I have a PM3 Easy that I purchased quite a while ago that has a ATMEL AT91SAM7S256 on it and I bought a ATMEL AT91SAM7S512 off of Ebay. I am going to replace the chip with the larger one. Will I be able to program the bootloader and firmware through the USB com port? Or will I need to use a JTAG programmer?
It looks like there is an easy way to use a Raspberry Pi as a JTAG programmer.
I am no expert in this area, but assuming that you have replaced the chip you can use openocd and a raspberry pi to bootstrap the firmware. I have never done this but found several pages that detailed the same procedure.