On Mon, 6 Oct 2008, Dr. Aharon Friedman wrote:
Sorry, I meant BSD. Here is the link: http://www.freebsd.org/news/press-rel-3.html Aharon Friedman
I don't see the origina message you replied to on the list, so am replying to it via your post...
I'm just a lurker, but even I know that only some of the userland apps in OS X are BSD-based. The kernel is mach microkernel based and not even slightly similar.
This claim regarding the kernel is highly inaccurate. There are significant quantities of FreeBSD, Mach, and Apple-originated code in the Mac OS X kernel, both because Apple pulled in a lot of FreeBSD code early on, but also because code moves between the two kernels fairly easily and fairly frequently, and in both directions. You'll find a FreeBSD-derived VFS, network stack, and countless other kernel parts in Mac OS X from their first open source drop forward. More recently, though, you'll find that the Audit implementation present in FreeBSD 6.x and later is based on the Mac OS X kernel audit code, and the TrustedBSD MAC Framework that appeared in Mac OS X Leopard is straight from FreeBSD.
It's certainly true that there's a lot of non-FreeBSD code -- XNU uses the Mach scheduler and Mach IPC, and a quite different driver framework, for example. There's also some convergent evolution: FreeBSD contains a Mach-derived VM that also comes from the original Mach project.
Finally, just to be clear: XNU is not a micro-kernel, even though it contains significant amounts of Mach code. The "microkernel" and remainder of the kernel run in a single address space, and although certain separation is (often) maintained in the source code / abstractions, the Mach, FreeBSD, and device driver parts run in a unified and tightly integrated way.
Robert N M Watson Computer Laboratory University of Cambridge _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
