Darwin forms the core UNIX-based foundation of Mac OS X. It includes components like the Mach kernel, BSD kernel, and I/O Kit framework. The Mach kernel handles processor and memory management while BSD provides file system and networking services. The I/O Kit framework supports driver development and plug-and-play functionality. Together these components provide features like improved reliability, performance, and premier networking facilities to the operating system.

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Darwin
OS
Prepared By: Patel Nidhi B
131060753016

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AGENDA
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OS X Architecture
Introduction to Darwin
I/O Kit
Networking

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OS X Architecture - overview
o Layered architecture
o Features include
 Improved reliability & performance
 Enhance networking
 Object based system programming interface
 Support for industry standards

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Cont…
o OS manly depend on the Core OS – Kernel OS (Darwin)
o Kernel enhancements for MAC OS X
o Preemption Multitasking – let scheduling process to share time –
supports real time behavior
o Memory Protection
o Improved Networking Facilities
o Support for Macintosh & non-Macintosh File System
o Object- Oriented API

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Introduction- DARWIN
o Its Unix-derived OS core that provides the underlying
foundation for Mac OS X
o Forms core set of components for OS x & iOS
o Open Source Technology
o Same system s/w forms the core – free environment for
Developers

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o Darwin mainly based on
o BSD
o Mach
o Apple Technologies
o Includes the facilities for
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Creating device drivers
Improved reliability and performance
Virtual File System design
Premier networking facility

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Kernel(Darwin) Architecture
o Mainly Include environments
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Mach kernel
BSD
I/O Kit
File System

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Cont..
o Mach
o Manages - Processor Resources (CPU Usage + Memory) Handles Scheduling - Provides Memory Protection - Messaging
Center for entire OS
o Mach Component Provides
 Remote Procedure Calls
 Scheduler support for symmetric multiprocessing (SMP)
 Real time services support
 Virtual memory support

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Cont…
o BSD
o Provides “OS personality” services
o Based on BSD Kernel – FreeBSD
o BSD Component Provides
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File System
Networking
Free BSD Kernel API
Kernel Support for Threads
 Support for syscall

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Cont…
o Networking
o Enhance the BSD network capability for modern features
o Network Address Translation (NAT) & Firewalls
o Networking Component provides
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Support for both IP
MultiHoming
Routing – multicast support
Packet Fltering

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Cont…
o File System
o Support of many file system like ( HFS, UFS, NFS etc.)
o Default File System (HFS+)
o File System Provides
 Enhanced Virtual File System (VFS) – let the file system stackable
 Increased Performance on previous versions

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Cont…
o I/O kit
o Framework for Driver development – many Devices
o Modular and Extensible
o Object oriented i/o architecture – restricted subset of C++
o I/O kit component provides
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True plug and play
Dynamic device management
On-demand loading of drivers
Multiprocessor capabilities

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Kernel Extension
o Gives ability to dynamically load the pieces of Code to
Kernel – KEXTs
o No need to recompile the Kernel – Monolithic

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Thank you…