🚀 go-pugleaf

In article <1989Oct16.225206.22386@paris.ics.uci.edu> Ron Guilmette <rfg@ics.uci.edu> writes:
>In article <6535@pt.cs.cmu.edu> lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) writes:
>>About the only hardware feature I used to pray for was "breakpoint at
>>data address". ...
>I noticed that the i860 has this feature on-chip.  ...
>Now if we could just get support for such things via standard UNIX ptrace
>calls, and then get the GNU Debugger (gdb) to actually bring such facilities
>out to the user's level...

Some of us low-budget types feel pretty lucky.  The 80386 can trap up to four
memory addresses, separately monitoring each for fetch, read, or write.
When this feature is in use your program runs slower, but it's a heck of
a lot faster than instruction at a time tracing.

Astonishingly, AT&T System V/386 ptrace() lets you read and write the debug
registers (take that, you Berkeloids) that control this swell feature.
I keep meaning to teach gdb how to use them.  Maybe somebody else already
has.
-- 
John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 864 9650
johnl@esegue.segue.boston.ma.us, {ima|lotus|spdcc}!esegue!johnl
Massachusetts has over 100,000 unlicensed drivers.  -The Globe