Ummm... actually I don't like to increase the memory footprint for all systems for a feature which nearly nobody ever needs. I think it should be possible to print the large capacities without using such data formats (I guess you don't need 64 bit precision).

I guess I can add some #ifdefs around my code (especially the 64bit printing stuff) Hex isn't a problem, and decimal is not a problem as long as the disk is less than 548GB

For the IDE stuff itself, without 64 bit the IDE can handle drives up to 548GB (max sector numbers possible in 32 bit). What if I have a config option to use 64-bit sector numbers, and default to using 32-bit?

(I needed this since our board does have a 250GB disk attached, and I wanted to see the real capacity when booting)