kernels built from netbsd-4 and netbsd-wrstuden-fixsa hang after loading

["Greg A. Woods; Planix, Inc." <woods%planix.ca@localhost>]

I've just had a second kernel hang immediately after loading.

The first was built from the netbsd-wrstuden-fixsa branch updated  
early last week.  The previous working kernel from that branch was  
built 2008/04/04.

The second kernel just now was built from the netbsd-4 branch updated  
late last week.  The previous working kernel from that branch was  
built 2008/03/04.

The kernel configs in both cases are basically GENERIC.MP

The system is unresponsive to BREAK and NMIs from the front-panel  
reset switch are ignored too thus requiring a full power cycle.  (good  
job I'm not working from remote!)

[Mon Aug 18 11:25:43 2008]
[Mon Aug 18 11:25:43 2008]>> NetBSD/i386 BIOS Boot, Revision 3.3
[Mon Aug 18 11:25:43 2008]>> (woods@once, Tue Mar  4 18:26:10 EST 2008)
[Mon Aug 18 11:25:43 2008]>> Memory: 637/3931008 k
[Mon Aug 18 11:25:43 2008]Press return to boot now, any other key for  
boot menu
[Mon Aug 18 11:25:43 2008]booting hd0a:netbsd - starting in 0
[Mon Aug 18 11:25:48 2008]9295832+411684+373836 [439152+421725]=0xa712bc
[-- break #1 sent -- `\z' -- Mon Aug 18 11:38:28 2008]
[-- break #1 sent -- `\z' -- Mon Aug 18 11:38:30 2008]
[-- break #1 sent -- `\z' -- Mon Aug 18 11:38:36 2008]


The machine in this case is a Dell PE2650 with 2 processors and 4GB of  
RAM.

As far as I can tell no changes were made locally to the kernel  
sources in the intervening time.


If anyone has any idea what might have been pulled up to the netbsd-4  
branch since March or April (and subsequently merged to the wrstuden- 
fixsa branch) which might cause such a hang, please help me find and  
fix it!

--
                                        Greg A. Woods; Planix, Inc.
                                        <woods%planix.ca@localhost>