The Dummy Device emulator is a simple device target for playing with the Firmware Transparency environment.
The device persistent state is stored in two files in a directory on disk:
- bundle.json - which contains the ProofBundle from the update
- firmware.bin - the firmware image from the update.
The Dummy Device has a simple "ROM" implementation which is intended to be thought of as a early stage reset/bootloader which validates the proof bundle and asserts that the firmware measurements match the manifest before chaining to the next stage bootloader if validation is successful.
For fun, the second-stage bootloader is implemented as a WASM VM (using the Life VM from the Perlin folks), and the firmware.bin is expected to be a compiled WASM binary. There is an example of such a binary contained in the .../testdata/firmware/dummy_device directory.
The WASM VM currently only provides a simple print(const char*) function (although this
could be extended if required).