Re: 43p: Install kernel boots, generic not

[Ulrich Teichert <lists%ulrich-teichert.de@localhost>]

Hi,

[del]
> Would you mind if I recap my understanding - its possible I'm missing
> something...
> 
> (Please treat all of this as enthusiastic cheerleading from the sides -
> you're the one poking at the kit, so feel free to tell me to calm down :)

No problem. I like to write the stuff down, that gets me thinking it over
again.

> Taking a quick dig into sys/arch/prep/stand.  boot/conf.c seems to indicate
> the NetBSD/prep bootloader only supports booting from scsi, and
> specifically from the copy of boot/siop.c which is driving the 53c810
> chipset directly

Yes, but that code isn't working and according to the commit message was
only experimental. See the thread:

"NetBSD 8.10 does not boot on 7043-140"

My first mail to this group on the 31.5.... The solution is in:
<201907011749.x61Hn5ea003050%valdese.nms.ulrich-teichert.org@localhost>
same thread.

BTW, should I mail the port-prep maintainer the patch? What would be
the preferred process to get that one-line patch integrated into the code?

> If Kernels <2M can be booted from the NetBSD bootload prompt (is this the
> case?) then that implies one of
> - The NetBSD bootloader code has issues reading files >2MB
> - Its loading into an area of memory which is only contiguous only up to 2M
> - Something else is happening which I missed :)
[del]

It's something else ;-) The bootloader with the attached kernel gets loaded
by the firmware and just unpacks the kernel to the start address. If that
file (which is the product of mkbootimage) is over 2MB, the firmware seems
to have a wrap-around and overwrites the already written bytes in memory.

I've played with yaboot, but that code only builds on Linux and looks
un-maintained. After fixing a few issues, I could get the grub2 build
running, but I was too tired yesterday evening...

CU,
Uli
-- 
Dipl. Inf. Ulrich Teichert|e-mail: Ulrich.Teichert%gmx.de@localhost | Listening to:
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