more dynamic autoconf (was Re: libusb-1.0 for NetBSD)

[David Young <dyoung%pobox.com@localhost>]

On Wed, May 30, 2012 at 12:26:27PM -0500, Eric Haszlakiewicz wrote:
> On Wed, May 30, 2012 at 04:45:13PM +0100, Stephen Borrill wrote:
> > On Wed, 30 May 2012, Xiaofan Chen wrote:
> > >libusb-1.0 under OpenBSD/NetBSD use ugen, so only
> > >ugen device are supported.
> >
> > One of the problems with libusb with NetBSD is that it cannot detach a 
> > driver and reattach ugen. So if uhid has attached, you are stuck with it.
> 
> I just ran into this problem myself.  I was thinking of adjusting the usb
> code so all devices can support the same ioctl's that ugen supports, but
> things got a bit trickier than I expected.
> One of the problems is that not all usb devices have a device node in /dev,
> and there's no way to walk the device tree by (e.g.) operating on a hub
> device (/dev/usb0) so there doesn't seem to be a way to indicate that you 
> want to do something with a particular usb device. :(

Sometimes I have wished for a way to modify the kernel's
autoconfiguration data---by which I mean the code & structs derived from
the kernel's config(5) file---from userland in order to stop one driver
from ever (re-)attaching to a device or to make a new/different driver
attach.  It seems to me that this would be a generally useful facility
to have.

It would be nice if we had a richer set of locators, too: strings, byte
tuples, ....

It seems like one or more person has started the project of revamping
autoconf(9) but abandoned it for one reason or another.  I'd sure like
to see someone finish.  I think that it would un-block one or two of my
personal projects and help others' projects to get started, too.

Dave

-- 
David Young
dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981