Boot from different partitions based on some condition

[Wolfgang Denk]

Dear Mats,

In message <1024408647.20191212164918 at tele2.se> you wrote:
>
> I want to set up for an upgrade of our embedded system, using a
> special kernel for the upgrade. The standard will be to load the
> system from mtd3 (kernel), mtd4 (devicetree) and mtd5 (rootfs).
>
> When an update is to take place I want to run the upgrade system from
> mtd0.
>
> So basically I need to have some sort of telling U-boot that it should
> launch the upgrade system instead of the standard system.
>
> Any ideas how I set this up?
> How to tell u-boot?
> How to get u-boot to boot from another partition based on a condition
> like that?

In addition to Harald's advice you might also want to consider not
reinventing the wheel yet agaib, but instead look into [1] where all
these issues have already been solved (and tested, with many
projects and a zillion devices in the field).

[1] https://sbabic.github.io/swupdate/

Best regards,

Wolfgang Denk

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