Re: Improving bare-install

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

On Tue, 13 Nov 2018 at 01:06, Chris Hanson <cmhanson%eschatologist.net@localhost> wrote:
>
> I’ve acquired an HP 9000/425t and one of the systems I want to put on it is NetBSD. I’m starting with 8.0 under the assumption using the most recently released not-in-development version will be the most-supported route.

"Probably" :) though you should probably switch to current once you
start making changes (assuming it works for you)

> I’ve managed to netboot the 425t from my Mac and can run both of the available boot programs, SYS_UBOOT and SYS_INST. However, neither of them will let me easily install via the NetBSD 8.0 hp300 ISO, which is what I was hoping for. I also can’t just put miniroot.fs onto a CD-ROM and tell SYS_INST to install it to the swap partition from there, because miniroot.fs is a filesystem image rather than a partitioned device image.
>
> Given that, does anyone who knows more about the constraints under which they operate have an idea of what it would take to make it easier to get a bare install working? I can see a couple of routes to start with:
>
> (0) When generating the ISO maybe don’t gzip the kernel or miniroot.fs to make the below easier.
>
> (1) Make SYS_UBOOT support booting from a kernel on an ISO-9660 image, e.g. when it asks for a kernel allow typing in sd5:/hp300/binary/kernel/netbsd_RAMDISK and make it feasible for that to boot.
>
> (2) Make SYS_INST support installing a miniroot from a raw device, e.g. if I just burn miniroot.fs onto a CD-ROM and tell SYS_INST the SCSI ID of the CD-ROM drive, it should be able to look at the device contents and install the miniroot.fs from there.
>
> (3) Make SYS_INST support installing a miniroot.fs from an ISO-9660 image, e.g. let me type sd5:/hp300/installation/miniroot/miniroot.fs as the location of the miniroot.
>
> (4) Make the ISO itself bootable. I think this would require at minimum wrapping it in an oldschool HP partition layout/filesystem, so SYS_UBOOT and/or SYS_INST could be loaded from it. It’d probably also require at least some if not all of the above.
>
> (5) Provide netboot-to-install instructions in addition to netboot-diskless-workstation instructions. I’m trying to figure out how to do an install when netbooted; my impression is that I should be able to boot via NFS and then start an install on local disk somehow. But I’m not entirely sure how.
>
> Anyone have any suggestions, walkthroughs, “no way that could be made to happen, we only have space for 12KB of code” comments, etc.? Thanks!

If space turns out to be a limitation we could easily split the
inst/uboot functionality into more files, but I would not expect that
to be needed.

1) and 3) would involve adding ISO-9660 support to inst/uboot (which
strangely enough NetBSD already has in libsa and used by other ports
:) and would probably be a good place to start.

For 0) - both inst/uboot should have support for gzipped
miniroot/kernels already, so we should be good.

How do you feel about poking at code? :-p

The inst/uboot sources live in sys/arch/hp300/stand

(Apologies if you already know this bit)

You should be able to easily cross build NetBSD/hp300 from your mac by
downloading the source and running "./build.sh -U -m hp300 build"

Once you have a build you should find the tools in
.../obj/tooldir.something-something-something/bin

You can then edit the source for uboot or inst and quickly rebuild by
running nbmake-hp300 (from that bin dir)

sys/arch/vax/boot might be a good place to look for some sample code
for cd9660 handling

Mmm, I've just taken a look in sys/arch/hp300/common/conf.c... its a
little gnarly in there, so probably due a refactor :-p

David