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

Stencil duplicating, Stencil Duplicating Equipment Required Stenci...

Stencil Duplicating Equipment Required Stencil Duplicator Thermal copier (optional) Electronic stencil cutter Materials Stencil COPY paper Ink Clean

Find 9''s complement for decimal number, Q. Find 9's complement for decimal...

Q. Find 9's complement for decimal number? The 9's complement is achieved by subtracting every digit of number from 9 (the highest digit value). Let's assume that we want to si

Subsequent statements set every element of matrix, Q. Subsequent statements...

Q. Subsequent statements set every element of matrix? Let a= [2,4,6,8,10], b=[1,3,5,7,9], c=[0,0,0,0,0] Consider the subsequent program section FORALL (i = 2:4)   a(i)

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

Differentiate traditional commerce and electronics commerce, Differentiate ...

Differentiate Traditional Commerce verses Electronics Commerce. Identity: Into traditional commerce customers can simply authenticate the identity of a merchant simply throug

Variable-partition multiprogramming, Choose the descriptions below with the...

Choose the descriptions below with the most appropriate memory management scheme (A through D).  Solutions may be used once, more than once, or not at all. A.     Fixed-partitio

Serialized when you perform serialization, What exactly is being serialized...

What exactly is being serialized when you perform serialization? Serialization is the process of changing an object into stream of bytes. We perform it at the time of transpor

Er diagrams, how can I draw er diagram for sell & storage section of a drug...

how can I draw er diagram for sell & storage section of a drugstore?

Determine the number of classes of ip addresses, The total number of class ...

The total number of class of IP address are? The total number of class of IP addresses are 5.

What is swapping, What is swapping?   A process can be swapped out tempo...

What is swapping?   A process can be swapped out temporarily of memory to a backing store and after that brought back in memory for execution as continued.

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