Re: Two questions about the Vax installation guide...

[Johnny Billquist <bqt%softjar.se@localhost>]

On 2025-08-05 20:50, Anders Magnusson wrote:
> Den 2025-08-05 kl. 06:45, skrev Johnny Billquist:
> > On 2025-08-04 15:32, Anders Magnusson wrote:
> > > Den 2025-08-04 kl. 15:27, skrev Martin Husemann:
> > > > On Mon, Aug 04, 2025 at 09:06:56AM -0400, Perry Metzger wrote:
> > > > > (It's also not clear what the distinction between boot and boot.mop 
> > > > > is...)
> > > > boot is elf format and not all mopds can handle it (our in-tree one
> > > > can use it just fine).
> > > >
> > > > boot:     ELF 32-bit LSB executable, Digital VAX, version 1 (SYSV), 
> > > > statically linked, stripped
> > > > boot.mop: data
> > > Yep, intended for people net-booting from VMS.  Not so common these 
> > > days though.
> > > (Maybe Johnny?  Can you mop-boot NetBSD from RSX? :-) )
> >
> > Interesting question. I would expect so, but you'd need to get the 
> > image in the proper format for the RSX MOP server. Doable, but I doubt 
> > there is enough interest to go down that path. :-)
> >
> > But if someone really wanted to, I guess I could create a tool to 
> > convert images. VMS would use the same image format, I believe. 
> > DECserver images from DEC were possible to be provided from both RSX 
> > and VMS by the same file.
> The boot program is available in MOP format.  Would that work? :-)
>
> https://archive.netbsd.org/pub/NetBSD-archive/NetBSD-1.4/vax/ 
> installation/netboot/boot.mop

The kernel itself should be possible to feed using the mop server as 
such. But the boot program needs to be taught how to request and accept 
a kernel image using MOP.

But those images can't be used by VMS or RSX, as far as I know. They 
require a different format for their MOP servers to be able to feed the 
file. That's the tool I was suggesting I could create if needed.
Basically, for RSX and VMS, the images accepted by the MOP server needs 
to be task files as RSX defines them, but images built without a header 
(unless you know RSX that might mean pretty much nothing). Basically, 
there is a 1024 byte header with various information about load address, 
start address, versions and dates and stuff in the first two blocks (512 
byte blocks that is), and then comes the actual binary pretty much raw.

  Johnny

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