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From: Martin Day <Martin AT snsystems DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Putting 200k of data in an executable ?
Date: Tue, 17 Oct 95 22:41:11 GMT
Organization: SN Systems
Lines: 56
References: <resta-1310951051530001 AT mac-resta DOT iei DOT pi DOT cnr DOT it>
Reply-To: Martin AT snsystems DOT co DOT uk
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Dj-Gateway: from newsgroup comp.os.msdos.djgpp

In article <resta-1310951051530001 AT mac-resta DOT iei DOT pi DOT cnr DOT it>
           resta AT iei DOT pi DOT cnr DOT it "Giovanni Resta" writes:

> I will like suggestions on how to solve this problem.
> I made a program that make use of an external binary file of, say, 200k-300k.
> That is, the program starts, reads in memory this file,
> that is always the same (it does not change between executions) 
> and then proceed.
> I was wondering if I can use just one file, that is putting somehow the
> data inside the executable.
> 
> I remember that some years ago, I tried to do something similar with another
> compiler. I tried to statically initialize a big array of chars.
> In practice I wrote a program that given a file will create a source *.c
> that statically initialize an array with the data of the file.
> However this approach failed on larger dataset, due to some limitation of
> the compiler.
> I wonder if djgpp, with its lovely flat model,\r has limitations of this kind.
> 
> Another approach that  I'm considering is to append physically the data file at
> the end of  the executable and then finding a way to access it directly,
> but I do not know if in that case the data will be automatically loaded
> somewhere in the memory (where !?) or if I must read it from the disk
> peeking toward the end of the "extended" executable file.
> 
> Suggestions are all wellcome. I'm quite a good C programmer but also quite new
> to djgpp and absolutely ignorant about my 586 asm.

You could define a large char array called x in assembler like this :

..globl  _x
..data
_x:
          .byte 1,2,3,4
          .byte 5,6,7,8

          etc.

(you can put more bytes per line if you want)

This is then assembled with a command line like

as z.s -o z.o

Your C program would then have a declaration like

extern char x[];


and you would link the file z.o with your C.

I just tried this and produced a 300k array very easily.

--
Martin