This is the mail archive of the
ecos-discuss@sources.redhat.com
mailing list for the eCos project.
Re: RedBoot+GDB+application combo question
- From: Savin Zlobec <savin dot zlobec at email dot si>
- To: Stephan Eisvogel <eisvogsn at iis dot fhg dot de>
- Cc: ecos-discuss at sources dot redhat dot com
- Date: Sat, 21 Feb 2004 20:07:45 +0100
- Subject: [ECOS] Re: RedBoot+GDB+application combo question
- References: <20040220190214.C40808B746@www.email.si> <40366376.A0F782C8@iis.fhg.de>
On Fri, 20 Feb 2004 at 20:43:49, Stephan Eisvogel wrote:
> Savin Zlobec wrote:
> > Is there any reason why 'dbtrap' instruction can't be used for breakpoints ?
>
> It is a 32-bit instruction, which would mean that by putting a break on
> the first of two successive 16-bit instructions, the second would get
> corrupted by that dbtrap's second 16 bits. If this is the only BP, you
> could envision a case where -provided you take no overly excessive read
> impossible precautions during runtime- a jump from anywhere could target
> this second, now temporarily overwritten, instruction. Oops...
>
> I did a lot of research for this processor looking for ways to make GDB
> debugging possible, "br *" and a periodic (10-30 Hz) NMI pulse were the
> only option I could come up with that looked promising. Since we do many
> many designs for this processor still, we at least have the hardware to
> debug this kind of stuff.
I'am aware of 16/32 bit gdb breakpoint instruction thing - it is just that
I somehow remember the 'dbtrap' as a 16 bit instruction (have to check that
in the docs).
savin
____________________
http://www.email.si/
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss