If you run the command as a query you should see something like:
Total APP partition size: 261886 kB
That will list the sizes of the partitions. The one you care about for your rootfs is “SYSTEM”. Depending on how large it is you can steal some space from the subsequent partitions without too many consequences. e.g. increase size by 10MB …
Some stuff you should be aware of:
This is destructive. If you move a boundary for a partition it will be deleted.
- Be very careful to make sure the numbers add up. You don’t want to brick your device which is entirely possible.
- Maybe you should try booting from NFS or SD card first. There are examples in the README for the Yocto build.