I am trying to understand how the frame-buffer driver works.(I have some exposure to how char. drivers are written thru' LDD3 and trying to understand a real-world driver). I am looking at drivers/video/vfb.c as a model before looking at the driver for a h/w chip.
1) To start with I am a little confused about the device itself. According to my understanding a frame buffer is a graphical chip which contains the neccessary information about a particular frame to be displayed. But what is the role of virtual frame buffer ?
2) How are the operations defined in "vfb.c" requested. Because there dosent seem to be any ioctl's which can be requested to invoke these operations? So basically what is the entry point into the driver ?
Any pointers is highly appreciated.Thanks grp.
rgds
Arun
