The nature of kernel of the FreeBSD

[Robert Watson]

On Wed, 6 Sep 2006, Mike Meyer wrote:

> In <2699850609061520wad7f0f2s7b402fb7789336ff at mail.gmail.com>, Eder <ederbs.hackers at gmail.com> typed:
>> A doubt,
>>
>> Kernel of the FreeBSD is monolithic, correct !!!
>
> Correct.
>
>> The MacOS is derived from kernel of the FreeBSD, correct !!!
>
> Not correct. The MacOS kernel is derived from Mach, not FreeBSD.
>
> The MacOS userland is mostly derived from FreeBSD, but includes tools from 
> the other BSDs, and the current direction is to mimic the Linux userland 
> (i.e. /bin/sh is bash).

http://fxr.watson.org/fxr/source/?v=xnu-792.6.70

I can't help but wonder: has anyone participating in this thread read any of 
the XNU source code other than me?  Take a look at two subtrees in particular:

bsd/		FreeBSD-derived kernel BSD subsystem, including network stack
 		and VFS

osfmk/		Mach-derived VM, scheduler

The current BSD code in Darwin differs significantly from current FreeBSD, but 
clearly has similar roots.  You'll even find Julian's devfs.

Robert N M Watson
Computer Laboratory
University of Cambridge