Install Yocto image and backup

[Alexander Dahl]

Hei hei,

Am Montag, 2. November 2020, 02:02:09 CET schrieb Jupiter:
> I built Yocto Linux kernel and installed Yocto image to MTD NAND
> storage in an iMAX6 device, because we designed RO for the kernel and
> root file system, RW for applications, we can update applications OTA
> but we cannot update kernel and root file system OTA. My supervisor
> asked if we need to have a dual NAND storage to backup the kernel and
> root file image, if the NAND bad sector occurred in the primary image,
> it can be booted from the secondary backup image. I understand where
> the concerns come from, but I am not clear if it is necessary or if it
> is a common practice to perform NAND backup storage, appreciate your
> insight advice.

In my opinion two things are common practice: 

1) Using a layer on top of raw NAND, like UBI/UBIFS nowadays, so bad blocks 
can be handled properly in a layer below your rootfs.

2) Using an A/B scheme for updating and using a well tested framework for that 
(instead of self written shell scripts).  You don't need another NAND chip for 
that, just multiple partitions.  You can still have your kernel/rootfs read-
only at runtime.

Greets
Alex