[Buildroot] designing a firmware update mechanism

[John Stile <john@stilen.com>]

I use buildroot for an embedded project, which has an atmel arm
processor, at91BootStrap on NOR to call uboot (and the reset of the
system) on NAND.

I am trying to devise a brick-safe strategy to update the systems once
created, but I'm making this up as I go for a lack of better ideas.

So far I am trying to split NAND in redundant halves (each with a copy
of uboot + uboot-env + kernel + roofs), and modify at91bootstrap to
choose which uboot to load, based on something inside the uboot-env
areas.

Will I need to compile 2 versions of uboot, differing only in where to
look for the uboot-env, or is there another way?  If so, is there a way
to do this within buildroot, or does uboot need to become an external
project from my buildroot setup?

Could anyone share a firmware update strategy for a project that uses
buildroot, at91bootstrap, and uboot, or is that outside the scope of
this list?

I have not found any built-in mechanisms to handle updates.