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

Determine in brief about laptop computers, Laptop computers Laptop comp...

Laptop computers Laptop computers have the obvious advantage over desk-top computers (PCs) in that they are fully portable. This is of specific value if a user wishes to do wor

Explain resource dependence, Resource Dependence The parallelism betwee...

Resource Dependence The parallelism between instructions can also be affected because of the shared resources. If two instructions are occupying the same shared resource then i

What is mother board, What is mother board? Mother Board is a main syst...

What is mother board? Mother Board is a main system printed circuit board which having the processor. It will occupy an unacceptably large amount of space on the board.

Xml can play when dynamically generating html pages , Explain the role that...

Explain the role that XML can play when dynamically generating HTML pages from a relational database? Ans) Even if student has never participated in a project involving this typ

linq file extension, What is the LINQ file extension that interacts with C...

What is the LINQ file extension that interacts with Code Behinds objects? Ans) The extension of the file is .dbml

Give difference between assembler and interpreter, Give difference between ...

Give difference between assembler and interpreter. Assembler: It is the translator for an assembly language of computer. An assembly language is a low-level programming langu

Define the while loop, The while Loop The while loop repeats a statemen...

The while Loop The while loop repeats a statement until the test at the top proves false. As an example, here is a function to return the length of a string. int string_leng

Fundamental differences between risc and cisc architecture, Q. Fundamental ...

Q. Fundamental differences between RISC and CISC architecture? Fundamental differences between RISC and CISC architecture. The following table lists following differences:

How to pass data from list to report, How to pass data from list to report?...

How to pass data from list to report? ABAP/4 gives three ways of passing data: ---Passing data automatically using system fields ---Using statements in the program to tak

What happens to logic after synthesis, What happens to logic after synthesi...

What happens to logic after synthesis, which is driving an unconnected output port that is left open (, that is, noconnect) during its module instantiation? An unconnected out

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