The DIAGNOSTIC problem, now fixed,  was caused by the src/common
bcopy merge, which led to a DIAGNOSTIC assertion against a bcopy
zero destination, which caused a panic (on macppc) before console
attachment. The old libkern bcopy allowed a 0 destination.

We might want to think about an explicit API for copies with a
destination that aliases NULL.

> From: Ross Harvey <ross@netbsd.org>
> Subject: CVS commit: src/common/lib/libc/string
> To: source-changes@NetBSD.org
> Date: Sun,  5 Feb 2006 06:47:48 +0000 (UTC)
> 
> 
> Module Name:    src
> Committed By:   ross
> Date:           Sun Feb  5 06:47:48 UTC 2006
> 
> Modified Files:
>         src/common/lib/libc/string: bcopy.c
> 
> Log Message:
> Don't do DIAGASSERT against NULL if _KERNEL This puts us back to
> kernel behavior before src/common where 0 was a valid dest addr.
> 
> This should fix the macppc (and other OEA ppc) silent-death-on-DIAGNOSTIC
> issue, and possibly other DIAGNOSTIC failures.
> 
> XXX it might be worth thinking about an API where 0 is allowed in
> documented cases and not allowed otherwise.
> 
> 
> To generate a diff of this commit:
> cvs rdiff -r1.1 -r1.2 src/common/lib/libc/string/bcopy.c
> 
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.