Cannot define custom board - no way to specify variant

[frankleonrose]

Issue described here: https://community.platformio.org/t/custom-target-for-mbed-atmelsam/9795

Fundamentally, variants_remap.json is a fixed platform file and does not support custom boards.

I propose adding a line to mbed.py allowing one to override the variant name derived from $BOARD and variants_remap.json.

variant = env.BoardConfig().get("build.variant", variant)

[valeros]

Hi @frankleonrose ! I guess the problem here is that atmelsam has quite limited support for mbed framework at the moment. Something happened after v151 and atmelsam disappeared from the official page with supported hardware and we had to lock the mbed build script for atmelsam in a special branch.