[XA2 Plus] overlayFS support missing in the kernel [XA2] [SailfishX]

Note that, on the XA2, modules are not disabled. So until Jolla does this, it is possible to compile your own modules.

Also another added benefit :

• XA2 has containers available in the kernel (well obvious as that's what the new LXC-based Alien Dalvik relies on)

• if somebody adds OverlayFS, it becomes possible to run docker without needing to reformated BTRFS partitions.

Note that, on the XA2, modules are not disabled. So until Jolla does this, it is possible to compile your own modules.

Good point. TBH, I just shy away from the effort of finding the right kernel version, the right tool chain, etc. :) So if Jolla did it, it would be way more convenient. But yes, that's the coolness about FOSS: If the vendor doesn't help you, you can help yourself ;).

On the smartphone, uname -a telle me:

Linux Sailfish 4.4.172 #1 SMP PREEMPT Wed Feb 13 06:03:28 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux

Which you can easily retrieve from the official kernel.org repository (it's not that much outdated, actually) (And I doube any extra patches from Qualcomm, Sony or Jolla would influence the drivers we're interested in).

The current configuration of the kernel can be found on the phone inside /proc/config.gz

For the tool chain we've got several alternatives :

• installing gcc & make on the smartphone itself with zypper (or pkcon)
• official Sailfish SDK
• CODeRUS docker container
• SailfishOS' Open Build Service (formerly known as Mer's OBS)

Now what remains to be done:

• find the correct list of arcane commands needed to get ONLY the desired module to compile and not the whole shebang... (My kernel-fu is a bit rusty, but there's a sequence of specific targets like make kerlenversion scripts prepare etc. that would only compile the desired parts instead of make all)
  • Pointer at Askubunut
  • Pointer at Stackoverflow
• for the specific case of making RPMs (e.g. using the OBS service), wrap then the instructions into a SPEC file and build the RPM itself.

It this last part that is going to take an afternoon of hacking.