I am working on a dev board i designed and I have given up in disgust over ASF. I dont use Windows and I wont use Virtualbox just so I can run Atmel Studio, and using ASF is just painful, and it also seems to be massively bloated. The simplest things grow the code in huge jumps.
That said, I dont want to harp on why I think ASF is so ugly, but as a result, I am writing a low level driver library, targeting code size and performance/power optimised.
My target is the L21, but I imagine it wouldn’t be difficult to make it work on a D21. Anyway, this is for my own use, but it will be open source if anyone wants it. As part of that process, I have just put ARM-CMSIS and ARM-CMSIS-SAM0 on my github. I know I have seen people ask about this in here, so they are at:
So if anyone else is looking for the .svd files for D21/L21 they are there, as well as the CMSIS generated headers for these chips.
If anyone would like me to add any other SAM0 family chips let me know and I can do it easy enough.