Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84 exptools; site ho95e.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!houxm!ho95e!wcs
From: wcs@ho95e.UUCP (x0705)
Newsgroups: net.lang.c,net.unix-wizards
Subject: Re: (3b2) functions in data space
Message-ID: <556@ho95e.UUCP>
Date: Wed, 12-Mar-86 01:17:07 EST
Article-I.D.: ho95e.556
Posted: Wed Mar 12 01:17:07 1986
Date-Received: Fri, 14-Mar-86 03:42:04 EST
References: <728@petsd.UUCP> <1486@devwrl.DEC.COM> <622@bentley.UUCP>
Reply-To: wcs@ho95e.UUCP (Bill Stewart 1-201-949-0705 ihnp4!ho95c!wcs HO 2G202)
Organization: AT&T Bell Labs, Holmdel NJ
Lines: 20
Xref: watmath net.lang.c:8128 net.unix-wizards:17164

In article <622@bentley.UUCP> kwh@bentley.UUCP (KW Heuer) writes:
>....
>The person who started this discussion was already able to create code
>in the .data space; whether it's done by the loader or at run-time by
>the program is irrelevant.  The question is whether it's possible to
>_execute_ such a function.  On a vax, you can.  On a pdp11 with split
>I/D, you can't, because .text and .data addresses are each 16 bits,
>so an attempt to call a function from .data space will actually call
>the function at the same address in .text space.  (The workaround is
>to use ld -N, so you don't have split I/D.)  The remainder of this
>discussion focuses on the 3b2, where .text and .data addresses have
>separate ranges (.text normally starts at 0x80800000, .data at
>0x80880000).				     ^^^^
   ^^^^

(-: Obviously, you can't execute the data as code - the .data resides on
the 8088, while the .text is on an 8080.  No wonder the floating point
was so slow!
-- 
# Bill Stewart, AT&T Bell Labs 2G-202, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs