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

..binary tree, draw a binary tree from its inorder and preorder traversal s...

draw a binary tree from its inorder and preorder traversal sequences given as follows: inorder: d b g e h a c n f preorder: a b d e g h c f n

Define edge-triggered s-r flip-flop, Define Edge-triggered S-R flip-flop ...

Define Edge-triggered S-R flip-flop Basic Symbol small triangle, called the dynamic input indicator, is used to identify an edge-triggered flip-flop. Truth Table.

What are the two types of branch prediction techniques, What are the two ty...

What are the two types of branch prediction techniques available?  The two types of branch prediction methods are  1) Static branch prediction  2) Dynamic branch predicti

Define wilkes control unit, Q. Define Wilkes Control Unit? Prof. M. V. ...

Q. Define Wilkes Control Unit? Prof. M. V. Wilkes of the Cambridge University Mathematical Laboratory invented the term microprogramming in 1951. He offered a systematic altern

Explain about the cathode ray tube technology, Cathode Ray Tube Technology ...

Cathode Ray Tube Technology (CRT) CRT is an analog device that is used by a digital device - computer. The interface between these two devices is described. The major component

Determine a positive logic system logic state level, In a positive logic sy...

In a positive logic system, logic state 1 corresponds to ? Ans. For positive digital logic, we choose two voltages levels. Higher voltage shows logic 1 and a lower voltage sho

Describe independent loops in fortran, Q. Describe Independent Loops in for...

Q. Describe Independent Loops in fortran? HPF offers extra opportunities for parallel execution by employing the INDEPENDENT directive to declare the iterations of a do-loop is

Effectiveness - efficiency - safety and utility of site, Based on your unde...

Based on your understanding of Unit 2, compile a set of five usability and/or user experience goals which you think will be useful in evaluating the two sites when gathering the in

Naïve bayes algorithm for text classification, Assignment 3: Naïve Bayes al...

Assignment 3: Naïve Bayes algorithm for text classification. First part: In this assignment, we will redo the task of classifying documents (assignment 2) using the same R

What is vector processing, What is vector processing?  There is ...

What is vector processing?  There is a class of computational problems that are beyond the capabilities of a conventional computer. These problems are characterized by t

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