[ECOS] RE: eCos ARM7TDMI porting

Patrick Doyle wpd@delcomsys.com
Wed Nov 13 08:50:00 GMT 2002

> -----Original Message-----
> From: AL Chane [mailto:al_chane@issc.com.tw]
> Sent: Tuesday, November 12, 2002 6:04 PM
> To: wpd@delcomsys.com
> Subject: eCos ARM7TDMI porting
> Hi,
>      I got your e-mail from eCos discussion group. I
> am doing an eCos ARM7TDMI port, wondering if I can
> get any help/suggestion from you.
I'll do what I can, but you will get much better help, from more experienced
folks than I, if you post your request to the eCos discussion group at
large.  I have forwarded this to the group.

>      The board I have is Samsung 44B0 with core ARM7TDMI.
> I use the existing E7T board (Samsung 4510 with core ARM7TDMI) as
> a template
> to
> modify for the 44B0 board. I pretty much followed the porting
> instruction at
> http://sources.redhat.com/ecos/docs-latest/porting/hal-plf-process.html
> After building a basic GDB stub, I use 44B0 board's monitor program
> to download stub and run it. The monitor program shows
> "undefined instruction exception". For me it seems like it doesn't
> recognize the built image (stub). I also tried to use "objcopy" to
> convert .img to .bin. Got same result.
Well, I don't know anything at all about the 44B0 board, nor what monitor
program might be on it, but some issues to consider are:

1) What format does the monitor expect for downloading files?  ELF, SREC,
raw binary?  I'm afraid I can't answer that question for you, but once you
know what format it expects, you should be able to use objcopy to produce
the correct format.  Unless, it expects some sort of proprietary format, in
which case you might be better off writing your own utility program that
converts between S-records (easiest), elf, or binary to the proprietary

2) What is the memory map of the board?  Where is ROM (FLASH)?  Where is
RAM?  How much of each?  Again, I can't answer these questions, but your
build image should probably be built to run in RAM.

3) How are interrupts handled?  If you are just trying to download stubs,
this doesn't matter too much, since no interrupts are used, but eventually
you will need to answer this.

> Do you have any idea what might be wrong? Any porting experience
> can share with me?
> thanks for the helps.
> best regards,
> Al Chane
I'm sure there are a lot of other questions that could be asked.  But that's
where I would start.


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