You can netboot Ultrix from Linux

[dreamlayers]

I got the NetBSD mopd (DEC network boot server daemon) fully working in Linux and added a few things to make it capable of the 3 stage Ultrix mop boot. There are some NFS server incompatibilities, and I describe binary patches for those.

https://github.com/dreamlayers/netbsd-mopd

In particular for Ultrix related info see: https://github.com/dreamlayers/netbs...mlayers/ultrix

I have successfully netbooted Ultrix 4.5 on VS2000, VS3100 m38, KA630 and KA650, and also booted Ultrix 4.0 on some of those. I recommend using the old style graphical environment on those systems. Motif looks better but is too slow. Even a VS2000 with only 4 MB RAM can run the old graphical environment when booted with a stripped down smaller kernel.

BTW I have not done any work on netbooting VMS. If you want that, set up a VAX in simh and netboot using that as the server.

[ajacocks]

That is so cool! I can’t wait to try this out.

Have you attempted to boot Ultrix on DECstation? I have a 500/240 that I’d love to try. I might also try to use mopd to NetBoot my Multia, as my particular firmware is pretty buggy with tftpd.

- Alex

[dreamlayers]

My DS3100 and DS5000/125 both have non-functioning power supplies, probably due to bad capacitors. So I have not tried to boot a DECstation.

[fjkraan]

Congratulations with this cool result!

Some time ago there was an discussion on alt.sys.pdp11 (https://groups.google.com/g/alt.sys.pdp11/c/4wGZUJnYoMY) on netbooting a PDP-11. As I happend to have an M8189 (11/23+), 2 Mbyte RAM and a M7504 (DEQNA) in a rack and not much else, netbooting this sounds like fun . But I realize booting Ultrix on a Vax is something different from booting an O.S. as RT-11 on a PDP-11.

[bqt]

Congratulations with this cool result!

Some time ago there was an discussion on alt.sys.pdp11 (https://groups.google.com/g/alt.sys.pdp11/c/4wGZUJnYoMY) on netbooting a PDP-11. As I happend to have an M8189 (11/23+), 2 Mbyte RAM and a M7504 (DEQNA) in a rack and not much else, netbooting this sounds like fun . But I realize booting Ultrix on a Vax is something different from booting an O.S. as RT-11 on a PDP-11.

You can netboot RSX-11S. It was designed for exactly that purpose.

[dreamlayers]

I got my DECstation 3100 working and tried some things. You can't netboot MIPS Ultrix using mopd because it uses ECOFF file format and only Ultrix mopd understands that. I also couldn't netboot NetBSD using the main mopd branch I was working on. Though there is another mopd version from mips-linux which could netboot NetBSD 1.4.1 https://archive.netbsd.org/pub/NetBS...nel/install.gz. I have that in another branch at https://github.com/dreamlayers/netbsd-mopd/tree/mwr. It is originally from ftp://ftp.linux-mips.org/pub/linux/m...le/macro/mopd/.

I couldn't get TFTP boot to work, or maybe more precisely BOOTP didn't work. The DECstation 3100 makes a BOOTP request, gets a response, and then just waits a bit and makes more BOOTP requests. There are no other outgoing packets besides the BOOTP requests. I've read that some ROMs are buggy and it's hard or impossible to do a TFTP boot.

Maybe one could use binutils to objcopy from ECOFF to a.out or ELF, and then use those with mopd.

[kiwi.jonathan]

I'm pretty sure that netbooting a 3100 worked at some point, though I forget whether it was MOP or bootp/tftp. There are different ROM implementations, with different sets of bugs. I believe some flavor of open-source mopd supported ECOFF, that's why NetBSD does/did an "elf2ecoff" on its kernel binaries as the last step.

I haven't fired up a 3100 in about 20 years, but I'm just reviving a 5000 /260 and a /150, intending to work on FDDI (DEFTA). I can try a 3100 while I'm at it.

It _may_ be that for your 3100 PROM with TFTP, you need to set up proxy-ARP for the booting machine's IP-addr. It's been a while