Kernel Boot Options

I'd initially thought that the first process started by the kernel would be the Python init script, but I've decided to add another step to the TeeOS boot sequence. I'm calling the first process run 'pinit' and it is a statically compiled C binary.

The kernel sets any unrecognized 'key=value' strings at the boot prompt as environment variables. pinit will take advantage of this and it run the interpreter specified on the boot prompt. This allows the specification of which Python to use on the system, should there be more than one version of Python installed. This also makes it possible to test other versions of the interpreter; PyPy for example.

When executed by the kernel, pinit will have PID 1 so it will exec() the Python interpreter passing the specified Python init script as an argument, making the Python script PID 1- the init process.

The currently designed additional boot options are:

PYBIN=/path/to/python
PYINIT=/path/to/python/init

Specifying the interpreter and system init at boot allows testing of of different python versions and different init scripts.