This patch adds support for squashfs as the root filesystem.
advantages:
- migrate from a existing -ext4 installation and back
with the sysupgrade utility
- existing partition layout will not be lost during switch
- slightly smaller image size as compared to the -ext4 image.
disadvantages:
- needs f2fs + tools. This is because fstools rootdisk.c decides based
on the partition size (currently root partitions > 100 MiB) f2fs is
used as the rootfs_data filesystem.
- rootfs_data is placed into the rootfs partition after the squashfs.
This makes it difficult for tools that expect a /dev/sda${X} device.
It also makes it difficult for data recovery tools as they might not
expect to find a embedded partition or will be slightly confused.
... or will not support f2fs.
For people with existing build configurations: make sure to include mkf2fs
and f2fsck packages into the image. Otherwise the new -squashfs image will
only boot from the ram-overlay.
Note:
All overlay data (configurations/all installed packages/...) will be
placed in inside the rootfs partition (i.e. /dev/sda2) just after the
squashfs image.
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
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