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

Operations of the web, Operations of the Web mainly depend on hypertext as ...

Operations of the Web mainly depend on hypertext as its means of interacting with users. But what is hypertext? Hypertext as such is the same as regular text that is it can be read

Define interrupt, Define interrupt. An interrupt is any exceptional eve...

Define interrupt. An interrupt is any exceptional event that causes a CPUU to temporarily transfer control from its present program to another program , an interrupt handler th

What is null pointer, What is NULL POINTER Inside main, a FILE * called...

What is NULL POINTER Inside main, a FILE * called file. Afterwards, the fopen function, passing it the path to data file, as well as "r", only intending to read from the file.

Weighted harmonic mean and geometric mean, Problem Show which of the w...

Problem Show which of the weighted arithmetic mean, geometric mean or harmonic mean, you would use in each of the following case. Justify your answer in each case. (a)

What is super scalar architecture, Super scalar architecture Pentium m...

Super scalar architecture Pentium microprocessor is organized with three execution units. One executes floating-point instructions and other two (U-pipe and V-pipe) execute in

What are the input devices, What are the Input devices Various devices ...

What are the Input devices Various devices are available for data input on graphics workstations. Most systems have a keyboard and one or more additional devices specially desi

Categorized the optimization transformations, Categorized Optimization tr...

Categorized Optimization transformations The structure of program and the way in that data is defined and used in this provide vital clues for optimization. Optimization t

How to copy several files in one stroke, Q. How to copy several files in on...

Q. How to copy several files in one stroke? The COPY command can also be used to copy several files in one stroke by using wildcards. For example, consider the following comman

Explain about integrated circuit, Q. Explain about integrated circuit? ...

Q. Explain about integrated circuit? An integrated circuit is created on a thin wafer of silicon that is splitted into a matrix of small areas (size of the order of a few m.m.

Explain message, Differentiate between message switching, packet switching ...

Differentiate between message switching, packet switching and circuit switching Message switching: Recourse computer sends data to switching office that stores the data in

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