Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!asuvax!ncar!boulder!hartzell
From: hartzell@boulder.colorado.edu (George Hartzell)
Newsgroups: comp.sys.mips
Subject: RISC/os core files.
Message-ID: <17983@boulder.Colorado.EDU>
Date: 8 Mar 90 22:58:58 GMT
Sender: news@boulder.Colorado.EDU
Reply-To: hartzell@boulder.colorado.edu (George Hartzell)
Distribution: na
Organization: University of Colorado, Boulder
Lines: 40


I just went around and around trying to get a program to read a
RISC/os 4.01 core file.  Here is the format of a core file according
to core(4). [u is a struct user]

beginning of file		-> -------------

struct user			   NBPG * UPAGES

				-> -------------

data pages			   NBPG * u.u_dsize

				-> -------------

stack pages			   NBPG * u.u_ssize

end of file			-> -------------

I learned several things.

1) NBPG is the same as NBPC, and UPAGES is the same as USIZE.

2) The struct user at the beginning of the file is the one described
in /usr/include/sys/user.h, not the (very different) bsd one described
in /bsd43/usr/include/sys/user.h.  It would be helpful if MIPS would
lobotimize /bsd43/usr/include/sys/user.h like they did for the bsd43
utmp.h so people don't get bitten by this.

2) The data pages do *NOT* start at NBPG*UPAGES (or NBPC*USIZE).
They start at NBPG * 1.

Hope that this might save someone some frustration.

g.


George Hartzell			                  (303) 492-4535
 MCD Biology, University of Colorado-Boulder, Boulder, CO 80309
hartzell@Boulder.Colorado.EDU           ..!ncar!boulder!hartzell