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

Reading every record , You have a file having sporting goods that are sold ...

You have a file having sporting goods that are sold online. Every item record contains the item id, item name, item description, item category, item price, and the units in stock.

Equivalences & rewrite rules - artificial intelligence, Equivalences & Rewr...

Equivalences & Rewrite Rules - artificial intelligence: Along with allowing us to verify trivial theorems, tautologies make us able to establish that definite sentences are say

Algorithmic complexity theory, Algorithmic Complexity theory: Moreover...

Algorithmic Complexity theory: Moreover a similar situation occurs in broad to specific ILP systems when the inference rules are deductive thus they specialize. So at some sta

Define encapsulation- object oriented technology, Define Encapsulation- obj...

Define Encapsulation- object-oriented technology Encapsulation also called as information hiding, is the characteristic of separating the external aspects of an object, from t

State briefly about the register transfer, State briefly about the  Regist...

State briefly about the  Register Transfer A micro operation is a basic operation performed on information stored in one or more registers. The result of operation may replace

Computation step in time complexity of an algorithm, Q. Computation step in...

Q. Computation step in time complexity of an algorithm? So First in the computation step the local processor executes an arithmetic and logic operation. Afterwards the several

Explain the essential elements of electronic data interchang, What are the ...

What are the essential elements of Electronic Data Interchange. The necessary elements of Electronic Data Interchange (EDI) are: The use of an electronic transmission me

Determine capacity in bytes of a certain memory, A certain memory has a cap...

A certain memory has a capacity of 4K × 8 (i)  How many data input and data output lines does it have? (ii) How many address lines does it have? (iii) What is its capacity in bytes

Reduce minimum literals and derive their complements, Q. Reduce following t...

Q. Reduce following to minimum literals and derive their complements. 1. [(AB)'A][(AB)'B] 2. ABC(ABC' + AB'C + A'BC) 3. (A+C+D) (A+C+D') (A+C'+D)(A+D')

Explain traffic handling capacity, Traffic Handling Capacity is given by ...

Traffic Handling Capacity is given by (A)  Switching capacity × Theoretical maximum load (B)  Switching capacity / Theoretical maximum load (C)  Theoretical maximu

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