[U-Boot] u-boot retries with fallback to other images

[Brendan Simon (eTRIX)]

Hi,

Is there any documentation or u-boot support for having a list of boot
images to try, starting with the first in the list, trying 1, 2 or 3
times, then trying the next in the list.

e.g. boot kernel at mmcblk0p3, then mmcblk0p2, then mmcblk1p2, then
tftp/nfs last resort fallback ?
or
    boot off partition 3 of eMMC, then partition2 of eMMC, then
partition 2 of SD card, then tftp/nfs ?

I've seen some info on google that says this is possible.  I'm just
looking for good documentation that can explain how to set it all up.

Thanks,
Brendan.