[OE-core] [PATCH] image_types: Ensure /init exists for cpio rootfs archives

[Andrea Adami]

On Wed, Jan 11, 2012 at 12:07 AM, Andrea Adami <andrea.adami at gmail.com> wrote:
> On Fri, Jan 6, 2012 at 11:58 PM, Andrea Adami <andrea.adami at gmail.com> wrote:
>> On Fri, Jan 6, 2012 at 11:57 AM, Richard Purdie
>> <richard.purdie at linuxfoundation.org> wrote:
>>> On Fri, 2012-01-06 at 02:00 +0100, Andrea Adami wrote:
>>>> On Fri, Jan 6, 2012 at 12:36 AM, Darren Hart <dvhart at linux.intel.com> wrote:
>>>> >
>>>> >
>>>> > On 01/05/2012 04:30 AM, Richard Purdie wrote:
>>>> >> On Thu, 2012-01-05 at 01:05 +0100, Andrea Adami wrote:
>>>> >>> I'd say we have to test for the in-existence of the file instead of
>>>> >>> blindly touching it.
>>>> >>> Smthg like
>>>> >>>
>>>> >>> if [! -e ${IMAGE_ROOTFS}/init]; then
>>>> >>> touch ${IMAGE_ROOTFS}/init
>>>> >>> fi
>>>> >
>>>> > Why? Touch creates it if it doesn't exist and updates the modtime if it
>>>> > does. It doesn't modify the content of the file if it exists. What is
>>>> > the motivation for testing for it's existence?
>>>> >
>>>> touch fails with Permission denied because one package in my rootfs
>>>> already created the symlink
>>>>
>>>> >>>
>>>> >>>
>>>> >>> Now, repeating that block for all 4 cpio images is a bit ugly... better ideas?
>>>> >>
>>>> >> Make it a shell function we call? I'd also check for
>>>> >> ${base_sbindir}/init first too?
>>>> >
>>>> > Why check for that? So we can link to it instead of creating an empty file?
>>>>
>>>> Nonsense, kernel looks for /init
>>>> ( http://www.kernel.org/doc/Documentation/filesystems/ramfs-rootfs-initramfs.txt
>>>> )
>>>
>>> Yes, please ignore my comment about /sbin/init, I'm misremembering
>>> something. We should deal with the symlink case though.
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>>>
>>> _______________________________________________
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>>> Openembedded-core at lists.openembedded.org
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>>
>> ok, I think the issue is the behavior of touch when trying to change
>> the timestamp of a symlink.
>>
>> http://fossplanet.com/f13/bug-7122-touch-gnu-coreutils-7-4-no-way-touch-symlink-57418/
>>
>> Using 'touch -h' seems solving the issue and the image is built.
>> However, the timestamp of the /init symlink now differs from the
>> timestamp of the binary.
>>
>> Regards
>>
>> Andrea
>
>
> Ok, now I think I understand the issue:
>
> the /init symlink in rootfs is absolute, being its path is pointing to
> /usr/bin/kexecboot in our case.
> Now, until this becomes the real rootfs, the symlink appears broken
> and that's why adding the -h (do not dereference) fixes the case of
> existent symlink.
>
> Unfortunately it appears touch -h fails if /init is a file and not a
> symlink (tested now).

This must have been an error on my side mixing previous builds.
No errors using touch -h on files.

Sorry for the confusion

>
> Afterall, I think it would be easier to add a guard around touch as
> initially proposed.
>
> Just my 2 cents
>
 Andrea