in Yosemite? I believe the E450 is very similar, that would be very useful too.

Thanks!

 

[RehabMan]

My laptop is a Lenovo ThinkPad E550 with an i7-5500U processor, Intel HD5500 graphics and a 1920x1080 screen. I was able to install Yosemite by following [Guide] Booting the OS X installer on LAPTOPS with Clover with the config.plist for my graphics processor.

I can boot into that installation if I disable Intel Graphics injection, but then only 7mb of VRAM get recognized. If I leave Intel Injection enabled, I get a kernel panic before the logon screen. I've been reading this forum and I believe that now I should change the DVMT pre-allocation in UEFI. I extracted my BIOS and found that the corresponding variable is 0x37, and the value should be set to 0x4, but when I do this with the EFI Shell, all I get is a message "Looking for Setup variable..." and it does nothing else.

Has anyone gotten this computer working in Yosemite? I believe the E450 is very similar, that would be very useful too.

Thanks!

Try going back to an older version of BIOS.

 

[unacson]

Try going back to an older version of BIOS.

Wow thanks for the quick answer. I'm already on the oldest BIOS (1.12) available on lenovo.com :/

 

[RehabMan]

Wow thanks for the quick answer. I'm already on the oldest BIOS (1.12) available on lenovo.com :/

There is a Linux technique for setting DVMT-prealloc. You might try that...

 

[unacson]

There is a Linux technique for setting DVMT-prealloc. You might try that...

Do you mean by checking the /sys/firmware/efi/efivars directory? Because if so, I'm not sure which var to modify, none of them mentions DVMT.

 

[RehabMan]

Do you mean by checking the /sys/firmware/efi/efivars directory? Because if so, I'm not sure which var to modify, none of them mentions DVMT.

Disclaimer: I've never been through this... don't have any Broadwell hardware.

Yes. Files are named by the module they are in. You've seen these names when you followed the UEFI guide. My understanding is you edit the file based on offset (it is a binary file).

Proceed at your own risk: If you do it wrong, you can brick your computer.

 

[unacson]

Hey, sorry it took me so long to answer. I booted on linux and checked the /sys/firmware/efi/efivars folder, but I'm not sure what I'm supposed to edit. Do you know if anyone has been successful with this method?

 

[RehabMan]

Hey, sorry it took me so long to answer. I booted on linux and checked the /sys/firmware/efi/efivars folder, but I'm not sure what I'm supposed to edit. Do you know if anyone has been successful with this method?

Some have reported success. You need to extract BIOS to analyse/find the variable offset/values.

 

[unacson]

I found the offset and the value (0x37 and 0x2, respectively), but I don't know which file to modify, or how to modify it. There are almost a hundred binary files. Do you know in what thread there has been success? I didn't see any mention of it on the main HD5500 thread.

 

[RehabMan]

I found the offset and the value (0x37 and 0x2, respectively), but I don't know which file to modify, or how to modify it. There are almost a hundred binary files. Do you know in what thread there has been success? I didn't see any mention of it on the main HD5500 thread.

The file is named after the GUID that contains the setting... It is something you discover when you analyse your BIOS extract.