基本概括

Zircon is the core platform that powers the Fuchsia OS.  Zircon is

composed of a microkernel (source in kernel/...) as well as a small

set of userspace services, drivers, and libraries (source in system/...)

necessary for the system to boot, talk to hardware, load userspace

processes and run them, etc.  Fuchsia builds a much larger OS on top

of this foundation.

The canonical Zircon Git repository is located

at: https://fuchsia.googlesource.com/zircon

A read-only mirror of the code is present

at: https://github.com/fuchsia-mirror/zircon

The Zircon Kernel provides syscalls to manage processes, threads,

virtual memory, inter-process communication, waiting on object state

changes, and locking (via futexes).

Currently there are some temporary syscalls that have been used for early

bringup work, which will be going away in the future as the long term

syscall API/ABI surface is finalized.  The expectation is that there will

be about 100 syscalls.

Zircon syscalls are generally non-blocking.  The wait_one, wait_many

port_wait and thread sleep being the notable exceptions.