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

Find out data changing from special code to temporal code, Data can be chan...

Data can be changed from special code to temporal code by using ? Ans. By using Shift Registers data can be changed from special code to temporal code. A Register wherein data ge

Dynamic memory allocation function, Name the dynamic memory allocation func...

Name the dynamic memory allocation function? Three dynamic memory allocation functions are: a) malloc, b) calloc and c) free.

Explain virtual packets, Explain Virtual Packets. The router can't tran...

Explain Virtual Packets. The router can't transfer a copy of a frame from one kind of network to other since the frame formats be different. More significantly, the router cann

Support activities in supply chain management, What are the some support ac...

What are the some support activities in primary functions of Supply Chain Management? To support primary functions of Supply Chain Management there will be a company’s infrastr

Use verilog function to define the width of a multi-bit port, Can I use a V...

Can I use a Verilog function to define the width of a multi-bit port, wire, or reg type? Width  elements  of  ports,  wire  or  reg  declarations  require  a  constant  in  bot

How can we use metropolitan area network, Q. How can we use Metropolitan Ar...

Q. How can we use Metropolitan Area Network? A MAN, essentially a bigger versions of a LAN is designed to extend over an entire city. It may be single network like a cable tele

Analysis of sort bitonic, Analysis of Sort_Bitonic(X) The bitonic sorti...

Analysis of Sort_Bitonic(X) The bitonic sorting network needs log n number of phases for performing task of sorting the numbers. The first n-1 phases of circuit can sort two n/

What types of calendars can you create with google calendar, What types of ...

What types of calendars can you create with Google Calendar? Personal calendars, like default calendar Public calendars, which others can access through the web

Overview of the dreamweaver work area, Q. Overview of the Dreamweaver work ...

Q. Overview of the Dreamweaver work area? Let's start with a brief overview of the Dreamweaver work area. If you haven't already launched Dreamweaver, double-click Dreamweaver

What is relational database, What is relational database? Relational da...

What is relational database? Relational database has data that is perceived as tables. A relational DBMS manages tables of data and associated structures that enhances the func

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