[yocto] Read-only file system with persistent storage

[Mike Looijmans]

On 16-07-15 13:36, Gary Thomas wrote:
> I'd like to set up a system with a read-only root file system
> along with some persistent read-write storage.  What are the
> [best] options in Poky/Yocto for this?  Is there any support
> for some type of overlay file system?
>
> Thanks for any ideas/pointers

Depends. NOR or NAND flash?

with NOR, you can store a squashfs rootfs into it, and then use another 
portion with jffs2 or ubifs for r/w capability. If you want to be able to 
change 'everything', you can use an overlay fs, this requires some fiddling 
with pivot_root and friends.

with NAND, you'd have to use a fault-tolerant filesystem to store the rootfs. 
Dunno if it's possible to store a squashfs as a volume into ubi. The rest is 
similar to NOR.



Kind regards,

Mike Looijmans
System Expert

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