Re: __BROKEN_CONFIG_UNIT_USAGE ?

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

On Tue, Dec 01, 2009 at 05:52:44PM -0600, David Young wrote:
> On Tue, Dec 01, 2009 at 01:48:44PM -0800, Jason Thorpe wrote:
> > 
> > On Dec 1, 2009, at 12:46 PM, David Young wrote:
> > 
> > > On Tue, Dec 01, 2009 at 09:44:29PM +0100, Manuel Bouyer wrote:
> > >> On Mon, Nov 30, 2009 at 01:54:13PM -0600, David Young wrote:
> > >>> Only NetBSD/sun3 uses __BROKEN_CONFIG_UNIT_USAGE.  The name of this
> > >>> mysterious #define, which affects which code in subr_autoconf.c is
> > >>> compiled, implies that sun3 is somehow "broken"?  Will somebody fix it?
> > >> 
> > >> So you know what is broken exactly ?
> > > 
> > > No, I do not.  I'm hoping that some NetBSD/sun3 developer knows.
> > 
> > The code makes assumptions about the behavior / relationships of
> > devices at fixed unit numbers.  See sun3/sun3/vme.c:vme_match(),
> 
> Can this magic in vme_match()
> 
> #define VME_UNITS       6
> 
>         unit = cf->cf_unit;
>         if (unit >= VME_UNITS)
>                 return 0;
> 
>         if (ca->ca_bustype != vme_info[unit].bustype)
>                 return 0;
> 
> be avoided by creating a new locator, "bustype", and
> rewriting the kernel configuration
> 
>         vme0 at mainbus? # A16/D16
>         vme1 at mainbus? # A16/D32
>         vme2 at mainbus? # A24/D16
>         vme3 at mainbus? # A24/D32
>         vme4 at mainbus? # A32/D16
>         vme5 at mainbus? # A32/D32
> 
> as follows?
> 
>         vme0 at mainbus? bustype 0 # A16/D16
>         vme1 at mainbus? bustype 1 # A16/D32
>         vme2 at mainbus? bustype 2 # A24/D16
>         vme3 at mainbus? bustype 3 # A24/D32
>         vme4 at mainbus? bustype 4 # A32/D16
>         vme5 at mainbus? bustype 5 # A32/D32
> 
> > and to a lesser extent, sun3/dev/xd.c:xdmatch() and
> > sun3/dev/xy.c:xymatch().
> 
> Wow, what are *those* doing?  Any reason that cannot be expressed in the
> kernel configuration, too?

It looks to me like the relationships can be expressed in the
kernel configuration file.  I am going to delete all of the #ifdef
__BROKEN_CONFIG_UNIT_USAGE code from sys/kern/subr_autoconf.c in a week.
I will send an untested patch to try to ease sun3's transition.

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933