kern/74977: dcons.ko requires KDB support

[Ulrich Spoerlein]

>Number:         74977
>Category:       kern
>Synopsis:       dcons.ko requires KDB support
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Sun Dec 12 11:00:51 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Ulrich Spoerlein
>Release:        FreeBSD 5.3-RELEASE-p2 i386
>Organization:
>Environment:
System: FreeBSD coyote 5.3-RELEASE-p2
>Description:
kldload dcons will fail for the GENERIC Kernel, because the gdb_cur
symbol is missing. The module Makefile unconditionally defines KDB and
ALT_BREAK_TO_DEBUGGER

/sys/modules/dcons/Makefile:
opt_ddb.h:
        echo "#define KDB 1" > $@

opt_comconsole.h:
        echo "#define ALT_BREAK_TO_DEBUGGER 1" > $@

Therefore, on kldload you get: kernel: link_elf: symbol gdb_cur undefined

This leads to dconschat(8) becomes useless without recompiling the
kernel.
>How-To-Repeat:
Boot GENERIC, kldload dcons
>Fix:
Remove those two 'echo defines' from the Makefile, rebuild the module,
dconschat(8) starts working! :)

I don't know if this is the right fix however. Is KDB needed on the
_client_ to debug the _servers_ Kernel via dconschat?
>Release-Note:
>Audit-Trail:
>Unformatted: