This is the mail archive of the
ecos-discuss@sources.redhat.com
mailing list for the eCos project.
Re: bootloader into the gdb_module stabs
- To: Hansjörg Petriffer <hpetriffer at grips dot com>
- Subject: Re: [ECOS] bootloader into the gdb_module stabs
- From: Jonathan Larmour <jlarmour at redhat dot com>
- Date: Tue, 27 Mar 2001 16:04:15 +0100
- Cc: "Ecos-Discuss (E-Mail)" <ecos-discuss at sourceware dot cygnus dot com>
- Organization: Red Hat UK Ltd.
- References: <C05DB78BB4E1D411B6C100508BF7DCD5327319@GRIPS_NTS2>
Hansjörg Petriffer wrote:
>
> Hello
>
> I'm searching at the moment the part with the bootloader which loads the
> programm over the serial connection. But my problem is that I can't find the
> part that does that. I have found the cyg_start, which I think is the entry
> point, but I'm not sure how it works. Could anyone help me? Is there any
> description available for that part, where I can find? I need that, because
> I will test a few things with a own bootloader.
>
> Thanks for any hint!
In general, the program in the stub image deliberately hits a breakpoint
instruction (see hal/common/current/src/stubrom/stubrom.c for an example).
This causes an exception. eCos arranged for the built-in GDB stubs to
handle the exception that was generated, so that causes the stub code to be
entered. The stub then listens on the serial line for communication with
GDB (including, for example, memory write commands that will cause the
program to be loaded).
Jifl
--
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine