Re: How do you use old versions?

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

On Fri, 7 May 2021 at 20:48, Alexander Bochmann <ab%lists.gxis.de@localhost> wrote:
>
> ...on Fri, May 07, 2021 at 06:32:53PM +0100, David Brownlee wrote:
>
>  > Testing ideas based on comments so far:
>  > - 7.0, 7.1, 7.2 & 8.0 kernels (as mentioned before, this should all be
>  > possible from a single 7.x install and just switching boot kernels)
>
> I did most of that pretty much a year ago, but my notes from that
> are not complete.
>
> 7.0.2: everything seems ok, though the installer is very tight
> on RAM, and depending on the phase of the moon setting up hard
> disk partitions runs out of memory (I think I went back to an
> 5.x installer in order to set up space for NetBSD on my new
> CF card).
>
> 7.2: doesn't even boot the install kernel
>
> 8.0 and up: Install kernel boots, but userland throws "floating
> point exception" left and right. Someone wrote back then that
> other mips softfloat platforms seem to have a similar problem.
> PCMCIA cards are detected, but none of them work (ne2k keeps
> sending  "ne0:  where did the card go?", xi has no carrier
> detection, everything wireless is a fail - didn't try PCMCIA
> storage).
>
> 9.x: Pretty much the same, except now CF storage is wonky too.
>
> Anyways, I'll try to do some more organized testing tomorrow
> and will feed in the results. Maybe it'll turn out that it's
> better to abandon the hpcmips platform (or at least the z50
> as supported system) instread of trying to fix all the mess
> (I can do bug reporting and test builds and such, but I'm not
> a programmer, much less when hardware is involved).

It's possible, but 48MB is still a reasonable target for a small system.

Some issues can be approached independently:
- CF issues: definitely attack this with a newer kernel with known
good older userland. Likely to be a blocker for many other issues
- pcmcia network/storage: again, newer kernel, known good userland
(Serial slip/ppp networking would still work for the masochistic)
- userland floating point issues: Userland should not be newer than
kernel, so limited to testing install images until CF issue resolved)

If you have a nice fast build box then once you have narrowed down
which release started showing the CF & pcmcia issues, I would
probably:
- clone the NetBSD git mirror
- update to current around the time of the working release
- run "./build.sh -u -m hpcmips kernel=GENERIC" and test the generated
kernel with a known good netbsd 7.0.2 install userland
- run "git bisect good" or "git bisect bad" based on the result (or
"git bisect skip" if it did not build)
- either update to around time of the following (result was good) or
earlier release (result was bad) and repeat build, test & git bisect
- git will now binary search for the earliest version which shows the issue

David


David