port-pmax: 1.3F kernel panics on boot from disk, not tftp?

Subject: 1.3F kernel panics on boot from disk, not tftp?
To: None <port-pmax@NetBSD.ORG>
From: Jonathan Stone <jonathan@DSG.Stanford.EDU>
List: port-pmax
Date: 06/16/1998 01:47:38

I get the following consistently on a 5000/150 when I try and boot an
R4000 kernel (yesterday's -current)

(starting at 0x80003000)

panic: kernel stack overflow
ktlbmiss: PC 8003a9f8 RA 80145d60 ADR 11c
SR 20000002 CR 3000040c SP 8002ffa0
TLB* 0 vad 0x80000000 0=0x00000000    atr 0 1=0x00000000    atr 0  sz=0
TLB* 1 vad 0x80000000 0=0x00000000    atr 0 1=0x00000000    atr 0  sz=0
TLB* 2 vad 0x80000000 0=0x00000000    atr 0 1=0x00000000    atr 0  sz=0
panic: kernel stack overflow

(repeated ad nauseam)

But if I instead tftpboot the netbsd.ecoff kernel built at the same
time, it boots to a sh prompt.  Anyone else seen this?