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 are the type of internet connection, What are the type of Internet con...

What are the type of Internet connection When determining requirements for a VPN, carefully estimate the number of systems to be put behind the VPN, the number of concurrent u

Find the conversion time & conversion rate of A/D converter, Find the conve...

Find the conversion time of a Successive Approximation A/D converter which uses a 2 MHz clock and a 5-bit binary ladder containing 8V reference. What is the Conversion Rate? An

Which network connects multiple company locations, A/An                net...

A/An                network is typically a company network that connects multiple company locations into a single network. (A)  local area                                  (B

Visual perception problems, In AI the process of perception is studied ...

In AI the process of perception is studied as a set operations. A visual scene may be encoded by sensors and represented as matrix of intensity values. These are processed b

Loop used to show properties, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4  A loop invariant is

Determine how simulation can be developed, Determine how Simulation can be ...

Determine how Simulation can be developed To determine how a simulation can be developed for use in a real situation the below illustration has been chosen. Scenario chosen is

Why a computer expect to receive responses, Why a computer expect to receiv...

Why a computer expect to receive responses when it broadcast an ARP request? Response will be acquired only from the machine for that request is being sent not for the other ma

What kind of system do we need to run gimp, Any system able of run Gnome 2,...

Any system able of run Gnome 2, KDE 3.2, Windows 2000, Mac OS X and later versions should be capable to run GIMP. GIMP's biggest appetite is for memory and how much you will requir

Limitations of execution of instructions, Q. Limitations of execution of in...

Q. Limitations of execution of instructions? 1. Size of memory shown in 16 words while instruction is capable of addressing 210 =1 K words of Memory. However why 210 since 10 b

Assembly language - computer architecture, Assembly language: An assem...

Assembly language: An assembly program has a series of instructions--mnemonics that relate to a stream of executable instructions, when translated by an assembler that may be

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