Re: s3 product

[Michael <macallan%netbsd.org@localhost>]

Hello,

On Nov 26, 2008, at 10:14 AM, rjs%fdy2.demon.co.uk@localhost wrote:

> What does PCI_MAGIC_IO_RANGE do ?

Tell display drivers and X at which offset to mmap the PCI IO range  
that belongs to the resp. framebuffer.

> Are accesses to it byte swapped for powerpc ?

Usually doesn't matter since few IO ports would be bigger than 1 byte  
but since the PCI bus is LE bigger accesses need to be swapped.

> When I last checked, the S3 driver in Xorg just does inw/outw calls  
> to the
> device registers.

Look at ppc_video.c and compiler.h, then you'll see that IO macros on  
powerpc translate to memory accesses relative to ioBase which is set  
by mmap()ing PCI_MAGIC_IO_RANGE.

have fun
Michael