[U-Boot-Users] Fail Safe: Redundant U-boot Images in Flash????

[Eisenhut, Daniel (GE Healthcare)]

> Has anyone ever implemented duel U-boot images in flash as a
> fail safe mechanism? A primary U-boot image, and a backup U-boot
> image incase the primary image is invalid.
>
> I understand there needs to be a single boot point with
> verification to determine which image to boot from. Is there a
> mechanism already in U-boot that can do this?

We're looking at doing something similar on an MPC860 with a
first-stage U-Boot that just checksums and jumps to one of two
second-stage U-Boot images that are stored in flash.  This would
allow us to update U-Boot in the field without risk of losing our
bootloader and being left with a dead system.  Of course, this
assumes we keep the initial U-Boot very simple so that we can get
away with never updating it. We haven't started working on it yet,
just discussing at a high level.  Might have some issues with
vectors.

Dan