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

Explain the term- viruses, Explain the term- Viruses Use of firewalls a...

Explain the term- Viruses Use of firewalls and ant-virus software to prevent viruses entering a computer. It's also sensible not to open attachments/emails from "unknown" sourc

What are the barcode readers, What are the Barcode readers These collec...

What are the Barcode readers These collect data from printed barcodes and allow automatic stock control in, for illustration, supermarkets.

Staircase, What is the aim of a stair case light is controlled by two switc...

What is the aim of a stair case light is controlled by two switches one at the top of the stairs and another at the bottom of the stair

Block diagram of a microcomputer system, Q. Block Diagram of a Microcompute...

Q. Block Diagram of a Microcomputer System? Before going on to consider the I/O sub/systems of a computer, let's discuss how a digital computer system can be realized by a micr

Compact disk read only memory, Q. What is Compact Disk Read Only Memory? ...

Q. What is Compact Disk Read Only Memory? This technology has evolved out of entertainment electronics market where cassette tapes and long playing records are being replaced b

Python implementation of a solver for the desert cro, Python implementation...

Python implementation of a solver for the desert crossing, Python Programming #Minimum 100 words accepted#

C program, a c program to implement multiple stack in a single array

a c program to implement multiple stack in a single array

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