Re: Linux kernel crash dumps for ARM

[ebiederm@xmission.com (Eric W. Biederman)]

Venkappa Mala <Venkappa.Mala@lntinfotech.com> writes:

I have added the kexec list and corrected the lkml addresses.
In principle it should not be too hard to use kexec on panic
support on arm.

I don't do any arm development so I don't have a clue what the status
of the support is on arm.

> Hi,
>
> With respect to "Linux kernel crash dumps for ARM", i have some doubts which are described as below.
>
> If the machine has crashed so badly that you cannot enter commands or
> the disk is not available then you have three options :-
>
> (1) Hand copy the text from the screen
>
> (2) capture crash logs using Minicom.
>
> (3) save the crash data to a floppy disk or video rom or a swap partition or reserved memory.
>
> In the above three options, 1 & 2 are known and works as well.
>
> Regarding 3 option,
> ----------------------------
> i would like to support for ARM11.
>
> As far as i know, the supported linux kernel crash dumps are
> "lkcd, netdump,diskdump, mini kernel dump and kdump/kexec".
> These are supported for x86 and PowerPC architectures with some constrains.
>
> i have some queries with respect to ARM supports, these are
>
> 1.) kexec is supported in latest kernels
>         example: 2.6.29 kernel
>         File: arch/arm/kernel/machine_kexec.c
>
>     - is this working well or is there any constraints?
>
> 2) As per kexec supports, kexec-tool is required and this allows you to load directly
>    to a new kernel from the currently running one
>
>     As from my side, i am not able to find arm implementation support in kexec-tools/crash sources.
>
>    - is kexce-tool supported for ARM or not?
>
> 3) In lkcd, netdump,diskdump, mini kernel dump and kdump/kexec tools,
>
>    - which is the best choice for ARM or are there any best crash dump tool for ARM?
>
> Please clarify my queries.
>
> Best Regards,
> Venkappa

Eric