Crate identity

Access to unique identifiers provided by the device.

This module provides device_id_bytes() and related functions, which returns an identifier for the concrete piece of hardware that the software is running on in byte serialized form.

Concrete properties of a device identity are:

• Identifiers are reasonably unique: They are either unique by construction (serial number, MAC address) or random identifiers (>= 64 bit).

• The scope of the identifier is within an Ariel OS board. Their scope may be broader, eg. when a identifier is unique per MCU family, or even globally.

• Identifiers do not change during regular development with a device, which includes the use of a programmer. Identifiers may change under deliberate conditions, eg. when a device has a one-time programmable identity, or when there is a custom functionality to overwrite the built-in identifier that is not triggered by the device erase that is performed as part of programming the device.

Constructing an identifier fails rather than produce a dummy identifier.

It is considered a breaking change in Ariel OS if a device’s identifier changes or becomes an error. Errors changing to valid identifiers is a compatible change.

Other identifiers, such as the EUI-48 addresses provided by interface_eui48(), are usually derived from the main identity, but have different properties.

Structs

• Eui48
  An EUI-48 identifier, commonly known as a MAC address.

Functions

• device_id_bytes
  Obtains a unique identifier of the device in its byte serialized form.
• interface_eui48
  Generates an EUI-48 identifier (“6-byte MAC address”) based on the device identity.