> Like if I put the whole of Linux below the syscall interface onto a second CPU and didn't give you the source, but all apps called into it via an RPC interface, you'd probably think it was the greatest open-sourcing ever.
not the greatest open-sourcing ever no :-)
but if you were talking about open-sourcing the application and software running on the first CPU, I would say that yes, the system on the first CPU was open-source, even though it called an independent system that lives on the second CPU.
I don't see this as being significantly different from an Open Source tool that makes calls to Google Maps.
If it's running on a separate CPU, and it's not doing things like sharing memory, then it doesn't count as far as the Openness of the first software.
As others have noted, if you keep drilling down, you get to things like the microcode on the x86 CPU as something that's not open, and that you are accessing through a much higher level API from what the native chip supports. The x86 CPUs can even include compilers to convert the x86 instruction set to lower level code.
Does it make Linux any less free if it's running on a Transmeta CPU than on a 80386 CPU?
Does it make Linux any less free if it's running on vmware emulating a x86 CPU instead of on native hardware?
what about running Linux on an ARM emulator running on Windows instead of on a real ARM chip?
at what point does the manipulation of the commands before they hit the actual circuit mean that the API for those commands is not 'legitimate'?