Can you elaborate a bit more your question? For example, will the variant files that you need work with a third-party board? or it is your own design?
Are you planning to have the variant files available into Arduino IDE? or another environment like Atmel Studio?
I am asking this because adding or updating variant files based on SAM3X8C is not a big deal but it will depend on your hardware and IDE.
In case you have a third-party board, you can generate generic variant files from Atmel Studio that work for it and customize them to the I/O pin definitions (LEDs, buttons, etc.) of the real board.
In case you have your own design, another option is to fork in github to introduce your board and present basic variant.h/cpp and pin_arduino.h files, so that others can help you on this.
Finally, a third option can be to contact directly Atmel SAM-based tech support team (I don't know if they are Microchip now). Good luck.
Im using my own custom designed hardware. But I designed my own hardware to work with the "standard" Due code, thats how it works right now. I basically now just want to redesign my (already working) custom board into something smaller...hopefully using the 100-pin SAM3X8C.
My current board is basically a Due "bare bones" setup (native USB only), with the CAN chips, and a few GP I/O's pinned out. Many of the I/O's arent used....I think Im only using about 20?
Theres actually 3 CAN busses on my current board design... two high speed 500k CAN using the Due's native CAN controllers and the CAN Due code that you made (awesome work, BTW, it works perfectly, and so easy to use!)....and then the third CAN bus on my board is a single-wire 33.3k CAN hooked up to the Due using SPI and an MCP2515.
Im only going to be working with the Arduino IDE for code tweaking/additions/revisions...I dont have Atmel Studio and never used it before unfortunately.
does Atmel studio produce variant files that work with the Arduino IDE?
Do I need to have the "debug" ports available to the Due to work with Atmel studio? My custom design PCB does not have the Due JTAG/debug ports.
Thanks again for the help...its too bad that Arduino never gave the option of selecting the smaller 100-pin "Due"...