Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!naitc!ddsw1!hb
From: hb@ddsw1.MCS.COM (Henry Barta)
Newsgroups: comp.sys.intel
Subject: Re: iC86 absolute mapping of vars
Message-ID: <1990Sep14.023548.19241@ddsw1.MCS.COM>
Date: 14 Sep 90 02:35:48 GMT
References: <9779@discus.technion.ac.il>
Reply-To: hb@ddsw1.MCS.COM (Henry Barta)
Organization: ddsw1.MCS.COM Contributor, Wheeling, IL
Lines: 17

In article <9779@discus.technion.ac.il> dario%techunix.bitnet@lilac.berkeley.edu (Dario Ringach) writes:
>
>Does anyone know how to place an iC86 variable at a specific
>absolute address?  Thanks.

I don't know of any way to do this through the compiler. When I had to
address memory mapped I/O in an embedded system, I declared the variable
as 'extern' in the '.c' file. To locate it, I created an '.asm' file
that listed the same variable name as an 'EXTRN' and then located it
within a segment using an 'ORG' statement. The segment was then placed
at the proper location when the program was located ('XLOC86') following
linking ('XLINK86'). If you are targetting DOS or iRMX you may succeed by
declaring a pointer to the memory location you wish to access and then
dereference it. iC86 has functiona that can be used to assign an address
to the pointer.

hank