KEXEC on ARM Cortex-A15 versatile express V2P

[Naresh Bhat]

Hi Daniel,

I have also tried enabling the DEVICETREE option but no luck on latest
3.7 kernel.

root at arm-cortex-a15:~# kexec -l zImage --command-line="console=ttyAMA0,38400n8"
Modified cmdline:console=ttyAMA0,38400n8 root=/dev/nfs
Unable to find /proc/device-tree//chosen/linux,stdout-path, printing
from purgatory is diabled
root at arm-cortex-a15:~# kexec -e
Uncompressing Linux...

I have a question is it required to enable "LIBFDT" option ?  I have
used vexpress_defconfig file in which it is not enabled.

Symbol: LIBFDT [=n]
Type  : boolean


Thanks and Regards
-Naresh Bhat

On Wed, Jan 2, 2013 at 7:26 PM, Naresh Bhat <nareshgbhat at gmail.com> wrote:
> Hi Daniel Mack,
>
> I have tried with the latest kernel and getting the below error
>
> root at arm-cortex-a15:~/3.7-kernel#
> 3.7-kernel# kexec -f zImage --dtb=v.dtb --command-line="console=ttyAMA0,38400n8"
> FDT: Error setting /chosen/bootargs property.
> Cannot load zImage
> root at arm-cortex-a15:~/3.7-kernel#
>
> I will appreciate your inputs
>
> Thanks and Regards
> -Naresh Bhat
>
> On Sat, Dec 15, 2012 at 2:34 AM, Daniel Mack <zonque at gmail.com> wrote:
>> On 14.12.2012 21:58, Daniel Mack wrote:
>>> Hi,
>>>
>>> On 14.12.2012 18:33, Naresh Bhat wrote:
>>>> Thanks for the suggestions.  I really appreciate your help.
>>>>
>>>> I have tried the following in my below setup
>>>
>>> Your should really fix your mailer. The way you quote makes it
>>> impossible to see which lines you added.
>>>
>>>> My setup:
>>>> kexec-tools - latest GIT tree with
>>>> http://lists.infradead.org/pipermail/kexec/2012-December/007526.html
>>>> patch
>>>> Kernel version -   3.4.22
>>>
>>> Why are you running a kernel from the middle ages?
>>>
>>>> Hardware target -  V2P-CA15_A7 Cortex A15 (ARM Versatile Express)
>>>>
>>>> That could be just that the new kernel is missing its bootargs cmdline
>>>> with the appropriate console= tag. How are you booting the first
>>>> kernel?
>>>>
>>>> The first kernel command line console=tty0 console=ttyAMA0,38400n8
>>>> root=/dev/mmcblk0p1 rootwait ro mmci.fmax=6000000
>>>>
>>>> Does you bootloader add a /chosen tag?
>>>>
>>>> I did't understand what you are asking here .  can you please
>>>> elaborate little more ?
>>>
>>> Bootloaders have two ways of passing the command line to the kernel. The
>>> traditional way is to stuff it into a a linked list of boot parameters
>>> (ATAGs), the other is to fill the /chosen/bootargs property in the
>>> device tree and then pass the entire tree.
>>>
>>>> Some suggestions:
>>>>
>>>> 1. Add a static CMDLINE to the second kernel, so it doesn't rely on
>>>> that information being passed from the first on.
>>>>
>>>> root at arm-cortex-a15:~#  kexec -l uImage --dtb=vexpress.dtb
>>>> --command-line="console=tty0 console=ttyAMA0,38400n8
>>>> root=/dev/mmcblk0p1 rootwait ro mmci.fmax=6000000"
>>>> root at arm-cortex-a15:~# kexec -e
>>>> Starting new kernel
>>>> Uncompressing Linux...
>>>
>>> If that doesn't work, your problem is not related to any cmdline issue,
>>> and I might have midlead you here.
>>>
>>> Please try a newer kernel and see if that helps. The kernels I was using
>>> with kexec recently were 3.7-rcX.
>>
>> But just to be clear: it should of course work with the version you're
>> running. So that might not be the reason.
>>
>> And one more thing that might be a hint: check which parts of the
>> hardware are actually running. We experienced some weird lockups during
>> kexec if audio was streaming on our device, but in such cases, we didn't
>> see the "Uncompressing Linux..." output either.
>>
>> Not sure how to help you here really.
>>
>>
>> Daniel
>>
>
>
>
> --
> "For things to change, we must change"
> -Naresh Bhat



-- 
"For things to change, we must change"
-Naresh Bhat