Module tasks 

Async tasks running on the firmware.

Two tasks live in this module:

1. usb_run_task : keeps the embassy-usb device stack alive by polling its run future forever. Spawned at boot.
2. dispatch_loop : reads incoming HID reports, dispatches the request to the [CryptoService], and writes the response back. Runs in the main task because it owns the CryptoService.

The dispatch loop also drives the crate::state state machine by posting events on crate::channels::EVENT_CHANNEL:

• Event::PinVerified after a successful verify_pin.
• Event::SignRequested at the start of a sign operation, then blocks on crate::channels::TOUCH_CONFIRMED until the touch task has confirmed the user pressed the button.
• Event::TouchTimeout if the wait runs out.
• Event::SignComplete once the signing call returned.
• Event::ErrorRaised on any service error during signing.

Splitting the device run loop from the dispatch loop is the canonical embassy-usb pattern: the stack handles control transfers and resets transparently while the application owns its own request/response cadence.

Functions

dispatch_loop 🔒

Main request/response loop: read a HID report, dispatch on the opcode, write the response.

handle_close_session 🔒

Synchronous handler: closes the PIN session in the host-side state only, no chip interaction. Always succeeds (idempotent).

handle_emergency_reset 🔒

Handler for the EmergencyReset opcode.

handle_genkey 🔒

handle_get_pin_status 🔒

handle_get_pubkey 🔒

handle_info 🔒

handle_lock_config_zone 🔒

handle_lock_data_zone 🔒

handle_lock_slot 🔒

handle_one_request 🔒

Process one incoming report, write the response into tx_buf, return the number of bytes used.

handle_provision_initial_pin 🔒

handle_provision_initial_puk 🔒

handle_provision_io_key 🔒

handle_provision_slot 🔒

handle_read_config_slot 🔒

handle_read_config_zone 🔒

handle_read_counter 🔒

Read one of the chip’s monotonic counters and return its raw value.

handle_read_slot_block 🔒

handle_read_slot_word 🔒

handle_set_pin 🔒

handle_set_puk 🔒

handle_sign 🔒

handle_unblock_pin 🔒

handle_verify_pin 🔒

handle_write_config_zone 🔒

usb_run_task 🔒

Drive the embassy-usb device stack. Spawn this once at boot.

write_error 🔒

Map a [CryptoServiceError] into a status + payload and write it.

write_lock_error 🔒

Map a service error to a response status, with a lock-specific bias: the chip’s “execution error” during a lock command almost always means the CRC fed by the host did not match the chip’s recomputed CRC. Surface that as the dedicated LockCrcMismatch status to make triage trivial on the host side.

write_status 🔒

Build a response frame in tx_buf and return its length.