Dear Brendan,
In message 5663B74E.7000204@etrix.com.au you wrote:
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 ?
Define a set of boot commands, say bootcmd1, bootcmd2, ... and then simply do
run bootcmd1; run bootcmd2; ...
The furst one that succeeds will not return.
Note that the key problem with such a simplistic approach is that it will not help you in case an image looks OK, but hangs during boot - in that case, you need a watchdow and support for the bootcount feature.
Best regards,
Wolfgang Denk