I recently installed NetBSD on my Challenge S. I left it on overnight and
when I came back in the morning, this was what I found. IIRC, I was
installing some stuff from pkgsrc when I last left the machine. I stupidly
typed "next" before I did "ps" in the debugger. However, here is the info
I did get before rebooting the box.

db> trace
cpu_Debugger+4 (8ffff000,64,0,0) ra 88165070 sz 0
panic+124 (882cb794,64,0,0) ra 88279a24 sz 40
pmap_zero_page+20 (882cb794,64,0,0) ra 8826f6c0 sz 32
uvm_pagealloc_strat+5a4 (882cb794,64,0,0) ra 88279560 sz 64
pmap_enter+398 (882cb794,64,0,0) ra 88263744 sz 80
uvm_fault+c0c (88e35bb8,7fffe000,0,1) ra 8827b60c sz 296
trap+4d0 (4ff13,7fffe000,0,1) ra 88275084 sz 64
mips3_UserGenException+cc (4ff13,7fffe000,0,410308) ra 0 sz 0
User-level: pid 6874

db> machine cp0
  index:      0x15
  random:     0x10
  entrylo0:   0x219a1f
  entrylo1:   0x236a5f
  context:    0x3f44828181600050
  pagemask:   0
  wired:      0x1
  badvaddr:   0xffffffffc000a960
  count:      0x714eed8f
  entryhi:    0xc00000ffc000a04c
  compare:    0x307f88e2
  status:     0
  cause:      0x8624
  epc:        0xffffffff88276a20
  prid:       0x460
  config:     0x20c1c483
  lladdr:     0xff56df49
  watchlo:    0
  watchhi:    0
  xcontext:   0x3f448281ffe00050
  ecc:        0
  cacherr:    0xe43e6796
  cachelo:    0
  cachehi:    0
  errorpc:    0xffffffff88164f4c

> hinv -t
system ARC SGI-IP22 key 0
  processor CPU MIPS-R4400 key 0
    processor FPU MIPS-R4400FPC key 0
    cache primary icache 16 Kbytes (block 1 lines, line 16 bytes)
    cache primary dcache 16 Kbytes (block 1 lines, line 16 bytes)
    cache secondary cache 1024 Kbytes (block 1 lines, line 128 bytes)
    memory main 128 Mbytes
  controller network ec0 key 0
    peripheral network key 0
  adapter SCSI WD33C93B key 0
    controller disk IBM DDRS-39130 key 1
      peripheral disk unit 0
    controller disk INSITE I325VM        *F key 2
      peripheral floppy disk key 0
  controller serial IP22 tty key 0
    peripheral line key 0
  controller serial IP22 tty key 1
    peripheral line key 0
  controller keyboard pckbd key 0
  controller pointer pcms key 0