eglGetDisplay Return EGL_NO_DISPLAY

Hi expert,

I use a SOC with Mali-G78AE,I run a linux without desktop system.

When I use gbm_create_device to get gbm_device,I can get an non-null pointer. Then ,I use it to call eglGetDisplay,but I can get a EGL_NO_DISPLAY.

What is reason for error result ?Can you give me some suggestion?

The following is some log:

g_device_fd = 3
connector_id = 107,encoder_id = 106
resolution: 1920x720
gbm_device = 0x1cbab330
eglGetDisplay failed