Firmware documentation


There are two classes of firmware. The operating system runs (usually) out of the onboard EEPROM. It handles communication with the host, command dispatching, timers, interrupts, and memory management. User modules are uploaded to the board and run out of RAM. They are usually drivers of some sort for an external hardware board connected to the controller.

The host sends commands to the system over the serial port. For example, the host may send a command to display a string on the LED display. The operating system will dispatch this command to the video driver, which will modify the video buffer appropriately and then return an acknowledge to the operating system, which will in turn send an acknowledge over the serial port. User modules are also allowed to send asynchronous messages to the host, such as when a button is pressed.

Firmware modules are assembled by cokedasm, which is a version of dasm with many coke-specific modifications. In addition to standard hex output, cokedasm can also output files in a relocatable module format (necessary for uploading to the board), as well as C wrapper functions for module commands and C header files to define symbols. Because all command-specific C code (for Libcoke) is automatically generated by cokedasm, the system is extremely easy to modify. Simply change the assembly source, and Libcoke changes with it! Here are the specifics on using cokedasm.

You normally interface with the controller using Libcoke. But if you are debugging a module or the OS, or you otherwise want to communicate directly with the controller, you use coketerm. Here are the specifics on using coketerm.

Operating System

The current operating system is CokeOS v3, which is really, really cool. The operating system consists of two parts, the kernel and the resource manager, and implements commands for the external host as well as functions for user code.

User Modules

Here are the modules that we have so far. These links detail the external commands provided by the modules, for use from the host. If you want to write a module, try the CokeOS Internal Reference.

The commands are written as Libcoke c functions. If you want to see the exact format of the command, click on the assembly file and read the header.

Use Egfx! It's really cool! Read the Beginner's Guide to Egfx to learn how it works.