Arch Linux

deags

Member

Registered: 2012-12-28

Posts: 23

[Addressed] Compiled Kernel lacking features

Hi,
A while ago I was playing around with kernel compilation for a system that needed a custom kernel to enable deprecated features: namely UMS instead of KMS. I got a tarball from Linux's github release page (mainline), ran some make commands incl. menuconfig and got a working binary that I put into /boot. This build continues to work fine, but I had no idea what I was doing so I don't think i have headers etc where they are.

AUR has linux-mainline I later discovered. Edited the PKGBUILD to use menuconfig which I am familiar with, then had no issues until I tried to load the kernel.

First issue: no ext4 support. I had to change it to built-in to the kernel to be able to mount my root partition. Odd, hadn't had to do that before but it's working now.

But, UMS doesn't seem to load at all, ACPI complains about features missing (thinkpad_acpi was compiled into kernel, I checked). dmesg and grepping for phrases just shows nothing, neither of these things seems to work or attempt to load at all. If I try and startx, it fails to find screens because KMS isn't going.

I will try linux-git which I've succesfully done before, but it takes even longer than mainline because of the checkout time (Thinkpad T60 is getting old).

Any advice on getting the linux-mainline AUR compilation working as expected?

Thanks

Last edited by deags (2014-01-19 15:28:38)

Lone_Wolf

Forum Moderator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 11,966

Re: [Addressed] Compiled Kernel lacking features

The thinkpad T60 does use an ATI X1400 vga card i think ?

Then it's likely not a kernel issue, but a driver issue.

UMS support was removed from the opensource radeon driver xf86-video-ati some time ago.
This phoronix news item claims it was removed in xf86-video-ati-7.0.0 .
You may have to fallback to a pre-7.0.0 version to get X working with UMS.

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deags

Member

Registered: 2012-12-28

Posts: 23

Re: [Addressed] Compiled Kernel lacking features

Good job, you've made a liar out of me

I went and checked everything, it seems it's now running with KMS successfully. I've had to run with nomodeset on all distros for then to boot, but noticed one day that dmesg had a line saying UMS couldn't be started hence I started using it and things worked so I kept with it.

Unless this was a bug in the kernel that has been fixed recently, this is extremely strange. If it returns I'll repost with more details, but it seems for now I can join the KMS 99%

Thanks

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,804

Re: [Addressed] Compiled Kernel lacking features

In all seriousness, if you are building your own kernel, I would suggest you take a read through the documentation on the Gentoo website.  What they say about building a custom kernel is directly applicable to Arch.

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WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: [Addressed] Compiled Kernel lacking features

In all seriousness, if you are building your own kernel, I would suggest you take a read through the documentation on the Gentoo website.  What they say about building a custom kernel is directly applicable to Arch.

I think what they say about building a custom kernel is actually directly applicable to building a kernel for any distribution.  Though in Arch it is quite easy to package it up into a nice pkg.tar.xz