Re: userspace drivers

[Robert Millan]

On Wed, Feb 05, 2003 at 03:06:17PM -0800, Thomas Bushnell, BSG wrote:
> Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de> writes:
> 
> > The question of user interrupt handlers: There is an interface, but I don't
> > think it was ever tried in GNU Mach, so I don't know if that works or can be
> > resurrected.  In any case user space drivers are only interesting in a more
> > modern microkernel like L4.
> 
> I would suggest not spending time right now on user-space drivers.
> They are interesting in Mach, but it's the kind of thing that we might
> well end up throwing away upon a switch to another kernel.

well, from my tiny experience on writing a parallel port driver i can say
that userspace drivers for GNU are very portable. The only system resources
one needs (besides Hurd's fs libraries of course) is a working ioperm(), which
is a portable function, and a way to wait for interrupts, ala
intwait(unsigned short), which should be portable too.

is such work welcome then? i mean, if i write a decent driver will it be
included in the Hurd now or in a later term?

if there isn't interest at the moment i might consider creating a subproject
at savannah for userspace drivers, but only with the certainty that they will
go official sooner or later.

-- 
Robert Millan

"Omnis enim res, quad dando non deficit, dum habetur et non datur,
nondum habetur, quomodo habenda est."

"For if a thing is not diminished by being shared with others, it is
not rightly owned if it is only owned and not shared." 

                Aurelius Augustinus (354-430)