Assignment Number 1.docx

Bahria University, Islamabad Department of Computer Science BS IT 6B Assignment Number 1 Submitted By; Malik Waqar Younis (01-235162-026)

Question No 1 According to “stats counter” android is mostly used operating system in the world with 37.55% share in OS market while Windows operating system holds just 1.89% less share than android and is at 35.6%. As android is usually used as Mobile operating system and Windows is used in PC so there is equal demand of both of the operating systems but designing and development of mobile operating systems bring some challenges with itself which are; 

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Mobile phones have less storage capacity than PC’s although some manufacturers are developing phones with high specs but still most of the phones in market has problem of storage so mobile operating system has to designed and developed in a way that it could tackle this challenge efficiently. Battery capacity of mobile phones is always been the big problem and operating system needs to be designed in a way that it could use less energy and produce more work. Most of the mobile phone users need multitasking in their devices and to fulfil this need multicore processors are also being installed in mobile phones so biggest challenge here for OS is to effectively use those multi processors and provide multitasking to users. Security is another big challenge due to increase threats of cybercrime. There are huge number of devices with different screen aspect ratio, different orientation, size and specification are available in market, mobile OS must be able to work on these devices by utilizing the maximum resources of particular device. More and more AI capable application are being developed for devices, an operating system must be capable of running these kind of applications on device.

Question No 2 Open source operating system has many advantages for programmers and students as they are able to update, modify or view code . Lots of people work on open source operating system for debugging, updates, customization and ease of use which brings updates earlier than traditional operating systems where only limited number of people work on updates and maintenance. Open source operating systems are free too which gives advantage to people of third world countries to use genuine copies of operating system instead of illegally downloading paid operating system and populating the devices with computer viruses in process of illegally activating system. Commercial operating system companies usually do

not like the competition that open source operating systems bring because these features are difficult to compete against. Some open source operating systems do not offer paid support programs. Some companies avoid open source projects because they need paid support, so that they have some entity to hold accountable if there is a problem or they need help fixing an issue.

Question No 3 Scenario In order to prevent the program to stuck in infinite loop and not returning the control back to operating system the OS gives a particular time to a process by using timer, after that certain time OS generate interrupt, terminate that process and take back the control.

Question No 4 Set value of timer, Clear memory, turn off interrupts, modify entries in device status table and access I/0 device should be privileged.