Re: boot issue on NetBSD/vax 8.x and 9.x

[David Brownlee <abs%absd.org@localhost>]

On Tue, 24 Jan 2023 at 14:02, Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost> wrote:
>
> I wrote:
>
> > So it has never worked on any VAXen with only 8 MB memory.
> > Just changing the RELOC value to 0x7e0000 makes bootloader work again
> > on my 8 MB VS3100/m30.
>
> Ah, I was a bit stupid.
> 0x7e0000 makes bootloader starts, but it fails on loading a kernel,
> maybe due to lack of heap memory for FFS blocksize.
>
> With RELOC=0x7d0000 it can load at least 10.99.2 custom kernel:

Nice sleuthing :)

This sounds like it should be viable to be pulled up into netbsd-8 and
netbsd-9 if it all checks out, which is even better VAX news!

(I wonder how hard it would be to make the bootloader load at a low
memory address and then probe memory & relocate itself up high out of
the kernel space, though that would probably only be useful for 4M or
6M machines, which is now very much an extreme target for recent
NetBSD...)

Thanks

David