Overview
To make the most of card10's dual-core processor, its firmware will have been divided into two parts: The "main" firmware running on core 0 which will have been called Epicardium and the "user-code" running on core 1. In most cases this will have been Pycardium, our MicroPython port.
Epicardium
Epicardium is based on FreeRTOS. There are a number of tasks that will have been keeping card10 running. These are:
- Dispatcher: The dispatcher task handles API calls from core 1.
- PMIC: The power manager task checks the battery level and other interesting statistics that can be gathered from our power manager IC (MAX77650).
- Serial: Handles serial communication via UART, CDC ACM and possibly Bluetooth.
- BHI160: Housekeeping task for interaction with the BHI160.
Epicardium API
Epicardium exposes lots of functionality via the Epicardium API. The technical details of this API can be found in this :ref:`overview <epicardium_api_overview>`. If you are interested in adding new API calls, you should probably read the :ref:`epicardium_api_guide` guide.
Pycardium
Pycardium is our MicroPython fork. Its purpose is to make it as easy as possible to interact with card10. If you are interested in working on Pycardium, take a look at the :ref:`pycardium_guide` guide.
L0dables
Next to Pycardium, other bare-metal code can also run on core 1. For example,
a Rustcardium or C-cardium. These l0dables must be compiled using our special
linker script and should link against the api-caller library so they can
interface with the :ref:`epicardium_api`.
Note: this feature is disabled by default and has to be enabled at build time.
To do this, run bootstrap.sh with the option -Djailbreak_card10=true
and rebuild the firmware as described in :ref:`how_to_build`.
Program Flow Diagram
The following diagram is a rough overview of the program flow in this fimware:
