Re: SVGA kernel chipset drivers.

Alan Cox (alan@lxorguk.ukuu.org.uk)
Sat, 1 Jun 1996 00:34:09 -2300 (BST)

> Nope, the kernel can provide a framebuffer device in /dev that
> programs can mmap. IO port access is less critical.
We had this argument before. Some cards dont have a frame buffer.

I/O port access is critical. The "frame buffer" of most cards is actually
a window of 64K onto a mapped space. Its critical enough the X servers do
iopl() rather than ioperm to save a few clocks (2 or 3) for each out/in they
do.

> The real reasons for such a driver are reliability and security.

Which only need kernel support for "restore to text mode".