Crate hsm_firmware 

Mini-HSM firmware entry point.

Boot sequence:

1. Initialise embassy-rp peripherals.
2. Configure GPIOs:
   • GP15 input with pull-up : touch button (active-low).
   • GP16 output : green status LED.
   • GP17 output : yellow touch-awaiting LED.
3. Build the USB-HID stack and split it into reader/writer.
4. Build the ATECC HAL on I2C0 (SCL=GP5, SDA=GP4).
5. Spawn the auxiliary tasks: USB run, state machine, animation, touch.
6. Fire Event::BootComplete so the state machine leaves the boot state.
7. Enter the dispatch loop in the main task.

static_cell instead of static mut

Two pieces of state need to live in static storage so the embassy USB stack can borrow them with a 'static lifetime: the descriptor buffers and the HID class state. The idiomatic way to allocate these without unsafe is [static_cell::StaticCell], which lets the runtime check at boot that the storage is initialised exactly once. The price paid is a one-shot init call returning &'static mut T; the runtime cost is a single atomic flag flip.

Modules

animation 🔒

LED animation task.

channels 🔒

Global communication primitives between firmware tasks.

hal_rp2040 🔒

ATECC HAL implementation for the RP2040.

state 🔒

State machine task.

tasks 🔒

Async tasks running on the firmware.

touch 🔒

Touch button sampling task.

usb 🔒

USB-HID device stack.

Structs

EmbassyClock 🔒

Clock backed by embassy_time::Instant. Provides milliseconds since boot, monotonic, used by the PIN session timeout.

Statics

HID_STATE 🔒

Storage for the HID class state. Kept separate from USB_BUFFERS because State is invariant over its lifetime parameter, which forces it to share a single named lifetime with the device borrow.

USB_BUFFERS 🔒

Storage for the USB descriptor / control buffers. The contents are borrowed by the USB device for the rest of the program. Initialised once at boot via init.

Functions

__cortex_m_rt_main 🔒

__embassy_main 🔒