Robert V. Baron   writes:
>"Erik E. Fair" <fair@clock.org> writes:
>...
>> In addition, Jonathan Stone has suggested that a "halt" command be added to
>> the generic DDB command set, with a rough interpretation of "return control
>> to whatever PROM monitor exists on this machine".
> 
>It would also be nice to have a command that tries to sync the disks,
>before you halt and/or reboot.

i think there are two independent variables here:
  1) sync disk vs. dont sync disks
  2) try to reboot instead of going to PROM monitor 
     (i'll ignore a hard halt, as in HALT insn, for now)

and rebooting without synching is ... gross.
So  there are really three cases:

   * "reboot":  sync disks,  then ask prom to reboot.
   * "halt":    sync disks, then drop to prom.
   * "prom":    no sync, straight to prom 
     (prom may have extra smarts or be able to resume kernel)

ddb has the first, its called "reboot". 

Several ports have one or other of the other two.  I think adding both
as MI commands would be worthwhile.  For machines like i386 (and
hp300s? I forget) where there's no prom UI, then this distinction
makes no difference and it can be ifdefed out.

We should be able to do this so the marginal cost is well under 100
bytes.

I also suggested "where" as a synonym for "trace".