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 serial mouse, Q. What is Serial Mouse? Mice that use standard s...

Q. What is Serial Mouse? Mice that use standard serial port are known as 'serial'. Because Serial ports 1 and 4 (COM1, COM4 under DOS, /dev/ttyS0 and /dev/ttyS3 under Unix/GNU-

What property of the architecture of 3g networks, Question: (a) Explain...

Question: (a) Explain how a Mobile Terminating call, from a PSTN phone, is processed in a GSM network. Illustrate your answer with a diagram. (b) Top-Net, a new telecommuni

What is meant by stacked list, What is meant by stacked list? A stacke...

What is meant by stacked list? A stacked list is nothing but secondary list and is showed on a full-size screen unless you have specified its coordinates using the window comm

Explain multihomed host, Write short notes on the Multihomed host. A ho...

Write short notes on the Multihomed host. A host computer that connects to multiple networks is termed as multi-homed host. Multihoming is occasionally used to raise reliabilit

Describe functions of data flow diagram, Describe functions of data flow di...

Describe functions of data flow diagram After you have roughly designed data flow diagram, you could write a description of each function and you could describe the function i

Perform binary addition, Q. Explain the following: a. BCD code b. Gra...

Q. Explain the following: a. BCD code b. Gray code c. Excess-3 code d. True complement method Q. Addition-Subtraction-Multiplication-Division: Perform Binary Addi

Neural network for two predictors thickness, 2) Consider the following neur...

2) Consider the following neural network for two predictors Thickness and Alignment and two classes Print Quality High and Low. Some weights are shown in the table, including weigh

Explain deadlock, What is a deadlock? A deadlock is a situation that ca...

What is a deadlock? A deadlock is a situation that can increase when two units, A and B use a shared resource. Assume that unit B cannot complete its task unless unit A complet

Explain SR latch using nor gates, Q. Explain SR Latch using NOR gates? ...

Q. Explain SR Latch using NOR gates? Let's inspect the latch more closely.   i. Suppose initially 1 is applied to S leaving R to 0 at this instance. The instant S=1 output o

Program testing and debugging, Program testing and debugging: Program ...

Program testing and debugging: Program testing is the method of checking program, to verify that it satisfies its needs and to detect errors. These errors can be of any type-

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