SRM error "kernel stack not valid halt" after rebooting FreeBSD 5.3 on AS2000

[Matthew X. Economou]

Speaking of boot problems, when I reboot my AlphaServer 2000 (running
FreeBSD 5.3-RELEASE), the firmware loops, repeating the following
messages:

	halted CPU 0

	halt code = 2
	kernel stack not valid halt
	PC = 0

	CPU 0 restarting

I cannot break into the console (neither via control-C, nor via a serial
line hard break).  I must hit the reset switch in order to continue.
This can be most inconvenient as I do not always have physical access to
this server.

Is this a problem with FreeBSD or with the firmware?  I realize I need
to upgrade 5.3-RELEASE-p5 at there are at least two security-related
bugs in 5.3-RELEASE.

A cursory Google search resulted only in a number of posts about trying
to install NetBSD, OpenBSD, FreeBSD, or Linux onto unsupported hardware.
This error only happens after I halt the operating system.

Best wishes,
Matthew 

-- 
"The challenge of a moral life is to do nothing that requires
forgiveness."  - Roger Ebert in his review of _The Woodsman_