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 known as multiphase clocking, What is known as multiphase clocking?...

What is known as multiphase clocking? When edge-triggered flip flops are not used, two or more clock signals may be required to guarantee proper transfer of data. This is calle

Granularity and , Granularity In parallel computing, granularity is a ...

Granularity In parallel computing, granularity is a important measure of the ratio of computation to communication. Coarse Granularity: relatively huge amounts of computa

Show types under which networks will be divided, What are the two broad typ...

What are the two broad types under which Networks will be divided? Ans: All computer networks fit in one of the two dimensions specifically: a)  Transmission Technology, thi

Digital electronics, what is Asynchronous Finite State Machines?

what is Asynchronous Finite State Machines?

What are the advantages offered by data mining, What are the advantages off...

What are the advantages offered by data mining? Advantages offered through Data Mining are given below: a) Facilitates discovery of knowledge through massive, large data set

Explain all the categories of common control switching, Explain all the cat...

Explain all the categories that are served by Common Control switching. Common Control Switching System: It is a functional block diagram of a common control switching system i

Explain about hard drives, Q. Explain about hard drives? Disks are gene...

Q. Explain about hard drives? Disks are generally mounted on a disk drive which comprises of an arm and a shaft along with electronic circuitry for read-write of data. Disk rot

Dialog-task updates, Dialog-task updates are Synchronous updates.

Dialog-task updates are Synchronous updates.

View the site files, To see a high-level representation of the structure of...

To see a high-level representation of the structure of a local site, you use Dreamweaver's Site Map view. You can also use site map to add new files to the site, to add, remove and

Give example of stack using encapsulation of OOA, Give example of stack usi...

Give example of stack using encapsulation of OOA An example of the Stack.  A Stack abstraction provides methods like pop (), push (), isEmpty(), isFull(). The Stack can be i

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