Apollo is the on-board debugger and programmer on Cynthion. It is used to load gateware over USB onto Cynthion's FPGA. Alternatively it may be used as an on-board or external debugger for certain other FPGA platforms.
Apollo consists of two main parts: firmware for the on-board debug microcontroller and Python-based software for the host computer.
If you have a Cynthion, Apollo host software is installed automatically as a dependency when you install Cynthion software.
To explicitly install the apollo-fpga Python module and the apollo command-line tool or to upgrade them to the latest version run:
pip install --upgrade apollo-fpga
To upgrade Apollo firmware on a Cynthion it is typically not necessary to compile the firmware yourself. Instead follow Upgrading Cynthion Device Firmware.
To compile and install onto Cynthion run:
$ cd apollo/firmware
$ make APOLLO_BOARD=cynthion get-deps dfu
This will download dependencies, compile the firmware, and install it onto Cynthion with pyfwup and Saturn-V.
Alternatively you can use variables to specify a different board or a fixed hardware revision:
$ cd apollo/firmware
$ make APOLLO_BOARD=cynthion BOARD_REVISION_MAJOR=1 BOARD_REVISION_MINOR=4 get-deps dfu
A specified revision will override automatic hardware revision detection which is supported on Cynthion r0.6 and above. You must specify the revision to compile firmware for a Cynthion older than r0.6.
Once installation is complete, LED A should activate, indicating that Apollo is running.