question about gcc

Friedrich Manfred fm@sat-automation.com
Mon Jan 31 16:09:00 GMT 2000


Dear developers

We have a big problem. Perhaps you can help us.

Our company develops on a new embedded automation board.
A software tool on a PC generates an application code in C which should be
compiled, linked and loaded down to the embedded automation board. 
The CPU on this board is a Intel 386EX processor running on a selfmade OS.
This OS (written in C) is running in protected mode ,uses the multi
segmented model based on the global descriptor table from the 386EX

Until now we have used the Watcom C/C++ compiler (version 10.5) with the
memory modell small (CS <> DS) to compile the application code. 
So we have two entries in the GDT, for the CS and the DS.
But now the compiler is in the  "end of life " state (e.g. we have problems
and no support)  and we want to change our compiler to the GCC.

Our problem is that the code produces by the GCC is flat e.g.  CS = DS. 

For example:

DATA declaration:         unsigned int help;

Function:		void test (void)
			{
			help=5;
			};

			unsigned int help1;

			void test1 (void)
			{
			}

linked outputs by GCC:		adresses	test    	0
CS = DS
						help   	0x13	
						test1  	0x15
						help1 	0x28

linked outputs by watcom:           adresses	test    	0
CS <> DS	
						help 	0
						test1	0x13
						help  	2


Now our question to you is:
Is it possible to configure the GCC, that CS <> DS (similar the Watcom
compiler in the small memory model).
Please give us an answer if you any solution or not. Its very important and
urgent for us.

Thank you 

with best regards


> Manfred Friedrich
> 
> VA TECH SAT GmbH & Co
> Ruthnergasse 1
> A-1210 Wien
> 
> Phone: (+43/1) 29129 4930
> Fax: (+43/1) 29129 4340
> E-Mail: fm@sat-automation.com
> Internet: http://www.sat-automation.com
> 
> 



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