issues with wic creating "multi-partition" images?

issues with wic creating "multi-partition" images?

[Robert P. J. Day]

  asking from a position of massive ignorance since i just started
digging into wic, but i've been reliably assured that i am going to
encounter issues with trying to get wic to create what i choose to
call "multi-partition" images, and i just want to know if this is an
actual issue.

  current wic setup is to create an image which supports what i'll
call the "preserve" partition -- distinct partition to hold
non-upgradeable content; factory default firmware, non-volatile S/W
config settings, that sort of thing, that is meant to be preserved
across software upgrades. nothing unusual about this, strikes me as
pretty standard.

  now, any recipe in the current build is allowed to contribute its
own preserve data by adding it to a top-level "/preserve" directory.
that directory is added to the content of the base package:

  FILES_${PN} += "/preserve"

and in the end, the wic image is responsible for taking everything
under /preserve in the final rootfs and installing it in the preserve
partition, wholly separate from however it installs the remainder of
the rootfs.

  does wic have a problem with doing this? it seems so straightforward
that i'm having trouble believing wic can't do it. thoughts? or
perhaps a link to some reference board or vendor that has a .wks file
that does exactly that?

rday

p.s. there is no separate wic mailing list is there?

Re: [OE-core] issues with wic creating "multi-partition" images?

[Alexandre Belloni]

Hello,

On 12/08/2021 05:26:47-0400, Robert P. J. Day wrote:
> 
>   asking from a position of massive ignorance since i just started
> digging into wic, but i've been reliably assured that i am going to
> encounter issues with trying to get wic to create what i choose to
> call "multi-partition" images, and i just want to know if this is an
> actual issue.
> 
>   current wic setup is to create an image which supports what i'll
> call the "preserve" partition -- distinct partition to hold
> non-upgradeable content; factory default firmware, non-volatile S/W
> config settings, that sort of thing, that is meant to be preserved
> across software upgrades. nothing unusual about this, strikes me as
> pretty standard.
> 
>   now, any recipe in the current build is allowed to contribute its
> own preserve data by adding it to a top-level "/preserve" directory.
> that directory is added to the content of the base package:
> 
>   FILES_${PN} += "/preserve"
> 
> and in the end, the wic image is responsible for taking everything
> under /preserve in the final rootfs and installing it in the preserve
> partition, wholly separate from however it installs the remainder of
> the rootfs.
> 
>   does wic have a problem with doing this? it seems so straightforward
> that i'm having trouble believing wic can't do it. thoughts? or
> perhaps a link to some reference board or vendor that has a .wks file
> that does exactly that?

In your wks.in, you can simply do something like that:

part / --source rootfs --fstype=ext4 --label root --exclude-path=preserve/
part /preserve --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/preserve --fstype=ext4 --label preserve


-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [OE-core] issues with wic creating "multi-partition" images?

[Robert P. J. Day]

On Thu, 12 Aug 2021, Alexandre Belloni wrote:

> Hello,
>
> On 12/08/2021 05:26:47-0400, Robert P. J. Day wrote:
> >
> >   asking from a position of massive ignorance since i just started
> > digging into wic, but i've been reliably assured that i am going to
> > encounter issues with trying to get wic to create what i choose to
> > call "multi-partition" images, and i just want to know if this is an
> > actual issue.
> >
> >   current wic setup is to create an image which supports what i'll
> > call the "preserve" partition -- distinct partition to hold
> > non-upgradeable content; factory default firmware, non-volatile S/W
> > config settings, that sort of thing, that is meant to be preserved
> > across software upgrades. nothing unusual about this, strikes me as
> > pretty standard.
> >
> >   now, any recipe in the current build is allowed to contribute its
> > own preserve data by adding it to a top-level "/preserve" directory.
> > that directory is added to the content of the base package:
> >
> >   FILES_${PN} += "/preserve"
> >
> > and in the end, the wic image is responsible for taking everything
> > under /preserve in the final rootfs and installing it in the preserve
> > partition, wholly separate from however it installs the remainder of
> > the rootfs.
> >
> >   does wic have a problem with doing this? it seems so straightforward
> > that i'm having trouble believing wic can't do it. thoughts? or
> > perhaps a link to some reference board or vendor that has a .wks file
> > that does exactly that?
>
> In your wks.in, you can simply do something like that:
>
> part / --source rootfs --fstype=ext4 --label root --exclude-path=preserve/
> part /preserve --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/preserve --fstype=ext4 --label preserve

  that's what i thought, so i'm going back to the current setup to try
to figure out what the originators thought the problem was.

rday

p.s. as i read it, the only distinction between a "wks" and a "wks.in"
file is the need to pre-process variable substitution in the latter,
correct?

Re: [OE-core] issues with wic creating "multi-partition" images?

[Alexandre Belloni]

On 12/08/2021 05:50:53-0400, Robert P. J. Day wrote:
> p.s. as i read it, the only distinction between a "wks" and a "wks.in"
> file is the need to pre-process variable substitution in the latter,
> correct?

It is my understanding, yes.

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com