Quanto o BSD está no OSX Lion? [fechadas]

Question

O OSX é comumente visto como o shell gráfico no topo do BSD. Ultimamente, parece que a Apple está adicionando mais e mais à funcionalidade do sistema central (sandbox, versionamento). Existe uma progressão constante para um kernel eventualmente todo-proprietário, ou a abordagem de microkernel é flexível o suficiente para ser persistida?

    

Answer 1

O artigo da Wikipedia sobre XNU responde muito a essa pergunta.

XNU was a hybrid kernel combining version 2.5 of the Mach kernel developed at Carnegie Mellon University with components from 4.3BSD and an object-oriented API for writing drivers called Driver Kit. After Apple acquired NeXT, the Mach component was upgraded to 3.0, the BSD components were upgraded with code from the FreeBSD project and the Driver Kit was replaced with a C++ API for writing drivers called I/O Kit.

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The Berkeley Software Distribution (BSD) portion of the kernel provides the POSIX API (BSD system calls), the Unix process model atop Mach tasks, basic security policies, user and group ids, permissions, the network stack, the virtual file system code (including a filesystem independent journalling layer), several local file systems such as HFS/HFS+, the Network File System (NFS) client and server, cryptographic framework, UNIX System V inter-process communication (IPC), Audit subsystem, mandatory access control, and some of the locking primitives. The BSD code present in XNU came from the FreeBSD kernel. Although much of it has been significantly modified, code sharing still occurs between Apple and the FreeBSD Project.

Portanto, o shell gráfico do OS X não fica no topo de um kernel BSD. O kernel é híbrido e acredito que não seja o mesmo que qualquer kernel em qualquer sistema mainstream do FreeBSD, OpenBSD, NetBSD ou qualquer outra variante BSD. Apenas uma parte relativamente pequena (mas importante) do BSD está no OSX.