Re: debugging a kernel that doesn't start

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Sep 12, 2022 at 09:17:52PM +0200, Edgar Fuß wrote:
> I'm trying to run NetBSD on a Dell PowerEdge R6515, and the kernel is being 
> loaded (PXE or USB) but then the machine hangs hard.
> 
> What's the way to debug a kernel that hangs so early that you can't printf 
> or drop into ddb? I guess that's a phenomenon quite common for a new port 
> or changes to locore.s (or whatever that's called today), but it's completely 
> new to me.
> 
> I have virtually no clue about PeCee hardware. At the point the kernel is 
> started, are BIOS routines still available?

If you can setup a serial console, it may make things much easier.
I almost always use serial consoles on dev machines; I don't remember the
details but doing the equivalent of a putchar very early was possible.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--