[U-Boot] Instructions for upgrading U-boot on Marvell OpenRD "Base" computer?

I’ve got an old Marvell OpenRD Base computer that I’d like to install Debian Jessie on.

I believe that I’ll need to up-grade the u-boot on it to handle new features in the Jessie kernel.

I need the following information…

1) Where to get a suitable u-boot image? (Will the one at https://people.debian.org/~tbm/u-boot/2014.10+dfsg1-4/openrd_ultimate/ work?

2) Instructions for upgrading u-boot (via USB stick would be more convenient for me than via tftp) assuming I have a working — but very old — u-boot on the machine at the start?

3) If I upgrade u-boot, will it still work with Wheezy?

Thanks! Rick