The iPhone OS X

The iPhone

Miriam O Connell Caroline Byrnes

Content

Introduction / history. Advantages Apps Architecture 4 layered Operating system. Memory Management CPU Multitasking. The Future

Introduction

Quad-Band Mobile phone with multimedia capabilities.

iPhone OS X- based on Mac OS X• Difference is multi-touch interface and accelerometer support.

Unix kernel. Touch screen. Supports 3rd-party applications.

History

Apple Engineers directed to look into touch screens.

January 2007 iphone announced at Macworld convention.

June 2007: Went on sale in U.S. Spring 2008:available in Ireland. iPhone 3G – with refreshed hardware.

Advantages over other platforms such as Linux and Windows

Aqua UI takes up less system resources than Windows's Aero UI.

Better security Most revolutionary user interface since the mouse

(multi-touch display) Advanced Safari browser: lets you see any web

page the way it was designed to be seen

Applications

Piano App-Turns the

iPhone into a piano

FlightTrack-get Up-to-date flight info

7 Layer Architecture

Diagram of the iPhone's Archicture http://thecoffeedesk.com/news/index.php/2009/05/17/iphone-architecture/

Lower 3 Layers

Processor: Refers to the ARM instruction set and the interrupt descriptor table as set up by the iPhone OS during boot and driver initialization.

Firmware: Although we refer to the entire OS as “firmware”, this layer instead references the chip-specific code that is either contained with memory in/around the peripheral itself, or within the driver for said peripheral (example: touch screen or gyroscope)

Hardware: Refers to the physical chips soldered to the iPhone’s circuit. The actual processor falls under this layer, but the instruction set and in-memory descriptor tables are contained within the “processor” layer.

IPhone OS

Takes up half a GB of devices total storage. Supports bundled apps from apple and third

party developers. Designed to only run software with apple-

approved cryptographic software. Can be overcome by ‘jail-breaking’.

Four Layerd iOS

1) Cocoa Touch Layer (upper layer).

2) Media Layer .

3) Core Services Layer .

4) Core OS Layer (kernel).

Four Layers

1. Upper Layer(cocoa touch layer)

• ULKit framework• Foundation framework

2. Media Layer• Core graphics framework• Quartz core framework• Media player framework

Four Layers cont…

3. Core services layer• Core foundation network – set of c based interfaces that provide

basic data management and service features for applications.• CFNetwork• Security• XML support

4. Core OS layer• Kernel

Memory Management

4) Core OS Layer(deepest layer)

Made up of the kernel environment, drivers and basic interfaces of the OS.

Kernel (Darwin) manages the virtual memory system. The drivers provide the interface between the

available hardware and system frameworks.

Memory Management

4) Core OS Layer(deepest layer)cont

For security purposes access to the kernel and drivers is restricted.

Low level features can be accessed through a set of interfaces (Apps)

This is done using the LibSystem library.

CPU: Features of ARM Processor

High performance integer processor High performance memory system.

-Supports 4-64K cache sizes

-Optional tightly coupled memories with DMA for apps.

-ARMv6 memory system accelerates OS context-switch.

CPU

Powered by ARM class CPU capable of a speed of 667MHz. However, due to power consumption of and operating

temperature, the first CPU ran at 412MHz. If run at full speed, iPhone would have 15% less battery life

and would be warm to the touch. Firmware Update 1.2 then boosted the iPhone clock speed to

533MHz. Kernel level changes counteracted the battery life reduction.

CPU

iPhone 3G S (left) & iPhone 3G (right)

www.wired.com

CPU

Current Spec

RAM: 256MB

Processor: 600 MHz

The iPhone Mac OS X:- Multi-tasking

Multi-tasking

Running two or more programs at the same time on the same single-processor computer.

Iphones 3.X software is a fully pre-emptive multitasking OS.

Does not allow third-party developers to use multi-tasking.

Problems with multi-tasking.• Slows the system down• Increases battery usage• Security(spyware, adware and viruses)

Multi-tasking cont…

Apples Solution…. Push notifications

• Pushes all the data as notifications to inactive iPhone apps.• Saves battery

iPad Based on:Mac OS X v10.5.8 or later

iPad-Benefits

Portable Affordable($499) Cross-compatible with the iPhone

iPad-Limitations

No multithreading. The iPhone OS can't run background

processes. It can't have two apps open at the

same time. Can’t toggle between a Web browser and a word processor.

A lack of support for Adobe Flash.

The Future…

iPhone OS X 4.0 due out this summer Will deliver the features business professionals need. The iPad can then act as a notebook replacement Will provide IT administrators with the functions they

need to effectively manage remote iPhones and iPads. Improved security and encryption features Multitasking-Developers will have access to seven multitasking

services, which will allow tasks to be performed in the background while preserving performance and battery life.

Any Questions

References

http://www.slashgear.com/iphone-3g-s-processor-and-ram-details-revealed-1046618/ http://www.everyipod.com/iphone-faq http://www.macocrumors.com/articles/iphone-cpu-speed/Speed http://www.endgadget.com/2009/06/10/iphone-3g-s-processor-specs-600mhz-cpu-256mb-of-ram/ http://www.apple.com http://www.gsmarena.com/apple_iphone_4g-3275.php http://www.chaione.com/iphone-os-technology-layers/

References

http://en.wikipedia.org/wiki/Architecture_of_Mac_OS_X http://www.wired.com/gadgetlab/2009/06/gallery-

deep-inside-the-iphone-3g-s/ http://developer.apple.com/iphone/library/referencelibrary/GettingStarted/URL_iPhone_OS_Overview/index.html#//apple_ref/doc/uid/TP40007592 http://www.spazioiphone.com/wordpress/wp-content/uploads/2009/05/iphone-multitasking.jpg www.oppapers.com/essays/apple-iphone. http://mad_ip.eu/files/reports/iphone.pdf