port-alpha/57720: kernel doesn't get symbol table when booted from qemu

[campbell+netbsd%mumble.net@localhost]

>Number:         57720
>Category:       port-alpha
>Synopsis:       kernel doesn't get symbol table when booted from qemu
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-alpha-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Nov 23 19:20:00 +0000 2023
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
The AlphaBSD Foundation
>Environment:
(qemu-system-alpha, qemu 8.1.0)
NetBSD  10.99.10 NetBSD 10.99.10 (GENERIC-$Revision: 1.418 $) #7: Wed Nov 22 17:20:45 UTC 2023  root@singbulli.local:/home/riastradh/netbsd/current/obj.alpha/sys/arch/alpha/compile/GENERIC.QEMU alpha
>Description:
1. qemu doesn't pass the same bootinfo records through to alpha_init that the NetBSD bootloader does, so the kernel is unable to find the symbol table.

2. The message that is supposed to be printed explaining this, including the text `boot program did not pass bootinfo', doesn't come through at this point, presumably because the bootstrap console doesn't work for some reason: https://nxr.netbsd.org/xref/src/sys/arch/alpha/alpha/machdep.c?r=1.376#435
>How-To-Repeat:
crash the kernel in qemu and try to print a stack trace in ddb
>Fix:
Yes, please!

Workaround: Use the GENERIC.QEMU kernel.  (But we should find a way to make this unnecessary -- and, until then, make the failure mode more obvious if you use GENERIC instead of GENERIC.QEMU.)