nice.  seems so obvious now.

Fri, Mar 04, 2005 at 10:59:02AM +0000, Steve Woodford:
>  >  first, the server does not respond to ping and getty does not respond
>  > on the console.  It does appear as if, from _load_mbuf, it enters
>  > pmap_extract, though it does not show-up in the trace.
>  
>  Can you try the attached patch to sparc64/machdep.c please?
>  
>  Cheers, Steve
>  
>  
>  --Boundary-00=_X9DKCZxpK1eAenk
>  Content-Type: text/x-diff;
>    charset="iso-8859-1";
>    name="sparc64-machdep.c.diff"
>  Content-Transfer-Encoding: 7bit
>  Content-Disposition: attachment;
>  	filename="sparc64-machdep.c.diff"
>  
>  Index: machdep.c
>  ===================================================================
>  RCS file: /cvsroot/src/sys/arch/sparc64/sparc64/machdep.c,v
>  retrieving revision 1.177
>  diff -u -r1.177 machdep.c
>  --- machdep.c	30 Jan 2005 16:56:26 -0000	1.177
>  +++ machdep.c	4 Mar 2005 10:57:00 -0000
>  @@ -1113,9 +1113,6 @@
>   		vaddr_t vaddr = mtod(m, vaddr_t);
>   		long buflen = (long)m->m_len;
>   
>  -		if (buflen == 0)
>  -			continue;
>  -
>   		len += buflen;
>   		while (buflen > 0 && i < MAX_DMA_SEGS) {
>   			paddr_t pa;
>  
>  --Boundary-00=_X9DKCZxpK1eAenk--
>