bare-metal-ruwm.md

Bare-Metal RUWM

Can we use RUWM as an ongoing litmus test for our bare-metal portfolio readiness?

Stuff that RUWM core would need to run on bare-metal:

• An executor - can be either embassy-executor or edge-executor (as ESP bare-metal has a generic allocator now) and we can make it configurable
• Blocking or async drivers for SPI, I2C, one-shot calibrated ADC and pin peripherals (pin peripherals need interrupt support)
  • Blocking drivers
    • ADC
      • Need to implement calibration
    • GPIO
    • I2C
    • SPI
  • Async drivers
    • ADC
    • GPIO
    • I2C
    • SPI
• Support for WIFI in STA and AP mode, as well as async IP on top
  • STA
  • AP
    • DHCP
  • async
    • Let's wait until we have AFIT for the Xtensa toolchain
• (Easy?) NVS storage abstraction for reading/writing small binary BLOBs. Do we have it? Pointers appreciated.
  • esp-storage exists but is quite low-level
  • We can build a higher-level solution on top of esp-storage
  • While not strictly necessary, maybe we want compatibility with ESP-IDF NVS?
• (Easy?) OTA (with ESP IDF bootloader initially). Do we have it? Pointers appreciated.
  • Experimental project: https://github.com/bjoernQ/esp32c3-ota-experiment
  • Shows the lower-level operations required
  • We could try to build a higher-level interface based on this work
• (Medium/Easy) Support for async HTTP client; perhaps we can work on bug-fixing the one in edge-net?
• (Medium) Support for async HTTP server with WS support; perhaps we can work on bug-fixing the one in edge-net?
• (Hard?) Support for async MQTT client V3.1. Ideas?
• (Hard?) Support for TLS. Ideas?
  • Demo/PoC implementation: https://github.com/bjoernQ/puny-tls
  • mbed-tls should be possible as well for a more "real world" solution
• (Optional) ULP co-processor support, deep sleep mode support

Thanks for the notes @bjoernQ, I've updated the document.