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 compound statement, What is compound statement If we wish to ha...

What is compound statement If we wish to have more than one statement following the if or the else, they should be grouped together between curly brackets. Such a grouping is c

Which techniques are utilized to gain on the number pairs, Which techniques...

Which techniques are utilized to gain on the number pairs and also explain how it helps in connecting number of subscribers. In rural areas, subscribers are usually dispersed.

Determine the term - artisan software and bridgepoint, Determine the term ...

Determine the term - ARTiSAN Software and  BridgePoint ARTiSAN Software : This provides a variety of UML based CASE tools, which also includes a real time modeling tool.

Search methods and heuristics - artificial intelligence, Search Methods and...

Search Methods and Heuristics - Artificial intelligence: Here now we come to the question of how constraint solvers search for solutions -constraint preserving coursework of v

Vliw instruction word, VLIW instruction word is compacted to have floating-...

VLIW instruction word is compacted to have floating-point addition, one branch, floating point multiply, and one integer arithmetic and load/store operation as displayed in Figure

Project cost, I need help in my M.Sc project ,but im wondering how the cost...

I need help in my M.Sc project ,but im wondering how the cost is calculated

Difference between next and continue clause, The difference among the next ...

The difference among the next and continue verb is that in the continue verb it is used for a situation where there is no EOF condition that is the records are to be accessed again

Convert hexadecimal bch to decimal number, Convert hexadecimal BCH to decim...

Convert hexadecimal BCH to decimal of form 0100 1000. Converting the hexadecimal BCH to decimal number firstly convert given number into two's compliment that is: 0100100

Cg, 1. How can you divide the screen into quadrants? Is the process called ...

1. How can you divide the screen into quadrants? Is the process called as ‘viewing transformations’?

Illustrate some notations of object modeling notations, Illustrate some not...

Illustrate some notations of object modeling notations A classifier is a mechanism which describes behavioural and structural features. In UML significant classifiers are cla

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