HOWTO get the HP9000/340 to boot:

1) rbootd - you need the sources from http://mnementh.trin.cam.ac.uk/hp/
The current version no longer includes a copy of libpcap.a; there is
a Debian package (libpcap0 and libpcap-dev are what you want), or you
can use the Debian upstream sources as a convenient way to get a tar.gz.

rbootd should compile cleanly on a libc6 system; I don't know if it will
work on a libc5 box -- reports of successful compiles welcome...

2) bootparamd - my sources wouldn't compile unless all the rpcgen
stuff was done on a handy Sun... I'm told there's a RedHat binary .rpm
package for bootparamd (in the contrib directory?), which may be more 
reliable. I've made the version I used, together with the bits I had to
use a Sun for, available anyway...

NEW - Neal Blount (thecat@ee.techpta.ac.za) has the following suggestions
for compiling bootparamd - thanks!

>How to compile the rpc.bootparamd on Linux.
>get the following archives:-
>Linux-Xkernel-2.0a.tar.gz (1231579)
>rpc-1.00.tar.gz (208878) 0.9 may work aswell.
>
>* compile the rpcgen program in rpc-1.00.tar.gz (ignore warning)
>* copy the rpcgen program to the bootparam directory
>Linux-Xkernel-2.0a.tar.gz
>  tree
>* modify the make file to use the new rpcgen
>* make
>
>compile with errors :-( but at least it now compiles.

Note that the bootparams bits of Linux-Xkernel-2.0a.tar.gz
should be in bootparams.tar.gz on this site. 

NEW 02/1998: SALEM@statoil.no pointed out that bootparamd is in newer
versions of the Debian netstd package.

3) Config files:
cat /etc/rbootd.conf
# 
# Config for rbootd - boots HP workstations over ethernet
# 
# ethernet address       bootfile        
08:00:09:03:24:01       SYS_NBOOT       # tiroth
bash# cat /etc/bootparams 
tiroth root=dram:/export/hp/root/ \
       swap=dram:/export/hp/swap

# note : I have the lines in /etc/hosts:
#192.168.1.1             mnementh dram
#192.168.1.2             tiroth

cat /etc/exports
# /etc/exports: the access control list for filesystems which may be exported
#               to NFS clients.  See exports(5).
# allow the HP to access its root filesystem :-)
/export/hp/root tiroth(rw,no_root_squash)
/export/hp/swap tiroth(rw,no_root_squash)

4) Server programs to run:
rbootd -i eth1
rpc.rbootparamd
nfsd and mountd
rarp -s tiroth 08:00:09:03:24:01  # set up RARP table
arp -s tiroth 08:00:09:03:24:01   # ditto for ARP table
# the arp entry isn't required, but it prevents timeouts at the bootparams 
# stage - the Linux box won't respond until the HP has replied to an 
# arp request...

5) Directory structure: I used
/export/hp/root  - untar the base12 and etc12 tarfiles into here
                   also the netbsd generic kernel file.
                   You then need to run MAKEDEV std in the dev subdir.
/export/hp/swap - create it at whatever size swap you want. just touching it
will work with zero swap...
/export/hp/rbootd - this is where I keep SYS_NBOOT [this directory
must be specified to rbootd at compile time!)

6) The Swedish problem: set your terminal to ignore the 8th bit of all
characters. In general terminal settings should be 9600 baud, 
8 data bits, 1 stop bit, no parity, ignore 8th bit.

7) If your HP sticks halfway through boot trying to write to the NFS system:
this is a symptom of using Linux as an NFS server. Linux NFS can't cope
with 8K write requests, which are fragmented across several packets. The
solution is to remount the root filesystem to use 1K blocks, by putting
the following line near the top of the HP's /etc/rc :

# Very first thing to do is remount root with sensible values
# for using Linux as an NFS server:
mount -t nfs -a -o -I=1024,-r=1024,-w=1024 dram:/export/hp/root/ /

Note that this isn't a real solution, since swap is still using 4K writes.
(ie as soon as it starts to swap, it'll fall over!) 
Suggested fix is to build a kernel with:
options NFS_BOOT_RWSIZE=1024

8) You might perhaps have trouble with root logins via the serial 
console (I don't know why I can't do this...) I just edited 
/export/hp/root/etc/ttys to make network connections secure.

9) Probably lots of other stuff I missed... You'll probably find it
convenient to continually run tcpdump while testing all this...
Anybody asking me to debug "it won't boot" problems should include
the tcpdump output, please :-)

10) A workaround for failing to boot is to arrange things so the HP 
and the server are the only machines on the network cable.
High network traffic seems to have caused problems for some people.

Peter Maydell