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 an "on input filed" statements, What is an "on input filed" stateme...

What is an "on input filed" statements? ON INPUT The ABAP/4 module is known as only if a field having the Value other than the initial Value. This initial Value is explain

Why are high-speed memories required, Q. Why are high-speed memories requir...

Q. Why are high-speed memories required? Is the main memory not a high-speed memory? The answer to second question is absolutely 'No' though why so? Then if memories are slowe

Incorporate exception handling, Assignment (to be published later) will req...

Assignment (to be published later) will require you to extend the menu-driven application developed in Assignment 2B, to incorporate the recording details of the doctors who will b

Control signal, justify whether the control signal passes through same bus ...

justify whether the control signal passes through same bus as data ,address and instruction or not?

What is a formal description for a programming language, A grammar for a pr...

A grammar for a programming language is a formal description of ? Structure is a formal description for a programming language.

Explain the term - ancestors, Explain the term - ancestors The ancestor...

Explain the term - ancestors The ancestors of modern age computer were mechanical and electro-mechanical instruments. This ancestry can be traced as back and seventeenth centur

Xor gate, The XOR gate. The exclusive OR or XOR gate is similar to a tw...

The XOR gate. The exclusive OR or XOR gate is similar to a two input OR gate. The output of an XOR gate is logic 1 only when one input or the other input is high and is 0 when

What are the rules of timescale directive, What are the Rules of Timescale ...

What are the Rules of Timescale directive Rules -  'Timescale directive, like all compiler directives, affects all modules compiled after directive,  whether  in  same  fi

Bubbling the pipeline - computer architecture, Bubbling the Pipeline: B...

Bubbling the Pipeline: Bubbling the pipeline (also known as a pipeline break or pipeline stall) is a technique for preventing, structural, data and branch hazards from taking p

Backpropagation learning routine, Backpropagation Learning Routine: Co...

Backpropagation Learning Routine: Conversely as with perceptrons there the information in the network is stored in the weights than the learning problem comes down to the ques

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