Odroid Mali-400 proprietary support libraries. Hardkernel/Odroid tends to package them as part of bigger packages, which is inconvenient when building an linux image from scratch.
On Debian Jessie, these files should be copied to /usr/lib/arm-linux-gnueabihf. On most other systems, it should be /usr/lib.
The R3P2 binaries were downloaded from http://dn.odroid.com/MALI400_R3P2/20130429-for-xorg-1.13.3/mali_packages.tar.gz
These packages include a binary for the xf86-video-mali driver. When using a different version of X11, it needs to be rebuild. The sources can be found at: http://malideveloper.arm.com/downloads/drivers/DX910/r3p2-01rel4/DX910-SW-99003-r3p2-01rel4.tgz
The xf86-video-mali driver is known to copy the pixel data around quite inefficiently using ump for shared memory.
These are hopefully part of http://www.odroid.in/lubuntu-13.10-xbmc/lubuntu-desktop-13.10-armhf-odroidx2_20140408.img.xz
They can be used with the armsoc X11 driver, which uses DMA-buf for shared memory and should have higher performance.
Copied from http://builder.mdrjr.net/tools/u3/4412_r5p0_x11.tar.xz These don't require libUMP anymore. A matching kernel for the X2 can be found at https://github.com/hardkernel/linux/tree/1130f8761789bfe79de0db2b7f5013ff3eb1f978