On 09/08/2011 12:51 PM, Eric Olsen wrote: > Apple's OS X. While I suppose this is generally true, in the strictest sense it's only partially true from what I understand. OS X is based on the Mach kernel (Darwin) as well as parts of the FreeBSD kernel. Large chunks of FreeBSD's kernel (actual FreeBSD code I believe) and it's interface are bolted onto the Darwin Mach kernel and provide core functionality. And the entire unix userspace is FreeBSD. And OS X's various frameworks all depend on both the Mach apis and the FreeBSD ones, though it seems to me that most abstractions are done through the FreeBSD posix layer. But it's not uncommon to find Mach calls in OS X software. Otherwise it would be trivial to port OS X software to FreeBSD, or even run OS X binaries on FreeBSD. But that doesn't work because it's not really FreeBSD, and also uses a different executable format (Mach-O I think). As well Darwin implements its own kernel modules.
Anyway, I have a piece of hardware that interfaces some irrigation equipment with an internet-based server. That runs FreeBSD. I suppose it's easier for a company to hack something together with BSD and not worry about the license for the operating system, as far as copyright license compliance goes. But most likely, they chose FreeBSD because the file system (UFS) is very forgiving of power outages and sudden stops (and it's not even journalled). If I could get this closed binary to run on Linux (the opposite of FreeBSD's Linux personality layer), I'd switch the thing over from an ATX-based computer with a spinning disk to a solid state mini server on Linux. To be fair, companies that get into hot water by shipping linux on their devices are simply lazy, and to think that FreeBSD (shipping the real thing, not talking about OS X here) absolves one of any licensing concerns is probably not accurate either. /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
