It would be great if we agreed that U-Boot should be able to cope with zImage directly. Adding the necessary support to U-Boot is trivial.
I did come across a ramdom version of U-Boot which could load zImages, but I don't have a pointer to that any more.
Also, does anyone know why U-Boot always prints "loading legacy image" when loading images created with mkimage? Kinda suggests the U-Boot folks think this image format has been superseded by _something_ but I never figured out why.
Cheers ---Dave