Issues with the system startup when the IMAGE_TYPE is squashfs

Issues with the system startup when the IMAGE_TYPE is squashfs

[Christian Pössinger]

Hello,

I'm currently building a rootfs that will be stored in a squashfs
container. The file is properly created by OpenEmbedded, but I noticed
some issues:

First of all, when I boot an OE generated rootfs for the first time, a
file called /etc/volatile.cache will be generated. As of the fact that
squashfs is read-only this file can't be created.

The second issue comes with the kernel modules. Again, the first system
startup will create the modules.dep file inside the /lib/modules/$(uname
-a) directory. But as stated before, this is not possible on a read-only
filesystem.

Is there any way within OpenEmbedded to create those files before the
actual rootfs image is packed?


Best regards,

Christian Pössinger
Software Development

Mixed Mode GmbH
Lochhamer Schlag 17
D-82166 Gräfelfing/München
Tel.        +49 / 89 / 89 86 8-200
Fax        +49 / 89 / 89 86 8-222
Mobil        +49 / 172 /
http://www.mixed-mode.de

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Thomas Kunze]

Christian Pössinger schrieb:
> Hello,
>
> I'm currently building a rootfs that will be stored in a squashfs
> container. The file is properly created by OpenEmbedded, but I noticed
> some issues:
>
> First of all, when I boot an OE generated rootfs for the first time, a
> file called /etc/volatile.cache will be generated. As of the fact that
> squashfs is read-only this file can't be created.
>
> The second issue comes with the kernel modules. Again, the first system
> startup will create the modules.dep file inside the /lib/modules/$(uname
> -a) directory. But as stated before, this is not possible on a read-only
> filesystem.
>
>   
I did this some time ago: http://bugs.openembedded.net/show_bug.cgi?id=3714
I guess you can do something like this with /etc/volatile.cache too.
> Is there any way within OpenEmbedded to create those files before the
> actual rootfs image is packed?
>
>
> Best regards,
>
> Christian Pössinger
> Software Development
>
> Mixed Mode GmbH
> Lochhamer Schlag 17
> D-82166 Gräfelfing/München
> Tel.        +49 / 89 / 89 86 8-200
> Fax        +49 / 89 / 89 86 8-222
> Mobil        +49 / 172 /
> http://www.mixed-mode.de
>
>
>
>
> _______________________________________________
> Openembedded-devel mailing list
> Openembedded-devel@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel
>   

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Otavio Salvador]

Thomas Kunze <thommycheck@gmx.de> writes:

> I did this some time ago: http://bugs.openembedded.net/show_bug.cgi?id=3714
> I guess you can do something like this with /etc/volatile.cache too.

Are you interested in making the changes that were suggest in the bug
report to allow us to merge it?

 - move it to update-modules-cross
 - make it a distro option; not a requirement

-- 
        O T A V I O    S A L V A D O R
---------------------------------------------
 E-mail: otavio@debian.org      UIN: 5906116
 GNU/Linux User: 239058     GPG ID: 49A5F855
 Home Page: http://otavio.ossystems.com.br
---------------------------------------------
"Microsoft sells you Windows ... Linux gives
 you the whole house."

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Thomas Kunze]

Otavio Salvador schrieb:
> Thomas Kunze <thommycheck@gmx.de> writes:
>
>   
>> I did this some time ago: http://bugs.openembedded.net/show_bug.cgi?id=3714
>> I guess you can do something like this with /etc/volatile.cache too.
>>     
>
>   
I don't have time for working on OE atm.
> Are you interested in making the changes that were suggest in the bug
> report to allow us to merge it?
>
>  - move it to update-modules-cross
>   
This is just a simple rename.
>  - make it a distro option; not a requirement
>
>   
I don't agree with that. It really don't see how this patch could break 
images. If it works I see no reason why any distro doesn't want to have 
this.

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Otavio Salvador]

Thomas Kunze <thommycheck@gmx.de> writes:

> This is just a simple rename.
>>  - make it a distro option; not a requirement
>>
>>   
> I don't agree with that. It really don't see how this patch could
> break images. If it works I see no reason why any distro doesn't want
> to have this.

