Review questions, short explanations

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What is an Operating System?

System View - Operating systems are a resource allocator and control program. In other words, an operating system decides on how to handle requests that utilize our resources in an efficient and fair way. It also controls the execution of programs so that errors won't happen and prevents improper use of the system.

User view - An operating system from the user perspective makes using a computer convenient.

Kernel - Is a main program that is constantly running on the computer. Any other program can be classified as either a system program (that comes with the operating system) or an application program.(In essence the operating system in the kernel program.)

Main components of an operating system - Process/thread Management, Memory Management and File Management.

Summary- An operating system manages the computer hardware and resources, while, providing a user friendly interface for applications and users.

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What are the goals of Operating System? Briefly explain/discuss.

In general operating systems function to execute user programs and makes it so that solving user problems are easier. The two main ways it goes about doing this are:

Efficiency - The operating system manages the systems resources so that we can efficiently use the hardware of our computer to complete tasks in a timely manner.

Convenience - This has to do with making the computer easier to use from both the programmer and user individuals.

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System Calls

A system call will provide the interface between a running program and the operating system. These calls are executed by the kernel.

Types

Process Management

fork()

waitpid()

execve

exit

File Management

open()

close()

read()

write()

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Bootstrap Program

A bootstrap program is loaded at power-up or reboot. It is typically stored in ROM or EPROM, and it is generally known as firmware. It initializes all aspects of a system, loads the operating systems kernel, and begins execution.

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Interrupts