Nios UP vga

Hi all ,

Where can i read details about functions like :

alt_up_pixel_buffer_open_dev(); and alt_up_pixel_buffer_draw(); etc all that relate to vga SOC in UP .

I have read Altera ip Cores for DE boards , but it does not any details or examples of how to use these functions e.g

CHAR_BUFFER= alt_up_char_buffer_open_dev("/dev/video_character_buffer_with_dma_0");

where can i find /dev/video_character_buffer_with_dma_0 , i dont see any dev folder in my project ????

Regards ,