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Re: Redboot : Do ping from host to target does not work !
- From: Jonathan Larmour <jifl at jifvik dot org>
- To: Hurstel Jérôme <jerome dot hurstel at orange-ftgroup dot com>
- Cc: eCos discussion <ecos-discuss at ecos dot sourceware dot org>
- Date: Thu, 24 Sep 2009 17:19:09 +0100
- Subject: Re: [ECOS] Redboot : Do ping from host to target does not work !
- References: <200909241714.15075.jerome.hurstel@orange-ftgroup.com>
Hurstel Jérôme wrote:
I want to do remote debugging with GDB. At this point, I have built Redboot
and it starts well and get an IP address from my bootp server. I am also able
to ping my host from Redboot prompt.
Nevertheless, I can't do the opposite : Redboot does not answer to ping
initiated from my host ! However I can tell that ICMP ping request frames are
well received by my ethernet device (LAN91CXX). But as interrupts are not
globally enabled in ARM CPSR register, Redboot does not know anything about
them !
Redboot operates with interrupts off. This was an intentional design
decision (otherwise redboot might have to deal with all sorts of
unexpected interrupts, which should really be for an application to deal
with).
Does Redboot install a listener which poll on ethernet interface ? And where
is it done in source code ?
Yes it does poll, and doesn't use interrupts. See redboot's net_io.c,
that's the place to start if you want to understand it.
If I remember right, RedBoot did at one point have a flaw (perhaps it
still does?) where if you typed in something on e.g. the serial console
_and_didn't_press_return_, it would not poll the network code, and thus
not notice pings. Worth checking.
Is it possible to enable interrupts in CPSR ? And where is the best place to
do it ?
Enabling interrupts won't be the solution here.
Clearly if you can ping from redboot, redboot _can_ both send and receive
packets. I assume you have no firewall in the way. You may also want to
double-check what you see with a packet sniffer.
Jifl
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