kern/72639: 5.3-BETA7 kernel config option ALT_BREAK_TO_DEBUGGER doesn't work

[John Engelhart]

>Number:         72639
>Category:       kern
>Synopsis:       5.3-BETA7 kernel config option ALT_BREAK_TO_DEBUGGER doesn't work
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Oct 13 13:10:23 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     John Engelhart
>Release:        5.3-BETA7
>Organization:
>Environment:
FreeBSD new.zang.com 5.3-BETA7 FreeBSD 5.3-BETA7 #0: Mon Oct 11 00:12:17 EDT 2004     johne at new.zang.com:/usr/src/sys/i386/compile/new  i386
>Description:
The kernel config option ALT_BREAK_TO_DEBUGGER doesn't seem to work on 5.3-BETA7.

>From my kernel config:

options         KDB, KDB_UNATTENDED, KDB_TRACE
options         ALT_BREAK_TO_DEBUGGER   # Use <CR>~^b to enter debugger on
                                        # the serial port
options         PANIC_REBOOT_WAIT_TIME=300

It looks like the kernel debugger parts changed from 5.2.1 to 5.3, though, and this may just be that I didn't follow all the details of what's changed.  Previously, instead of KDB, my 5.2.1 config had DDB and all worked well.

I've been having ethernet hangs and the debugger didn't seem to want to come up when I'd have the problem.  So, after the last round, I tried it when the system had rebooted and was running fine.  Didn't drop to debugger then, either.

Perhaps I missed something in the 5.2.1 to 5.3 debugger transition.  If so, can you post the simple/obvious fix to the kernel conf in case anyone else trips up on this like I did?
>How-To-Repeat:

>Fix:
      
>Release-Note:
>Audit-Trail:
>Unformatted: