From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Philipp Ittershagen <lists@gate-nine.de>
Cc: linuxppc-dev@lists.ozlabs.org, Guillaume Dargaud <dargaud@lpsc.in2p3.fr>
Subject: Re: Early kernel debugging
Date: Mon, 28 Mar 2011 10:25:16 +1100 [thread overview]
Message-ID: <1301268316.2402.489.camel@pasglop> (raw)
In-Reply-To: <4D8F7B55.2050806@gate-nine.de>
On Sun, 2011-03-27 at 20:00 +0200, Philipp Ittershagen wrote:
> On 03/25/2011 09:50 AM, Guillaume Dargaud wrote:
> > Hello all,
> > what can you do when the kernel you try to run stops before printing anything on the console ?
>
> http://elinux.org/Kernel_Debugging_Tips#Debugging_early_boot_problems
>
> Basically it means connecting a debugger to the running kernel (using
> XMD, for example) and then reading the printk log buffer, which contains
> the last lines printed.
It actually mostly depends on the platform. There's various powerpc
specific early debug mechanisms that are more/less robust/functional
depending on the CPU type, the platform, etc...
Look in udbg.c, there's a list of early debug hacks in there controlled
by various config options.
Cheers,
Ben.
next prev parent reply other threads:[~2011-03-27 23:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-25 8:50 Early kernel debugging Guillaume Dargaud
2011-03-27 18:00 ` Philipp Ittershagen
2011-03-27 23:25 ` Benjamin Herrenschmidt [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-04-02 20:05 early " Yigal Goldberger
2009-04-03 16:04 ` Tirumala Reddy Marri
2009-04-03 16:47 ` Feng Kan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1301268316.2402.489.camel@pasglop \
--to=benh@kernel.crashing.org \
--cc=dargaud@lpsc.in2p3.fr \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=lists@gate-nine.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.