Xorg Segmentation fault at 0x0

[srinivasaporam]

Hi,

We have got I.MX6 Q /DL reference boards for which we are trying to port ubuntu. When we are trying with kernel 3.10.53 , we are not facing any problem (board is booting successfully with lxde desktop), But when we are trying with 3.14 kernel, xorg is failing and when we run startx command it is giving following error:

Segmentation fault at address 0x0

Fatal server error:

caught signal 11 (segmentation fault ). server aborting. What could be the problem????

Please find the config files for both the kernels.

Original Attachment has been moved to: config-3.14.14+.zip

Original Attachment has been moved to: config-3.10.53-1.1.0_ga-wandboard-06112-g166aa6f.zip

[srinivasaporam]

Hi,

I checked same 3.14 kernel with ubuntu12.04 armhf (precise) rootfs. It is working fine and i could able to get the lxde desktop. It is only problem with 14.04 rootfs.

I think the version of Xorg (2:1.15) is the one which is creating problem. any inputs on this will be helpful????

[gary_bisson]

Hi,

Maybe your 12.04 rootfs isn't configured with Vivante whereas the 14.04 is.

Anyway, 14.04 is working just fine with the 3.14.28 kernel when the graphics libraries are matching. Here is a blog post about our release which works on all our platforms with the 3.14 kernel:

https://boundarydevices.com/ubuntu-trusty-for-i-mx6-boards-february-2016-kernel-3-14-28/

Regards,

Gary

[Bio_TICFSL]

Hi,

Correct! in this case for 3.14.28 you should use GPU driver  v5.0.11p4.4. For 3.10.53 v5.0.11p4.1, Xorg 1.15.0v can be used in both kernel versions.

Regards

[srinivasaporam]

Hi,

I have two sd cards in which one sd card, i have ported ubuntu rootfs with 3.10.53 kernel and another one with 3.14 kernel with same rootfs. when i put first sd card, then i could able to get lxde gui but fails to load lxde or start x with the other one. can you tell me what could be the problem????

I just want frame buffer only... frame buffer should work with both the kernels right????

[gary_bisson]

Hi,

The problem is the one I said above: the graphics libraries version do not match the kernel driver since you keep the same rootfs with 2 different kernels.

I'm pretty sure your xorg.conf is configured to use vivante which is the 3D/2D GPU for rendering, so it fails.

Also, yes the frame buffer works with both, try that:

$ cat /dev/urandom > /dev/fb0

If it displays something it proves the framebuffer works, but doesn't mean your X setup will.

You can try modifying xorg.conf not to use the GPU but I'm not sure of the result.

Regards,

Gary

[gary_bisson]

Hi,

You can't switch kernels from 3.10 to 3.14 without updating the graphics libraries for the GPU. Every kernel revision provided by NXP (3.10.53, 3.14.28, 3.14.52...) matches one specific version of the graphics libraries. So you need to update the libraries to match the exact kernel you are using. Otherwise when X starts, it fails to load the graphics since the driver returns a version which is unknown to them.

Regards,

Gary