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From: dwm@encore.Encore.COM (Dave Mitchell)
Newsgroups: comp.sys.encore
Subject: Re: problems with undump on Encores
Message-ID: <10202@encore.Encore.COM>
Date: 25 Oct 89 17:27:30 GMT
Sender: news@Encore.COM
Lines: 48

In article <2511@goanna.oz> isaac@goanna.oz (Isaac Balbin) writes:
>Well, I do have three versions of undump which used to work
>properly on our two encores. Two were for BSD and the other for SYSV.
> ...
>The operating systems we are using are Umaxnfs 4.2 (B3_3.21) and
>UMAX V 2.2H R3.1
>
	The format of core files was changed to so that any
	shared memory regions would also be available through
	the core file.  I believe this change was made with
	BSD release 3.3 and SysV release 2.2.  You will need
	to rebuild undump; some minor source changes may be
	needed.  Consult /usr/include/sys/ptrace.h for detailed
	information about the new core file format.  Enclosed
	below is a pictorial sketch of the core layout, stolen from
	ptrace.h:

	The ptrace_user structure is found at the beginning  of core files.
	The layout of a Umax core file is as follows:  

	+-------------------------------+ 0
	|	struct ptrace_user	|
	+-------------------------------+ sizeof(struct ptrace_user)
	/////////////////////////////////
	+-------------------------------+ <===== ptrace_user.pt_memptr
	| pt_mem_desc[ pt_nmem ]        |
	+-------------------------------+
	/////////////////////////////////
	+-------------------------------+ <===== ptrace_user.pt_dataptr
	|	data			|
	+-------------------------------+ ptrace_user.pt_dataptr + dsize
	|	stack			|
	+-------------------------------+ ptrace_user.pt_dataptr+dsize+ssize
	|	extra memory 0		| optional
	+-------------------------------+  ... + pt_mem_desc[0].pt_mem_size
	|	extra memory 1		| optional
	+-------------------------------+  ... + pt_mem_desc[1].pt_mem_size
	|       etc.			| optional
	+-------------------------------+

	Notice that the three or more components are contiguous and
	no padding or alignment is used.  

	The extra memory regions are all the shared memory regions and
	shared library data regions.

Dave Mitchell	Usenet:		...!{bu-cs,decvax,necntc,talcott}!encore!dwm
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