as I did not have much success with my question in the OR irc, let's try it here in a more verbose way. ;)
Imagine I have an A+B redundant boot system, with additional bootloader and separate home or application file system. Thus my layout would be like:
p1: bootloader p2: rootfs A p3: rootfs B p4: appfs A p5: appfs B
where rootfs A + appfs A form a logical unit with respect to the image- based update handling.
No my question is: How do I generate the images required for the bootloader partition and/or the appfs partition with the OE standard image generation mechanisms?
We have a working solution with the 'genimage' tool for quite some time, but I wonder if that could be done with the more tightly integrated wic, too.
To my understanding, the way of creating something like a bootloader image or an application file system is by using wic's image split capabilities and doing (non-redundant example):
part /boot --source rootfs (or some plugin) part / ... --source rootfs part /app --source rootfs
I had the same use case as you, and I could use something like part /app --source rawcopy --sourceparams="file=..." and the file points to the image I want to put on the partition.
This will create multiple file system images out of the prior monolitic rootfs one. It also does all necessary changes for mounting, like modifying the rootfs /etc/fstab etc. Thus, using these generated images in my update scenario would be the way to go for me.
BUT, currently I do not see any straight-forward way of how to use them. One could add them to what the image_wic* image fstypes generate, but this will violate the default rule that each image fstype generates exactly one image. And the generated images are a little hard to reference as one cannot give them names (which is probably a negligable issue) and they do not have a fstype extension. The more sever issue is that I would also like to have archives (like tar.bz2) of the content of /app or /boot as I can use them quite good for installing to partitions whose size and other parameters I do not know very beforehand (also applicable to UBI volumes).
But, at the moment there does not seem to be a designated way of doing something like I intended. I wonder how others solve the generation of non-rootfs images with YP/OE?
Or did I miss something that already exists for this?
I have not a straightforward solution. I inherited just "image" and I cleaned up at the end with a ROOTFS_POSTPROCESS_COMMAND what was superfluous. Maybe forcing packagegroup-core-boot can be an option.
Yeah, this is also what I often end up doing. I often need a way to bundle several artifacts together, i.e. bootloader, rootfs, sdk, etc.
With that in mind, I would also very much like a way to make image artifacts available in WORKDIR without pulling from DEPLOY_DIR_IMAGE - it just feels wrong to use files from the output folder as input in recipe.
