Thanks for your suggestion.
Actually I am using L3.0.35_4.0.0_130424 release with ubuntu_oneiric_4.0.0.tgz rootfs.
I found the 2D performance is not so good. The Xorg's CPU usage will be very high when moving the window or playing a GIF file.
So I want to re-compile the Xorg and xserver-xorg-video-imx-viv-3.0.35-4.0.0 driver with debug message, then use some tools, such assysprof, to find which function of Xorg or driver cost more CPU usage. Then modify it if possible.
By the way, does FreeScale have a BSP release to improve the 2D performance on Ubuntu?
Thanks!