I need a USB bootloader for the MK22FX512VMC12 chip. I'm very interested in either the AN4370 or AN4379 software. I was wondering which would be easier to port to the K22? Looking at the directory structure, they both have K20 versions, but the AN4379 does state that the device to run the bootloader must be supported by the USB stack with the MSD class, as well as contain a flash driver. Do these exist (or are easily portable to) the K22?