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

Build a program to maintain his personal account, Aim: Build a program or a...

Aim: Build a program or application which gives an interface to the user to maintain his personal account for E-mails & should be able to work on the following applications. Des

What are the address-sequencing capabilities, What are the address-sequenci...

What are the address-sequencing capabilities required in a control memory? i. Incrementing the control address register ii. Unconditional branch as specified by address fiel

Give brief description about arithmetic processing unit, Give brief descrip...

Give brief description about arithmetic processing unit To execute the arithmetic operations there is a separate section known as arithmetic processing unit in CPU. The arithme

Name the popular security measures, Name the popular security measures ...

Name the popular security measures A number of security products covering a broad range of methods are available in the market. Most popular of all the security measures are th

Computer Architecture, As an advocate of CISC architecture to RISC architec...

As an advocate of CISC architecture to RISC architecture, what are the merits and demerits of CISC to RISC architecture

What are the functions of dispatcher, What are the functions of dispatcher?...

What are the functions of dispatcher? There are four fuctions of dispatcher:- A)  Equal distribution of transaction load to the work processes.  B) Management of buffer a

Differentiate between synchronous and asynchronous i/o, Differentiate betwe...

Differentiate between synchronous and asynchronous input/output with the help of an example. The input-output operation is asynchronous input/output operation since after the s

Determine about the security methods, Determine about the Security methods ...

Determine about the Security methods Security methods also protect information from accidental or intentional modification, manipulation or destruction. Most security experts o

Boardcoloring, write a java program to board coloring

write a java program to board coloring

Write a program to find 2''s complement of a binary number, Q. Write a pro...

Q. Write a program to find 1's and 2's complement of a Binary number. Perform necessary checking that if entered number is not a valid number, ask user to enter valid Binary n

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