Linux on VAX - Dead ?

[babydr DBA James W. Laferriere]

On Fri, 17 Mar 2023, Jan-Benedict Glaw wrote:
> Hi!
> On Thu, 2023-03-16 13:56:27 -0800, babydr DBA James W. Laferriere <babydr at baby-dragons.com> wrote:
>> On Sun, 15 Jan 2023, Jan-Benedict Glaw wrote:
>>> On Sun, 2023-01-15 01:18:27 +0000, Maciej W. Rozycki <macro at orcam.me.uk> wrote:
>> ...snip...
>>> While the Linux port is a sad story as it somewhat came to an end, at
>>> least the system availability may get better. You know, I was long
>>> searching for a room to setup my old system to be 100% operated
>>> remotely. I'm actually negotiating something right now. :) So hope is
>>> there that this may actually become a reality!
>>>
>>>  The VAX port, as is, is pretty dead. I wouldn't try pulling in newer
>>> Linux patches into our former tree, but use our arch stuff to add it
>>> to current Linux. And glibc? What were the most "interesting" issues?
>>> ISTR that it was threading and possibly a TLS ABI?
>>
>> 	Are you saying the Vax-linux porting is dead as in never to be ?
>
> I still would love to see Linux support VAX systems, with Linus's
> upstream kernel having everything needed. The old/former port's
> sources are there, but I think it'll be a non-trivial task moving this
> source forward. So the (old) port is indeed dead.
>
>  OTOH, Maciej did great work to improve/revamp GCC's VAX support.
> These improvements didn't even yet arrive at NetBSD. (Indeed, I've
> recently used NetBSD on SIMH VAX and it basically just works.) So with
> compiler support getting _better_ for a long-dead ISA, at least one
> operating system around that actively can use this, and a former Linux
> port that can be used to start a _new_ Linux port.
>
>  We learned a lot from the last attempt. I think the most important
> part is that we need a working GNU libc quite early. Most of that is
> quite easy (ie. just use old/existing code to do syscalls, define a
> few macros, use all-standard C-coded library functions instead of
> specifically coded VAX assembler variants), but some pieces are not so
> trivial. We _need_ to define and implement a TLS ABI. And libm may or
> may not be an issue, given that VAXen use a
> different-to-what-is-usual-today representation of floating point
> numbers. Basically, all of today's computers use the IEEE-754
> representation of floating point numbers, along with this spec's
> concept of infinity, rounding, ...  VAX is slightly different, which
> in the past broke program's assumptions about how floating point
> numbers work more than once.
>
>  So... Linux on VAX is dead.  GCC for VAX is more vivid than ever
> before. Linux on VAX is possible.
>
> MfG, JBG

 	This is actually Very good to hear .  Was of the impression that we were 
at a point of no return from messages previously received .

 	As you were recounting that you are working on a remote site to have 
your system(s) available to you remotely ,  I am hoping that has or is well on 
its way to fruition .

 	Please keep the list posted on ANY items that are of issue(s) ?
 	With luck and availability of resources we can help .

 		Tya ,  Twyl ,  JimL

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