Re: replace a legacy proprietary RTOS (Real-Time executive) with NetBSD!

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Mon Jan 12 2009 at 18:36:55 +0100, Thirupathiah Annapureddy wrote:
> Hi,
> 
> Thanks again for your quick reply.
> 
> Regarding fielding the interrupts in user space, my question was
> whether it is possible to write user mode device drivers. In the case
> of user-mode drivers, the interrupts need to be handled at the user
> space level. Also device address space need to be mapped into the user
> space to control/configure the device.

What kind of drivers do you have in mind?  I have been thinking
about making it possible to run the same device driver code in user-
or kernelspace for quite a while now, but I haven't had any motivation
apart from "would be nice" so far.  Your goal seems to be a special case
of my goal.

We already support file systems and the tcp/ip stack in userspace, so
device drivers would not be very far off, although of course they have
their own specific subproblems.