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

Exponential search, Exponential Search Another alternative to variable ...

Exponential Search Another alternative to variable size decrease-and-conquer search is known as exponential search. This algorithm begins searching at the beginning of the list

Digital forensics, a) What do you meant by digital forensics? b) What ...

a) What do you meant by digital forensics? b) What is the job of Computer Forensic Analyst c) From the point of view of : i. An employer ii. An employee Give thre

Data, Data, information and knowledge - Information System The nature ...

Data, information and knowledge - Information System The nature of information can most easily be defined in the context of its relationship to data and knowledge. Bohn (1994)

Future of hyper threading, Current Pentium 4 based MPUs use Hyper-threading...

Current Pentium 4 based MPUs use Hyper-threading, but the next-generation cores, Woodcrest and Merom, Conroe will not. While some have alleged that this is because Hyper-threading

How are standard query operators useful in linq, Standard Query Operators i...

Standard Query Operators in LINQ can be used for working with collections for any of the following and more. 1. Get total count of elements in a collection. 2. Order the resu

TIME COMPLEXITY, calculate the time complexity of a=(b/c) operation in stac...

calculate the time complexity of a=(b/c) operation in stack

Example of shared programming using library routines, Q. Example of shared ...

Q. Example of shared programming using library routines? Think about subsequent set of statements  Process A                                  Process B                  :

Counter, mod12 counter connection diagram

mod12 counter connection diagram

#title.calomel electrode, explain the construction and working of calomel e...

explain the construction and working of calomel electrode

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