Just been giving Alistair G. Crooks update process (for i386) a go on
a Sparc 2. 

Got as far as:

(cd /usr/src/usr.sbin/config.new ; make && make install && make cleandir)
(cd /usr/src/gnu/usr.bin/gas ; make && make install && make cleandir)
cd /sys/arch/sparc/conf
cp GENERIC_SCSI3 HOBBIT

vi HOBBIT	# just upped maxusers and ptys for now...

config.new HOBBIT
cd ../compile/HOBBIT

make depend && make

# had to make the following change to net/if.c

*** net/if.c.~1~    Thu Mar  9 22:38:48 1995
--- net/if.c        Fri Mar 17 15:44:52 1995
***************
*** 574,580 ****
  /*ARGSUSED*/
  int
  ifconf(cmd, data)
!       int cmd;
        caddr_t data;
  {
        register struct ifconf *ifc = (struct ifconf *)data;
--- 574,580 ----
  /*ARGSUSED*/
  int
  ifconf(cmd, data)
!       u_long cmd;
        caddr_t data;
  {
        register struct ifconf *ifc = (struct ifconf *)data;

installed the kernel and booted....

Boot device: /sbus/esp@0,800000/sd@3,0   File and args: netbsd
root on /sbus/esp@0,800000/sd@3,0 fstype 4.2
Boot: netbsd
Size: 827360+82368+87920 bytes
Copyright (c) 1982, 1986, 1989, 1991, 1993
        The Regents of the University of California.  All rights reserved.

NetBSD 1.0A (HOBBIT) #0: Fri Mar 17 16:06:39 EST 1995
    root@hobbit:/usr/bsd_src/src/sys/arch/sparc/compile/HOBBIT
real mem = 16449536
avail mem = 14184448
using 200 buffers containing 819200 bytes of memory
mainbus0 (root)
cpu0 at mainbus0: SUNW,Sun 4/75 (RT601 or L64811 v2 @ 40 MHz, TMS390C602A FPU)
cpu0: cache chip bug; trap page uncached
cpu0: 65536 byte write-through, 32 bytes/line, hw flush cache enabled
memreg0 at mainbus0 ioaddr 0xf4000000
clock0 at mainbus0 ioaddr 0xf2000000: mk48t02 (eeprom)
timer0 at mainbus0 ioaddr 0xf3000000
auxreg0 at mainbus0 ioaddr 0xf7400003
zs0 at mainbus0 ioaddr 0xf1000000 pri 12, softpri 6
zs0a: console i/o
zs1 at mainbus0 ioaddr 0xf0000000 pri 12, softpri 6
audio0 at mainbus0 ioaddr 0xf7201000 pri 13, softpri 4
sbus0 at mainbus0 ioaddr 0xf8000000: clock = 20 MHz
dma0 at sbus0 slot 0 offset 0x400000: rev 1+
esp0 at sbus0 slot 0 offset 0x800000 pri 3: ESP100 20Mhz, target 7
scsibus0 at esp0
esp0 targ 3 lun 0: <SEAGATE, ST1480   SUN0424, 5826> SCSI2 0/direct fixed
sd0 at scsibus0: 411MB, 1476 cyl, 9 head, 63 sec, 512 bytes/sec
esp0 targ 4 lun 0: <ARCHIVE, VIPER 150  21531, -004> SCSI1 1/sequential removable
st0 at scsibus0: drive empty
le0 at sbus0 slot 0 offset 0xc00000 pri 5: hardware address 08:00:20:10:1d:55
bf at sbus0 slot 2 offset 0x0 not configured
cgsix0 at sbus0 slot 3 offset 0x0: SUNW,501-1672, 1152 x 900, rev 6
fdc0 at mainbus0 ioaddr 0xf7200000 Hmmm..  pri 11, softpri 4: chip 82077
root on sd0a
~

That's where it stopped... It did this with the Jan08 kernel when I
tried configuring in the fd driver, so I'm commenting that out and
trying again...