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 working of digital versatile disk, Q. Explain working of Digital Ve...

Q. Explain working of Digital Versatile Disk? With the capacious digital versatile disk (DVD) electronics industry has ultimately found an acceptable replacement for videotape

What is central processing unit, What is Central Processing Unit Centra...

What is Central Processing Unit Central Processing Unit (CPU) performs all the arithmetic and logical calculations in a computer. The CPU is said to be the brain of the compute

What is ternary association, What is ternary association Associations c...

What is ternary association Associations can be binary, ternary, or have higher order. In use, the vast majority of it is binary or ternary associations. Except a ternary assoc

Determine the workarounds in multiple inheritances, What are several issues...

What are several issues for selecting best workarounds in multiple inheritances? Some restrictions methods are used. Use two approaches of delegations, which is an implementati

Find fiber distributed data interconnect is an example of, FDDI (Fiber Dist...

FDDI (Fiber Distributed Data Interconnect) is an example of? Fiber Distributed Data Interconnect is an illustration of token ring.

One pointer variable be subtracted from another, Under what conditions can ...

Under what conditions can one pointer variable be subtracted from another? Pointer subtraction isn't used very much, but can be handy to determine the distances between two arr

Write the game using writing functions, The year is 2199. For many generati...

The year is 2199. For many generations, the robotic Cyleth have faithfully served humanity. However, under the direction of the computerized superintelligence Skyweb, they have tur

Fetching a word from memory - computer architecture, Fetching a word from m...

Fetching a word from memory: CPU transfers the address of the needed information word to the memory address register (MAR). Address of the needed word is transferred to the pr

Connector of conventional keyboard, 5-pin DIN connector: It is the conn...

5-pin DIN connector: It is the connector of conventional keyboard which have 5 pins (2 IN, 2 OUT and one ground pin) used for transfer and synchronization.

The spanning tree of connected graph with 10 vertices, The spanning tree of...

The spanning tree of connected graph with 10 vertices have 9 edges of spanning tree of connected graph with 10 vertices

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