Re: NetBSD/sgimips 10.0 RELEASE on SGI Challenge S: INSTALL32_IP2x works, GENERIC32_IP2x kernel panics on boot after install

Hello,

On Mon, 20 May 2024 10:12:55 -0700
Tim McIntosh <[email protected]> wrote:

> I've bricked my SGI Challenge S server after deciding to upgrade it
> to 10.0 yesterday (was running NetBSD 5.0 (GENERIC32_IP2x) #0: Mon
> Apr 27 06:08:08 UTC 2009).

I'll dust off my R5k Indy, it's been a while though.

> I got through the installation just fine (after workaround around a
> problem with lack of `chflags` in the installation image), but after
> rebooting, the system now panics every time; I’ve filed this problem
> report:
> 
> 	https://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=58269

I don't have a CDROM drive on my Indy, I always installed everything by
netbooting it.

> What I filed in the problem report is actually using the ecoff kernel
> variant. For some reason, the ELF variant panics much earlier, though
> prior to this upgrade I was using the ELF variant with NetBSD 5.0:

Hmm, I'm pretty sure the last time I messed with the Indy was at least
9.x -current.

> > NetBSD/sgimips 10.0 Bootstrap, Revision 1.5 (Thu Mar 28 08:33:33
> > UTC 2024) 
> > devopen: scsi(0)disk(3)rdisk(0)partition(0) type scsi file
> > netbsd-GENERIC32_IP2x 5004432+126464 [270656+264073]=0x567868
> > Starting at 0x88069000
> > 
> > nsym 0x1 ssym 0x88544a90 esym 0x885c7868
> > 
> > Exception: <vector=UTLB Miss>
> > Status register: 0x2<IPL=8,MODE=KERNEL,EXL>
> > Cause register: 0x30008008<CE=3,IP8,EXC=RMISS>
> > Exception PC: 0x0, Exception RA: 0x882e3c0c
> > exception, bad address: 0x0
> > Saved user regs in hex (&gpda 0xa8740e48, &_regs 0xa8741048):
> > arg: a8740000 5f 0 2
> > tmp: a8740000 88510000 2764 41ff 885870dc 885870dc 8848c01c
> > 8853b200 sve: a8740000 0 0 0 0 0 0 0
> > t8 a8740000 t9 0 at 0 v0 0 v1 0 k1 88520000
> > gp a8740000 fp 0 sp 0 ra 0
> > 
> > PANIC: Unexpected exception
> > 
> > [Press reset or ENTER to restart.]

If I read this correctly something jumped to NULL in early kernel
startup. Shouldn't be too difficult to find.

> When filing the problem report, I was reminded that I had run into
> some potentially-related problem when attempting to upgrade to 5.1.2
> (which I never succeeded in doing) back in 2012:
> 
> 	https://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=46417
> 
> Since the installation image works, but booting the installed kernel
> fails, I’m guessing there’s something wrong with the GENERIC32_IP2x
> config?

These kernels should differ only in the amount of drivers /
non-essential kernel subsystems built into them, the crash happens
*way* early, before any of those should make a difference. I wonder if
the kernel image got too fat and we hit some hidden firmware limit...

> Does someone have the ability to build and post a standalone kernel
> equivalent to the INSTALL32_IP2x config? I’m hoping that would allow
> me to boot the system.

As said above, I'll dust off my R5k Indy, last time I checked it worked
just fine. That was a few years ago though, and it will take me a while.
What I would do in your position is:
- setup netboot - IIRC it's really just bootp/dhcp, load kernel via tftp, mount root via nfs.
- build an INSTALL32_IP2x kernel, try to netboot it
- INSTALL* is just GENERIC* with a bunch of 'no *' statements to strip
  it down. Enable a few of them, try again. If my theory is correct it
  should start crashing when the kernel image hits a certain size
- you probably don't want all the stuff disabled in INSTALL32_IP2x, if
  you get to an image that's small enough to work and contains what you
  need, I'd run with that for the time being.

have fun
Michael