Created attachment 1384 [details] Xorg.0.log logging when the crash happens X crashes every time since the new i.MX6Q BSP 3.5.7-1.0.0 has been introduced when building a softfloat image. X starts fine if the build is hardfloat. Poky from master + meta-fsl-* from master-next as of 26/07/2013.
See also the discussion in i.MX Community: https://community.freescale.com/thread/310233
This has been fixed some time ago with the drm and GPU 4.6.9p12 backport for 3.0.35-4.0.0 kernel.