Messages in this thread |  | | Date | Thu, 6 Jun 1996 02:31:02 -0400 (EDT) | From | Kenneth Albanowski <> | Subject | Re: SVGA kernel chipset drivers. |
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On Thu, 6 Jun 1996, Systemkennung Linux wrote:
> > > 2. Speed, lots calls to ioperm()/iopl() can't be good for > > > performance > > A single call to ioperm()/iopl() isn't good for portability.
Here's an idea: how about a _small_ kernel driver that mediates access to the range of I/O ports likely to be used by the video card? Only one device could open the driver at a time (that stops two processes from grabbing the screen at the same time) and simple read/writes could read and write to I/O ports in the specified range. (Maybe a write of 4 bytes means output second word to the I/O port named by the first word.)
_Everything_ else would go into user-space. All the kernel does is provide access to the I/O ports in question and keeps more then one program from using them at a time.
-- Kenneth Albanowski (kjahds@kjahds.com, CIS: 70705,126)
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