Very simple 2.4 GHz WiFi monitor for the BL602 and related boards.
The focus was on the minimal amount of implementation needed to receive frames. No WiFi blobs or similar used and compiles to ~15 KiB.
Received packets are hexdump'ed to the UART (2 MBaud) and the green LED is toggled. Expect to see lots and lots of beacons; see mac.c line 45 for a way to filter them out hardware-side.
Make sure your PATH has the binaries for a riscv64-unknown-elf-gcc toolchain, then run "make". You can get a prebuilt toolchain from SiFive: https://github.com/sifive/freedom-tools/releases/tag/v2020.12.0