Re: FW: XFree86 Port (Message from XFree86/OS2 developer)

[Mumit Khan <khan@xraylith.wisc.EDU>]

"Suhaib M. Siddiqi" <ssiddiqi@inspirepharm.com> writes:
> 
> Ernie, no, it is not supported by cygwin, that is /dev/iopl, unless
> I am missing something.  That is what Holger meant when he talked about
> mmap/munmap.  Mmap and munmap is in Cygwin, but dunno how it relates to
> /dev/iopl.  I had been studying the codes which handle /dev/iopl on Unices.
> Below is a sample from GNU MACH.  The /dev/iopl is hard coded at 1000s times
> to access all kinf memories (video blah blah). Holger suggested, writing a
> small
> device driver which read the physical memory and using his OS/2 code in
> XFree86.

/dev/iopl is a *very* Linux specific thing, and it essentially allows you 
to map io ports to memory regions (or something like that). Needs to be
followed by call to iopl(<level>), another linux specific routine, to 
change the I/O privilege level that allows the access the FIFO ports.

As far as I know, it's only needed for 8514 servers, but I haven't looked
at this stuff for years, so quite out of date.

I believe you'll need to look at win32 api to start adding these in since
Cygwin doesn't wrap it.

Unfortunately, my knowledge of win32 api is very limited, and can't be of 
much help here.

Regards,
Mumit