On Sun, 4 Feb 96 13:48:57 PST 
 "Scott L. Burson" <gyro@zeta-soft.com> wrote:

 > Well, that's why there should be (and is) a separate sun4c kernel.

BZZT.  Look at GENERIC ... it boots on the sun4 and sun4c.  A lot of 
effort was put forth into making a "unified" 4/4c kernel, and that will 
continue once the 4m support is integrated.

 >    sun4:
 >    	sd0	id0 lun0
 >    	sd1	id0 lun1
 >    	sd2	id1 lun0
 >    	sd3	id1 lun1
 > 
 > Say what?  I used to have a 4/110, and it didn't do anything like this...

#
# Support for the "SCSI weird" host adapter used with the Sun-4/110.
#
controller      sw0 at obio 2 csr 0xa000000 priority 2
tape            st0 at sw0 drive 040 flags 1
tape            st1 at sw0 drive 050 flags 1
disk            sr0 at sw0 drive 060 flags 2
disk            sd0 at sw0 drive 000 flags 0
disk            sd1 at sw0 drive 001 flags 0
disk            sd2 at sw0 drive 010 flags 0
disk            sd3 at sw0 drive 011 flags 0
disk            sd4 at sw0 drive 020 flags 0
disk            sd6 at sw0 drive 030 flags 0

This is right out of the stock SunOS 4.1.3 GENERIC configuration.

 >    It gets even weirder ... some hp400 BOOTROMs expect:
 > 
 > Well, then there should be HP kernels distributed with that mapping too.

Umm .. except that you can't tell the difference between PROMs that 
expect this and ones that don't.  Also, you can turn that reverse mapping 
off on some of them.  And, it only applies when the PROM is searching for 
a bootloader...

 > It's not a whole lot of work to produce these kernels, is it?  And they don't
 > take up a lot of space on the FTP server (or they wouldn't if compressed).  So
 > what's the problem?

For a volunteer port-master (i.e. all of us who are port-masters), it can 
be a real headache to keep all of the kernel configs in sync.  For those 
of us who have to ship kernels to the FTP server via slow 14.4k links, 
it's a pain.  If your build machine is slow, it's a pain.

On the other hand, having one GENERIC kernel that's going to find all of 
your SCSI disks no matter where they're located is really nice.

 > Well, to each their own.  Personally, my feeling is that I'm not interested in
 > using the dynamic mapping feature anyway, so that if I had a machine with
 > multiple controllers (which I don't, and quite possibly never will) I would
 > have to config a kernel for that machine anyway.

And, in that case, you can configure your kernel with static SCSI mappings.

 > Okay, how about this.  You're already distributing one fully dynamic kernel
 > and one that swaps 3 and 0 but leaves 1 and 2 dynamic.  How about just
 > changing the latter to map 1 and 2 statically, and adding one that does a
 > straight-through static mapping?

I'll let the SPARC port-master make that decision.  It's not mine to make :-)

 >    I'm talking about having to reompile the kernel when you want to add a second
 >    swap drive, or the (supposed) inability of the normal kernel to mount anything
 >    else than /dev/sd0a on /. The root drive should be the same as the boot drive
 >    rather than being hardcoded in the kernel.
 > 
 > Truly!  This would also be a big help to first-time installers (not only is
 > it the way SunOS works, it's just plain more convenient to be able to install
 > the distributed kernel on any drive).  [This hasn't been done yet?  I haven't
 > gotten around to installing 1.1 -- indeed I haven't used NetBSD since about
 > last May, when I concluded that 1.0 wasn't quite soup yet.]

Now you have me confused.  The GENERIC SPARC kernel can boot/mountroot 
from any drive + network.  Same with the hp300 GENERIC.  Same with the 
sun3 GENERIC (I know - I have a sparc, sun3, and a bunch of hp300s at 
home).  Other ports may differ for various reasons (like, gee, 
it's really hard to figure out which drive you booted from because the 
PROM doesn't tell you, etc.).

--------------------------------------------------------------------------
Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939