kgdb with 2.4.20pre7 kernel on 405 target

kgdb with 2.4.20pre7 kernel on 405 target

[Matthias Fuchs]

Hi,

I am trying to use a cross gdb against a 405 target (CPCI405) using a kgdb kernel
on the target. The kernel is exported from bitkeeper this morning.
The host gdb for 405 is version 5.1.1 from the Denx ELDK.

When I boot my target, it stops and waits for the gdb connection. Then
I start ppc_4xx-gdb on my x86 host with vmlinux as argument.

I enter "target remote /dev/ttyS1" at the gdb prompt and get:

Remote debugging using /dev/ttyS0
0xc000d77c in breakinst ()
(gdb)

I thinks that's fine so far. Then I type "c" and my target keeps on booting. My gdb says:

(gdb) c
Continuing.
Can't send signals to this remote system.  SIGILL not sent.

What does this mean ? From now on I cannot interupt the target.

Is this a problem with kgdb ?

Matthias


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Re: kgdb with 2.4.20pre7 kernel on 405 target

[Matt Porter]

On Tue, Sep 17, 2002 at 11:35:18AM +0200, Matthias Fuchs wrote:
> on the target. The kernel is exported from bitkeeper this morning.

<snip>

> What does this mean ? From now on I cannot interupt the target.
>
> Is this a problem with kgdb ?

In 2_4_devel, the 4xx debug infrastructure is in the middle of a
change which moves DBCR state from pt_regs to thread struct.
Without DBCR being context switched, anything using the 4xx
debug exception will be adversely affected.  This includes
kgdb and ptrace.

Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

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Re: kgdb with 2.4.20pre7 kernel on 405 target

[Michel Normand]

By looking at the history of kgdb problem on 405,  we found the two
following messages
related to kgdb failure on 405 target, messages dated from September 2002:
http://lists.linuxppc.org/linuxppc-embedded/200209/msg00166.html
http://lists.linuxppc.org/linuxppc-embedded/200209/msg00170.html

Is there now  in 2.4.20 kernel a patch to solve this problem ?

>
>  In 2_4_devel, the 4xx debug infrastructure is in the middle of a
> change which moves DBCR state from pt_regs to thread struct.
> Without DBCR being context switched, anything using the 4xx
> debug exception will be adversely affected. This includes
> kgdb and ptrace.
>
>Regards,
> --
>Matt Porter
>porter@cox.net

----
Michel
Internet addr:  normand@fr.ibm.com


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