delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1997/11/11/01:49:30

Date: Tue, 11 Nov 1997 19:48:38 +1100
From: Bill Currie <billc AT blackmagic DOT tait DOT co DOT nz>
Subject: Re: NS486SXF development
In-reply-to: <199711110614.OAA15157@public.bta.net.cn>
To: tanph AT bj DOT col DOT com DOT cn, djgpp AT delorie DOT com
Message-id: <199711110645.TAA20796@teleng1.tait.co.nz gatekeeper.tait.co.nz>
Organization: Tait Electronics Limited
MIME-version: 1.0
Comments: Authenticated sender is <billc AT blackmagic DOT tait DOT co DOT nz>

On 11 Nov 97 at 14:11, tanph AT bj DOT col DOT com DOT cn wrote:

> Hello, DJGPP gurus,
> 
> I have a project to develop software for NS486SXF.  NS486SXF is
> National Semiconductor's embedded 486 CPU, it is different from
> Intel 486 in that it only has protected mode and doesn't have memory
> paging mechanism. 

Interesting configuration.


> DJGPP is a marvelous programming environment, and I'd like to use it
> to do embedded NS486SXF  software programming if possible. But I
> find it difficult to use DJGPP this way.
> 
> (1) The target is only a bare CPU, we don't have and aren't willing
> to have any OS running on it, so I must find a way to convert
> DJGPP-produced program to pure binary format and put it into a
> bootable ROM.

You might find my kernel source a help in how to use djgpp to build 
a standalone os. It's located et 
http://www.abwillms.demon.co.uk/prog/kernel2.zip (look at 
http://www.abwillms.demon.co.uk/prog/index.htm at the bottom for more 
info).

 
> (2) How to debug the program under this circumstance, how to modify
> GDB or FSDB in order to run it on a bare CPU?

Ouch. gdb has provisions for debugging over a serial line 
(my kernel happens to have serial support), but I believe you will 
have to hack in the serial support on the pc side, though I seem to 
remember someone already doing this.

As to fsdb, I have no idea how to do it, but of course it is 
possible (anything is possible in software, just some things are 
very hard).

> 
> Any suggestions are appreciated.


I hope this helps.  Unfortunatly, I'm leaving the net after thursday 
(nz time) as I'm changing jobs, and I don't know how long it will be 
until I get a new email address. So, any questions: ask them fast :)

Bill
--
Leave others their otherness.

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019