Implementing protection with virtual memory, Computer Engineering

Assignment Help:

Implementing Protection with Virtual Memory - computer architecture:

To enable the operating system to implement protection in the VM system, the HW have to:

I. Support at least 2 modes that denoted whether the running process is a user process (executive process) or an operating system process (kernel/supervisor process).

II. Provide a part ion of the CPU state that a user process may read but not write (includes supervisor mode bit).

  • Provide mechanism where the CPU may go from user mode to supervisor mode (accomplished by a system call exception) and vice versa (return from exception instruction).

o   Only operating system process may change page tables. Page tables are held in operating system address space thereby preventing a user procedure from changing them. 

o   When processes desire to share information in a restricted way, the OS have to assist them.

o   The write access bit (in both the TLB and the page table) can be used to limit the sharing to only read sharing.

 


Related Discussions:- Implementing protection with virtual memory

Write a program to input an address, Write a program to input an address i....

Write a program to input an address i.e. 20 Hex and read the byte (char) contents of that address   Answer   include void main() { char prompt; Date: 26th August 2012

Explain instruction stream and data stream, Instruction Stream and Data Str...

Instruction Stream and Data Stream The term 'stream' indicates to a series or flow of either instructions or data operated on by computer. In the entire cycle of instruction ex

What is the difference between vb6 and vb.net, What is the difference betwe...

What is the difference between VB6 and VB.Net? 1,Object-based Language 2,Doesnot support Threading 3 Not powerful Exception handling mechanism 4,Does not having suppor

Performance instrumentation, The performance instrumentation states on how ...

The performance instrumentation states on how to efficiently gather information about the computation of the parallel computer. The process of instrumentation mainly attempts to ca

What is usb, What is USB USB (UNIVERSAL SERIAL BUS) is intended to conn...

What is USB USB (UNIVERSAL SERIAL BUS) is intended to connect peripheral devices like mouse, keyboards, modems and sound cards to microprocessor through a serial data path and

Iot, what is ardiuno explain its working

what is ardiuno explain its working

Explain e-brokerage, E-brokerage. An e-brokerage is an investment house...

E-brokerage. An e-brokerage is an investment house that permits you to buy and sell stocks and get investment information from its Web site.

Dpsd -asynchronous circuits, an asyncronous sequential circuit is described...

an asyncronous sequential circuit is described by the the exitatio function and the output function y=x1x2''+(x1=x2'')y output function z=y a)draw the logic diagram of the circuit.

Explain about the history of magento?, Varien, the company that owns Magent...

Varien, the company that owns Magento, formerly worked with osCommerce. They originally planned to discontinue osCommerce but later decided to rewrite it as Magento. Magento formal

Main problems with evaluation functions, Main problems with evaluation func...

Main problems with evaluation functions: Superlatively, evaluation functions should be quick calculates. Wherever is chance they take a long time to estimate, so after then le

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd