Hi,
I have the latest version of SAMD boards 1.6.20 installed in IDE 1.8.8. I can't compile a custom bootloader using the Makefile because I get error... fatal error: sam.h: No such file or directory. I had the same error when I tried to create a project in ATMEL Studio 7 from Arduino sketch, but managed to fix that by following the instructions from this post https://forum.arduino.cc/index.php?topic=382953.0 by adding the correct path to sam.h in the projects toolchain.
Now I am trying to run the bootloader Makefile from within CigWin64. and it compiles up to the #include <sam.h> where it fails. Can anyone that actually knows how to use a computer suggest a fix? <sam.h> must point to a directory somewhere, where can I find the reference to this location and change it to point to the correct location of sam.h?