Morse Micro 802.11ah HaLow driver

A portable driver for the Morse Micro MM6108/MM8108 802.11ah (Wi-Fi HaLow) transceivers: host-agnostic C that an embedding environment integrates by providing a small configuration header. It presents a compact station model -- a state object holding the lwIP interfaces, a link status that folds the WLAN and TCP/IP state together, and a poll function the host drives.

The vendor stack (morselib) and the transceiver firmware/board-configuration blobs come from the Morse Micro MM-IoT-SDK, included here as the lib/mm-iot-sdk submodule. morselib is a prebuilt library under the Morse Micro Binary Distribution Licence; the driver runs it cooperatively off the host's scheduler through a small OSAL shim -- no vendor RTOS.

Layout

• src/ -- the driver:
  • mm_halow_config.h -- the host integration contract. The embedder provides mm_halow_configport.h (or the file named by MM_HALOW_CONFIG_FILE) supplying atomic sections, a millisecond tick, pin accessors, and the mm_halow_port_* functions (SPI transport, private heap backing, hardware RNG, fallback MAC, optional edge IRQ).
  • mm_halow_ctrl.c -- driver core: init/deinit, connect/scan/status, the morselib event plumbing.
  • mm_halow_lwip.c -- the lwIP netif.
  • mm_halow_hal.c -- morselib's mmhal interface, mapped onto the mm_halow_port_* hooks (SD-over-SPI framing, reset/wake sequencing, firmware/BCF blob serving).
  • mm_halow_osal.c / mm_halow_sched.c -- morselib's mmosal interface: a private heap (morselib allocates from interrupt context, where a host GC must not run) and a cooperative scheduler with a wall-clock budget.
  • mm_halow_pktmem.c -- the packet-memory pool.
  • mmport.h -- morselib's port header (name fixed by the SDK).
• mm_halow.mk -- build fragment for make-based embedders: prebuilt morselib linkage (grouped with the target multilib's libc/libm) and the firmware/BCF blob embedding.
• tests/host -- allocator tests, compiled natively from the real sources (make, make asan).
• tests/qemu -- scheduler tests on a Cortex-M55 under QEMU (make), since the context switch is naked asm that cannot run on the host.

Integrating

1. Add src/ to the include path along with lib/mm-iot-sdk/framework/morselib/include, and compile src/*.c.
2. Provide mm_halow_configport.h; src/mm_halow_config.h documents every hook and fails the build naming whatever is missing.
3. Link the prebuilt morselib and the transceiver firmware blob -- mm_halow.mk does both for make-based builds. morselib is built against newlib and pulls in a few C library functions (sscanf, qsort, setjmp, ...) that in turn reference newlib's syscall back-end (_sbrk, _write, ...). The host must provide that back-end; MicroPython's ports already do. morselib never calls these at run time, so the back-end only needs to satisfy the link -- and _sbrk in particular should fail rather than hand out memory, since the driver runs entirely from its own heap. (If the host links -nostdlib, also group libc/libm with morselib, as the fragment does.)
4. Drive mm_halow_poll() from the host's deferred-work mechanism and call mm_halow_schedule_poll() when the transceiver's IRQ line asserts (or poll by level; the driver checks the line each pass).

The MicroPython network.HALOW binding is the reference embedding.