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

Explain about the term e-cash, Explain about the term E-Cash. E-cash is...

Explain about the term E-Cash. E-cash is cash demonstrated by two models. E-cash has one is on-line form of e-cash, that is introduced by DigiCash that permits for the completi

How to create an html document, An HTML document can be created by using an...

An HTML document can be created by using any HTML editor or text editor such as notepad etc. STEPS FOR CREATING A SIMPLE HTMLPROGRAM   1. Go to Start -> Programs->A

Human computer interaction, Preamble The owner of the local shopping mal...

Preamble The owner of the local shopping mall, MaxiMart, has contracted you to assist in the design of an interactive directory. The interactive directory is to be permanently l

Subtraction of 01000-01001 using 2's complement method, Subtraction of 0100...

Subtraction of 01000-01001 using 2's complement method. Ans. Firstly 1's complement of 01001 is 10110 and 2's complement is 10110+ 1 =10111. Thus   01000 =  01000 - 01001

Obtain 1''s and 2''s complement, Obtain 1's and 2's complement of 1010 usin...

Obtain 1's and 2's complement of 1010 using only four-digit representation. Solution: 1's complement: 1's complement of 1010 is  Please note that wherever you ha

What are the differences between simulation and synthesis, What are the dif...

What are the differences between SIMULATION and SYNTHESIS Simulation synthesis Simulation is used to verify functionality of the circuit.. a) Functional Simulation:stud

Calculate blocking probability in a two stage network, In a two stage netwo...

In a two stage network there are 512 inlets and outlets, r=s=24. If the probability that a given inlet is active is 0.8, calculate: Blocking probability Given: N =M =512,

Explain lexical substitution during macro expansion, Explain Lexical substi...

Explain Lexical substitution during macro expansion ? Lexical substitution is used to produce an assembly statement from a model statement. Model statements have 3 kinds of str

Perform division in binary showing contents of accumulator, Q. Perform divi...

Q. Perform division in binary showing contents of accumulator, B register and Y register during each step. (Accumulator, B, Y are 5-bit registers) 13 / 2

Homework, ECE 3550 DIGITAL DESIGN FALL 2013 Homework Assignment #8 Total: 5...

ECE 3550 DIGITAL DESIGN FALL 2013 Homework Assignment #8 Total: 50 pts. Due 11:30am, Wednesday, November 13, 2013 The Potential Impact of the Google Glass on Personal Computing Sea

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