Re: Moving away from /dev ?
On 19 Apr 1999, Thomas Bushnell, BSG wrote:
> OKUJI Yoshinori <okuji@kuicr.kyoto-u.ac.jp> writes:
> > > The attempt I once began foundered on the lack of adequate kernel
> > > facilities to do it, but that's fixable.
> > I want to know what facilities are lack precisely. If you give me
> > the clue, I may fix that.
> Basically, we need a call that will return all the valid device names
> that the kernel understands (the list should reflect what is actually
> present on the machine, and not be a list just of particular pieces of
> hardware that might be there).
>
> It also needs to be possible to tell, for each device, exactly what
> kind of device it is, in some manner that does not cause the device to
> do anything at all. (Doing device_open/device_get_status/device_close
> would be OK, except that some devices block on open, and many do
> things on close, and there is no guarantee that every device will
> support an appropriate device_get_status type query.)
Would having such a device structure (kernel level devices exporting
symbols) be all that much of an architecture win? I still feel
that having the kernel only export hardware access (providing a
namespace where a device can attach to a file in that namespace
and gain hardware access, all controlled via standard hurd authentication)
would be a big win.
The ability for drivers to be userland, indeed, for a driver to run on
a machine other than the one the hardware device is on, provides
significant benefits.
Reply to: