Date: Tue, 11 Nov 1997 19:48:38 +1100 From: Bill Currie 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 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Comments: Authenticated sender is Precedence: bulk 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.