Now needs to be on my side arm of the inside of the SOC GPU (mali400) to use up, my side has the GPU driver module Mali. Ko compiled, also find the corresponding user space libmali. So libraries, normal compiled test program, but call eglGetDisplay function always returns EGL_NO_DISPLAY, main don't know how to put the GPU and display devices, do not know if call eglGetDisplay needs corresponding device node, or need other things, has more clearly on the arm chip using GPU experience to help give directions, thank you!!!!!