My hex file covers about 50k, the .hex is basically a set of commands and data that tells the programmer where to modify the blank flash. When erased the flash is all FF's. Hex2bin is generating a 64k image in the .bin file. The difference between my 50k and the 64k is filled with zeros. I want to fill it with FF, that way the actual data in the flash will be the same regardless of programming method.

This is for a rack-based phone switch. In either scenario the board is programmed via the backplane through an FPGA, but I wrote my programming code to receive a .hex file and the software group wants a .bin file.

I just read your other reply. If you don't use /Pn you get zeros. Regardless of what I try I still get zeros. If I can pad with FF the checksum of the .hex and .bin programming methods will be the same (and my headache will go away).