Well, I've figured out how to enable and/or run bootpd.  The "diskless" man
page talks about bootparams, but it looks like it's now /etc/bootptab.
I experimented, and it looks like bootpd never gets talked to; a standalone
bootpd -d9 says nothing.

The sun 4/110 now gets as far as
	Booting from tftp server at 192.129.84.17 = C0815411
	(swirly cursor, very fast, then slow)
	Requesting Ethernet address for 0..1.0.52 = 00010034

and times out forever.

I have a stripped "boot" from $SPARCROOT/usr/mdec/boot, made by dd
skip=1 bs=32 from the "standard" boot, as directed.  It's installed
as /tftpboot/C0815418.SUN4, and the client does seem to be finding
it.

I can't find "Requesting Ethernet" anywhere in the code for boot or
bootxx, so I don't know where it comes from.

-s