[U-Boot] booting multi-image with several embedded dtbs

Hi,

I have a (legacy) multi-image uImage with several embedded dtbs, but no initrd. I.e. one created by something like "mkimage -T multi -d zImage:dtb1:dtb2:dtb3". I thought I could boot that using the bootm command like this

bootm $loadaddr:0 - $loadaddr:3 # choose dtb3

but that fails with

ERROR: uImage is not a fdt

Just doing "bootm $loadaddr" kind of works (in the sense that the kernel starts, and I can see that dtb2 got passed as dtb) fails quite miserably once dtb1 gets interpreted as an initrd - and of course what I want is to be able to choose between the dtbs at runtime.

Yes, we will switch to proper FIT image at some point, but is there any way to use the existing multi-image uImage as described?

Thanks, Rasmus