We have ported our BASIC compiler for ARM to the Seeed XIAO SAMD21, RP2040 and NRF52840 boards. That BASIC has a set of runtime routines that are resident on the ARM to handle floating point, string, printf type functions and of course program download. That runtime is written in C.
And that C is compiled with gnuarm’s arm-none-eabi-gcc. To launch that compiler we use a home grown development environment called MakeItC that is written in Tcl. It is a very light weight set of routines totalling less than 2 MB ( NOT GB ) and runs on WIndows, Linux or Rasberry Pi. It includes an automated process to chase down compile and link all #include’d header files looking for .c or .cpp files to compile or .o files to link in.
All running on bare metal. Give it a try, we’d love feedback – even negative.
If I can scrounge up a modern Mac I’ll port it there too.
https://www.coridium.us/coridium/blog/the-big-release
One of our BASIC examples treats BLE as another serial port and can communicate with nRF Connect app on your phone.
Oh yeah, downloads are FREE.