Writeable /etc

[antonlacon]

This makes /etc/ writeable via an overlayfs backed by /storage. I'm using it in testing other things (users/groups), but given the number of symbolic links coming out of /etc to /storage or /var, I'm sharing it.

Labeled WIP because although it's functionally complete, storage-dirs.service should probably be replaced by tempfiles.d usage. Maybe move the systemd files from busybox to systemd's package too. Busybox's package was picked because it has the var.mount file too.

Blocked for discussion.

[antonlacon]

Replaced storage-dirs.service with a tmpfiles.d method. I'm not aware of how the numbering/naming of the tmpfiles.d files works, so I picked early, but not first.

[kszaq]

I am using LibreELEC for non-mediacenter purposes and need a writeable rootfs.

I created /flash/mount-storage.sh script that mounts overlayfs:

mount_part "$disk" "/storage" "rw,noatime"

/sysroot/usr/bin/insmod /sysroot/usr/lib/kernel-overlays/base/lib/modules/$(uname -r)/kernel/fs/overlayfs/overlay.ko

/usr/bin/busybox mkdir -p /dev/rom
mount --move /sysroot /dev/rom

/usr/bin/busybox mkdir -p /storage/.overlay/upper
/usr/bin/busybox mkdir -p /storage/.overlay/work
mount -t overlay overlay -o lowerdir=/dev/rom,upperdir=/storage/.overlay/upper,workdir=/storage/.overlay/work /sysroot

For devices booting from SD card the advantage is that if I mess something up, I can simply take out the SD card and remove this file to not mount overlay on next boot.

[antonlacon]

I did something similar in busybox's init: ffc98ee It was turned on/off by adding/removing 'rootoverlay' to the kernel's command line. It's been several years since I used it so no idea if it applies cleanly.