Re: 1.6 & -current miniroot: grey screen after loading kernel

[Aymeric Vincent <Aymeric.Vincent%labri.fr@localhost>]

Hubert Feyrer <hubert.feyrer%informatik.fh-regensburg.de@localhost> writes:

> May I (please!) suggest to put a second, smaller, kernel on the miniroot,
> so people who want to install on a small-memory(?) machine can install
> NetBSD? Just requiring them to boot a different kernel (name) should be
> ok...

I would rather suggest that we fix the bug. I'm (kind of) volunteering
although I don't promise a quick solution.

I plugged my Amiga again yesterday, and the problem comes from the
fact that the kernel is loaded in "low" fast memory (i.e. 0x200000).
On startup, the physical memory is mapped transparently in addition to
the other mappings needed to setup the VM subsystem.

So, if your kernel is smaller than 0x200000 bytes, its physical
addresses will fit below the barrier where physical memory gets
mapped and things will happen to work (with a little bit of luck,
too, because the kernel is not the only thing mapped). If your kernel
has addresses above this barrier, some memory mappings will clash, and
"anything can happen".

If someone puts up a miniroot with a small kernel as an interim
solution, please describe the problem as being "you have memory at
0x200000" and not "you have too little memory".


FWIW (i.e. nothing), the kernel crashes when it memset()s at
proc0paddr, but the problem is obviously not strictly speaking there.

Kind regards,
 Aymeric