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

What is the prominence of rs232-c in serial communication, What is the prom...

What is the prominence of RS232-C in serial communication?  Name some application where you see its use.  RS-232 stands for Recommend Standard number 232 and C is the latest re

Explain lan topologies, Explain LAN Topologies and its basic topologies. ...

Explain LAN Topologies and its basic topologies. LAN Topologies: Network topology is a physical schematic that shows interconnection of the various users. There are four fund

Explain busy hour calling rate in telephone traffic, With reference to tele...

With reference to telephone traffic, explain the terms BHCR. BHCR: Busy hour calling rate is explained as the average number of calls originated through a subscriber througho

Importance of spectrum to the mobile sector, (a) The statement "Standards ...

(a) The statement "Standards create markets or markets create standards" has been the subject of considerable debate. Discuss the advantages and disadvantages to having multiple

Phython, super ascii string checker

super ascii string checker

.image forgery detection, what is the code to detect image forgery using Ma...

what is the code to detect image forgery using Matlab..??

Give regular expression for real number, Develop a regular expression for R...

Develop a regular expression for Real number and Real number with optional fraction (i) A regular expression for real number is [+ | -] (d)+. (d)+ (ii) A regular expression

Combinational logic, At a particular moment in time the output of a COMBINA...

At a particular moment in time the output of a COMBINATIONAL logic circuit depends uponthe inputs to the circuit at the same instant.(Unlike sequential logic circuits where the out

How to add cell padding, Q. How to Add Cell Padding? As you can see, te...

Q. How to Add Cell Padding? As you can see, text is too close to the edges of the cells. You will add padding to the cells to leave room between text and cells. 1.  Click in

Search in problem solving - artificial intelligence, Search in Problem Sol...

Search in Problem Solving: If Artificial Intelligence can inform that the other science about anything, it is about problem solving and, in particular, how to research after s

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