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

Structural classification-flynns classification , Structural Classification...

Structural Classification Flynn's classification examine the behavioural concept and does not receive into consideration the computer's structure. Parallel computers can be cla

Illustrate working of magnetic bubble memories, Q. Illustrate working of Ma...

Q. Illustrate working of Magnetic Bubble Memories? In many materials like garnets on applying magnetic fields certain cylindrical areas whose direction of magnetization is oppo

Explain about iframe, Q. Explain about IFRAME? is an HTML 4.0 addition...

Q. Explain about IFRAME? is an HTML 4.0 addition to frames toolbox. Presently only MSIE supports . Unlike frames created employing and

Which data structures used in language processing, Which structure can be u...

Which structure can be used as a criterion for classification of data structures used in language processing. And. Nature of a data structure, purpose of a data structure and l

Advantages of e-commerce, One of the resources we used was Ajeet Khurana's ...

One of the resources we used was Ajeet Khurana's article that talks about the advantages of e-commerce. It was helpful to gain some background on the variety of benefits the electr

Vector-memory instructions-vector processing, Vector-Memory Instructions : ...

Vector-Memory Instructions : When vector operations with memory M are executed then these are vector-memory instructions. These instructions are denoted with the many function mapp

How are standard query operators implemented in linq, Standard Query Operat...

Standard Query Operators are executed as extension methods in .NET Framework. These Standard Query Operators can be used to work with any collection of objects that executes the IE

What is arithmetic and logic unit, What is Arithmetic and Logic Unit Ar...

What is Arithmetic and Logic Unit Arithmetic and Logic Unit: The ALU is the 'core' of any processor. It implements all arithmetic operations (addition, multiplication, subtract

Explain bitwise-exclusive-or operator, Bitwise-Exclusive-OR Operator: ^ ...

Bitwise-Exclusive-OR Operator: ^ exclusive-OR-expression : AND-expression exclusive-OR-expression ^ AND-expression The  bitwise-exclusive-OR  operator  (^)  compares

Drawbacks of specifying parameter assignments using defparam, The disadvant...

The disadvantages of specifying parameter assignments using defparam are: -  Parameter  is  essentially specified  by  the  scope  of  hierarchies  underneath  which  it exists

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