Video cards always have a certain amount of RAM. This RAM is where the bitmap of image data is buffered for display. From the software point of view, the framebuffer is a character device providing access to this RAM.
That said, a framebuffer driver provides an interface for:
- Display mode setting
- Memory access to the video buffer
- Basic 2D acceleration operations (for example, scrolling)
To provide this interface, the framebuffer driver generally talks to the hardware directly. There are well-known framebuffer drivers, such as:
- intelfb: A framebuffer for various Intel 8xx/9xx compatible graphic devices
- vesafb: A framebuffer driver that uses the VESA standard interface to talk to the video hardware
- mxcfb: A framebuffer driver for the i.MX6 chip series
Framebuffer drivers are the simplest form of graphics drivers under Linux. They should not be confused with...