Setting a dump device from db> ?

[Rodney W. Grimes]

> On Mon, Dec 19, 2016 at 02:16:25PM -0700, Alan Somers wrote:
> > Is it possible to set a dump device from loader.conf or from the db>
> > prompt?  I'm trying to investigate a panic in mpr(4), but I can only
> > reproduce it during the boot, before rc(8) has set my dump device.  It
> > looks like ada(4) initializes before mpr(4), so I should be able to
> > dump to an ada device, if only I can figure out how.  If not, I
> > suppose I'll have to try gdb over firewire.
> 
> You can set "dumpdev=ada0p1" or so in loader.conf. See g_dev_init() and
> init_dumpdev(). This should probably be documented in loader.conf(5).

Please review and if OK commit

Index: sys/boot/forth/loader.conf
===================================================================
--- sys/boot/forth/loader.conf	(revision 310132)
+++ sys/boot/forth/loader.conf	(working copy)
@@ -101,6 +101,7 @@
 #prompt="\\${interpret}"	# Set the command prompt
 #root_disk_unit="0"		# Force the root disk unit number
 #rootdev="disk1s1a"		# Set the root filesystem
+#dumpdev="disk1s1b"		# Set a dump device early on for crashes during boot
 #tftp.blksize="1428"		# Set the RFC 2348 TFTP block size.
 				# If the TFTP server does not support RFC 2348,
 				# the block size is set to 512.  If the value
-- 
Rod Grimes                                                 rgrimes at freebsd.org