NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c++-part2/16552

Internet Message Format | 1996-08-05 | 1.7 KB

Path: grimsel.zurich.ibm.com!usenet
From: [e-mail] (Keith Whittingham)
Newsgroups: comp.lang.c++
Subject: Re: Far Calls
Date: 11 Apr 1996 08:42:51 GMT
Organization: IBM Research, ZRH
Message-ID: <4kigmb$[e-mail]>
References: <4kgvf1$[e-mail]>
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In <4kgvf1$[e-mail]>, [e-mail] (Jason) writes:
>For any CS Majors, Junior and above...
>    How do you make a far call to a SPECIFIC address in C/C++.  We must
>write a monitor for class, with the ability to modify EXACT memory
>locations and execute the code from a given location.  Also, is anyone
>familar with the REGISTER command?  It says it will load the value
>directly into a register, IF POSSIBLE.  Now, does this if possible
>give you a indicator that it has?  If not, is there a way TO ALWAYS
>load into a register.  This program is basically supposed to be MS
>DEGUB but designed and written by us.  So far, these are the only 2
>stumbles I have come across.

Far calls: do you really want to do this, can you tell that the
linkage of the called location is correct. The 'standard' PC way (and
I use the word standard loosly) is to load an interrupt vector with
the address of a routine that needs calling and generate a software
interrupt (e.g. int86)..

Register: I think you're misinterpreting the keyword. Register is
used for optimisation purposes. Using the register modifier tells
the compiler that this variable is being used a lot and it should
keep it in any register it chooses (if it can) to make things
operate faster.

If you want to load registers and call functions directly then
either use int86 or use inline assembler.

Keith