Implementing protection with virtual memory, Computer Engineering

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.

 

Posted Date: 10/13/2012 6:00:07 AM | Location : United States







Related Discussions:- Implementing protection with virtual memory, Assignment Help, Ask Question on Implementing protection with virtual memory, Get Answer, Expert's Help, Implementing protection with virtual memory Discussions

Write discussion on Implementing protection with virtual memory
Your posts are moderated
Related Questions
Q. Write a program to perform multiplication of two numbers in specified radix. Check that entered numbers are in specified radix or not else error message should be displayed.

Give the details of excess 3 codes and gray code using four binary digits. Ans: Table of excess 3 codes and gray code using four binary digits Binary

Q. Explain RBY and CMYK colour Printing? For good printing printers don't use RBY in place of that they use CMYK (Cyan instead of Blue, Magenta instead of Red, Yellow and a sep

The situation when both transmitter and receiver have to work in tandem is referred to as? The situation while both transmitter and receiver have to work into tandem is termed

What is cache memory? The small and fast RAM units are known as caches. When the implementation of an instruction calls for data located in main memory, the data are obtained a

Rhythm Rhythm in art refers to the way that your eye moves through a picture and can be thought of in a similar way to rhythm in music. Your eye will move through some picture

Program Level This is normally the liability of OS (operating system) that runs processes simultaneously. Different programs are generally independent of each other. So paralle

1. Enter your "E-mail address" and "Real Name" (or whatever name you need to call yourself) in the spaces given, then select the "Create Account" button. 2. Within moments, you

Explain about subsystem and object of object oriented modeling A subsystem is a grouping of elements of that constitutes a specification of behaviour offered by other contained

SGML is very large, influential, and difficult. It has been in important industrial and commercial use for nearly two decades, and there is a important body of expertise and softwa