[U-Boot] Multi boot selection scenarios

[Marcel Gielen [Celestia-STS]]

I am looking into some multi boot options and I wonder what the most common ways are of selecting boot configurations.

Suppose I have 2 Linux boot images consisting of kernel, device tree and root fs.

What are the most common ways to set img2 as next active boot image from img1 ?


-          Change the u-boot environment from within the running image by using the userspace utilities.

-          Use some reserved RAM area (only works with warm boot) an read this from u-boot script.

-          Write something in e2prom or serial flash and read it from u-boot script.

-          Hardware based selection  (e.g. switch to GPIO)

Any other options I didn't think of ?

Are there also already some provisions for "fallback options" in case of failed updates ?


Any suggestions are welcome,

Marcel