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

How to create a rollover image, Q. How to Create a Rollover Image? A ro...

Q. How to Create a Rollover Image? A rollover image is an image whose display changes when pointer passes ('rolls') over it. You will use Dreamweaver's Insert Rollover Image co

Superscalar processors, Superscalar Processors In scalar processors, on...

Superscalar Processors In scalar processors, only one instruction is implemented per cycle. That means only single instruction is issued per cycle and only single instruction i

Minimization of the logic function using NORgates, Minimize the logic funct...

Minimize the logic function F(A, B, C, D) = ∑ m(1,3,5,8,9,11,15) + d(2,13) using NOR gates with help of K-map. Ans. Realization of given expression by using NOR gates: In POS

Functions in first-order logic sentences, Functions in first-order logic se...

Functions in first-order logic sentences - artificial intelligence: Functions may be thought of as special predicates, where we think of all but 1 of the arguments as input and

Define b2b - business to business, B2B - Business to Business  It is a...

B2B - Business to Business  It is a mode of conducting business among two or more companies over the Internet, rather than more traditional modes like as telephone, mail, and f

Name the approaches used for generating the control signals, What are the t...

What are the two approaches used for generating the control signals in proper sequence? Hardwired control Micro programmed control

Describe the different types of frequency hoping, Question: (a) What ...

Question: (a) What are the main challenges for Mobile Computing? (b) What is the ISM band and what is particular about this frequency band? Name two wireless technologies

C programming, A palindrome is a string that reads the same from both the e...

A palindrome is a string that reads the same from both the ends. Given a string S convert it to a palindrome by doing character replacement. Your task is to convert S to palindrome

Define the concept of inheritance, Define the concept of Inheritance I...

Define the concept of Inheritance Inheritance is property of reusing the code within the object oriented development. While modelling, we look at the all the classes, and try

Multi tasking environment, Q. Explain about Multi tasking environment? ...

Q. Explain about Multi tasking environment? Multi tasking uses parallelism by: 1) Pipelining functional units are pipe line mutually 2) Simultaneously employing multiple

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