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 is an xml entity, Problem : (a) Show whether or not a standard for...

Problem : (a) Show whether or not a standard format for representing data, such as XML, is needed. (b) Using an appropriate example, describe how data is organized in a dat

Determine the output of SR flip flop when S=1 and R=0, The output of SR fli...

The output of SR flip flop when S=1, R=0 is ? Ans. When for the SR flip-flop S=set i/p R=reset i/p, as S=1, R=0, Flip-flop will be set means output will be one.

C++, luminous jewels polishing game

luminous jewels polishing game

Determine the simplified sop boolean expression, The Karnaugh map for a SOP...

The Karnaugh map for a SOP function is given below in figure. Determine the simplified SOP Boolean expression. Ans. F= B'C' + A'C'D + B'D'

What is boyce codd normal form, A relation schema R is in BCNF with respect...

A relation schema R is in BCNF with respect to a set F of functional dependencies if for all functional dependencies in F+ of the form a->b, where a and b is a subset of R, at leas

Classes of experts system, 1. The Consultant : A consultant is an experts...

1. The Consultant : A consultant is an experts person who possesses a high level of expertise in the area. He guide and educate the executives regarding establishing the e

What property of the architecture of 3g networks, Question: (a) Explain...

Question: (a) Explain how a Mobile Terminating call, from a PSTN phone, is processed in a GSM network. Illustrate your answer with a diagram. (b) Top-Net, a new telecommuni

Listening sockets, a) What command do you use to list all listening sockets...

a) What command do you use to list all listening sockets? The output should also contain the name of the program to which the socket belongs.   b) Write the command to use to

What is the need of interrupt controller, What is the need of interrupt con...

What is the need of interrupt controller?  The interrupt controller is employed to expand the interrupt inputs. It can handle the interrupt requests from several devices and pe

What is cable modem, Q What is Cable Modem? One more way of accessing I...

Q What is Cable Modem? One more way of accessing Internet currently being developed is use of cable modems. These require that you subscribe to a cable service as well as allow

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