[IOS] Ch2 System Structures #3

Virtual Machines

• A virtual machine takes the layered approach to its logical conclusion. It treats hardware and the operating system kernel as though they were all hardware

• A virtual machine provides an interface identical to the underlying bare hardware

• The operating system host creates the illusion that a process has its own processor and (virtual memory)

• Each guest provided with a (virtual) copy of underlying computer

[IOS] Ch2 System Structures #2

 

Types of System Calls

• Process control
• end, abort
• load, execute
• create process, terminate process
• get process attributes, set process attributes
• wait for time
• wait event, signal event
• allocate and free memory

• File management
• create file, delete file
• open, close
• read, write, reposition
• get file attributes, set file attributes

• Device management
• request device, release device
• read, write, reposition
• get device attributes, set device attributes
• logically attach or detach devices

• Information maintenance
• get time or date, set time or date
• get system data, set system data
• get process, file, or device attributes
• set process, file, or device attributes

• Communications
• create, delete communication connection
• send, receive messages
• transfer status information
• attach or detach remote devices

• Protection

[IOS] Ch2 System Structures #1

       We can view an operating system from several vantage points. One view
focuses on the services that the system provides; another, on the interface that it makes available to users and programmers; a third, on its components and their interconnections. In this chapter, we explore all three aspects of operating systems, showing the viewpoints of users, programmers, and operating-system designers. We consider what services an operating system provides, how they are provided, how they are debugged, and what the various methodologies are for designing such systems. Finally, we describe how operating systems are created and how a computer starts its operating system.

-- Operating System Concepts 8th, by Silberschatz, Galvin, Gagne