This is a behaviour change and before making it a requirement it needs
to be tested.

Personally I also see no reason for it to break images but it is
always better be safe then sorry.

-- 
        O T A V I O    S A L V A D O R
---------------------------------------------
 E-mail: otavio@debian.org      UIN: 5906116
 GNU/Linux User: 239058     GPG ID: 49A5F855
 Home Page: http://otavio.ossystems.com.br
---------------------------------------------
"Microsoft sells you Windows ... Linux gives
 you the whole house."

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Christian Pössinger]

On Do, 13.11.2008, 21:22, Otavio Salvador wrote:
> This is a behaviour change and before making it a requirement it needs
> to be tested.
>
> Personally I also see no reason for it to break images but it is
> always better be safe then sorry.

I tested the patch and it worked quiet well for me on the stable tree.
Seeing this build into OpenEmbedded would be great.


Best regards,
Christian

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Marcin Juszkiewicz]

Thursday 13 of November 2008 12:19:28 Christian Pössinger napisał(a):
> I'm currently building a rootfs that will be stored in a squashfs
> container. The file is properly created by OpenEmbedded, but I
> noticed some issues:

> The second issue comes with the kernel modules. Again, the first
> system startup will create the modules.dep file inside the
> /lib/modules/$(uname -a) directory. But as stated before, this is not
> possible on a read-only filesystem.
>
> Is there any way within OpenEmbedded to create those files before the
> actual rootfs image is packed?

Each kernel module has postinstall script (added by kernel.bbclass) 
which calls 'depmod -a' and update-modules. Opkg intercepts depmod calls 
to make it just one call in 'opkg configure' during first boot. In 
effect your rootfs has all module dependencies generated on build time. 
You can probably remove second part of those postinstalls to not call 
them on device at all.

Regards, 
-- 
JID:      hrw@jabber.org
Website:  http://blog.haerwu.biz/
LinkedIn: http://www.linkedin.com/in/marcinjuszkiewicz

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Tom Rini]

On Mon, Nov 17, 2008 at 05:31:24PM +0100, Marcin Juszkiewicz wrote:
> Thursday 13 of November 2008 12:19:28 Christian Pössinger napisa??(a):
> > I'm currently building a rootfs that will be stored in a squashfs
> > container. The file is properly created by OpenEmbedded, but I
> > noticed some issues:
> 
> > The second issue comes with the kernel modules. Again, the first
> > system startup will create the modules.dep file inside the
> > /lib/modules/$(uname -a) directory. But as stated before, this is not
> > possible on a read-only filesystem.
> >
> > Is there any way within OpenEmbedded to create those files before the
> > actual rootfs image is packed?
> 
> Each kernel module has postinstall script (added by kernel.bbclass) 
> which calls 'depmod -a' and update-modules. Opkg intercepts depmod calls 
> to make it just one call in 'opkg configure' during first boot. In 
> effect your rootfs has all module dependencies generated on build time. 
> You can probably remove second part of those postinstalls to not call 
> them on device at all.

Another option, if your kernel only builds the modules you want to
install, is have module.dep, etc, be built in the install section of the
kernel recipe and package them up into the kernel-modules package.  The
only slight trick is that you need to do this in kernel_do_install in
kernel.bbclass:
oe_runmake DEPMOD=`which ${TARGET_PREFIX}depmod-2.6` INSTALL_MOD_PATH="${D}" modules_install
Since the kernel does some tests which mean that DEPMOD must be passed
as a full path.

-- 
Tom Rini

Re: Issues with the system startup when the IMAGE_TYPE is squashfs

[Koen Kooi]

On 17-11-08 17:31, Marcin Juszkiewicz wrote:

> Each kernel module has postinstall script (added by kernel.bbclass)
> which calls 'depmod -a' and update-modules. Opkg intercepts depmod calls
> to make it just one call in 'opkg configure' during first boot.

I doesn't. Opkg doesn't ship the intercept scripts anymore.

regards,

Koen