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

Which technique allows executing a program not in memory, A set of techniqu...

A set of techniques that allow executing a program which is not entirely in memory is called ? Ans. virtual memory which allows executing a program that is not entirely in me

Explain bootp (boot strap protocol), Explain BOOTP (Boot Strap Protocol). ...

Explain BOOTP (Boot Strap Protocol). TCP or IP designer observed that several of the configuration steps could be combined in a single step if a server was capable to supply mo

Online Library management system, Please help me to do mini Project about t...

Please help me to do mini Project about this by creating simple front and back end by using html and css and any programming language like python,php to connect those front end and

What is closed system, Closed System: It's isolated from environment influ...

Closed System: It's isolated from environment influences. It operates on factors within System itself. It is also described as a System which involves a feedback loop, a control e

How can you show only selected records with a form, How can you show only s...

How can you show only selected records with a form? There are dissimilar ways in which you can limit the records that you will see with a form, you can: Open a form and app

What is code segment, Q. What is CODE SEGMENT? The logical program segm...

Q. What is CODE SEGMENT? The logical program segment is termed as code segment. When linker links a program it makes a note in header section of program's executable file defin

Describe about the database marketing application of olap, Database marketi...

Database marketing tool or application helps a user or marketing professional in determining the right tool or plan for his valuable add campaign. This tool haves data from all sou

Python, When investing money, an important concept to know is compound inte...

When investing money, an important concept to know is compound interest. The equation FV = PV (1+rate)periods . This relates the following four quantities. The present value (PV)

Explain possible attacks on the wired equivalent privacy, Question : (a...

Question : (a) IEEE802.11 supports two types of network architecture, describe these architectures with the support of diagrams detailing the network components. (b) IEEE80

Program level, Program Level This is usually the dependability of the o...

Program Level This is usually the dependability of the operating system, which runs processes simultaneously. Different programs are evidently independent of each other. So par

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