kexec 2.0.4-rc1 won't work on an ARM kernel without device-tree

kexec 2.0.4-rc1 won't work on an ARM kernel without device-tree

[Sven Neumann]

Hi,

I am trying to use kexec-2.0.4-rc1 on an ARM device running Linux 3.0.4.
This old kernel does obviously not have device-tree support. Here's the
error message I get:

# uname -a
Linux speaker 3.0.4 #1 PREEMPT Fri Nov 23 09:15:39 CET 2012 armv5tel GNU/Linux

# kexec --append="console=ttyS0,115200 root=ubi0:RootFS rootfstype=ubifs rw ubi.mtd=3" /boot/uImage --force
unrecoverable error: could not scan "/proc/device-tree/": No such file or directory


Looks like the release candidate depends on the very latest kernel
features and won't work on older kernels? Is that intentional?


Regards,
Sven

-- 
Sven Neumann <s.neumann@raumfeld.com>
Raumfeld by Teufel


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Re: kexec 2.0.4-rc1 won't work on an ARM kernel without device-tree

[Sven Neumann]

Hi,

On Sat, 2012-11-24 at 10:00 +0100, Sven Neumann wrote:

> I am trying to use kexec-2.0.4-rc1 on an ARM device running Linux 3.0.4.
> This old kernel does obviously not have device-tree support. Here's the
> error message I get:
> 
> # uname -a
> Linux speaker 3.0.4 #1 PREEMPT Fri Nov 23 09:15:39 CET 2012 armv5tel GNU/Linux
> 
> # kexec --append="console=ttyS0,115200 root=ubi0:RootFS rootfstype=ubifs rw ubi.mtd=3" /boot/uImage --force
> unrecoverable error: could not scan "/proc/device-tree/": No such file or directory
> 
> 
> Looks like the release candidate depends on the very latest kernel
> features and won't work on older kernels? Is that intentional?

OK, in the meantime I figured out that I can use kexec-2.0.4-rc1 if I
use the --atags command-line parameter. But unless I missed something,
this change in behavior is nowhere documented and thus should be
considered a severe regression. I am somewhat puzzled that no one here
even cared about my email.

IMO the behavior should be changed so that kexec, if called on ARM
without the --dtb or --atags parameters, checks if the running kernel
provides /proc/device-tree. If it doesn't, then this should not be a
fatal error, but it should assume --atags. That would restore the old
behavior for kernels that don't use device-tree.


Regards,
Sven


-- 
Sven Neumann
Head of RAUMFELD Software Development

Lautsprecher Teufel GmbH
Gewerbehof Bülowbogen - Aufgang D1
Bülowstr. 66 - 10783 Berlin - Germany

Registernummer HRB 20271 beim Amtsgericht Berlin-Charlottenburg
Geschäftsführer: Thomas Stiegler, Edgar van Velzen

Tel. +49 (0)30 - 300 930 - 0, Direkt -153
neumann@teufel.de  

www.teufel.de  www.teufelaudio.com  http://blog.teufel.de


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