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 do you mean by lock synchronization, Q. What do you mean by Lock Synch...

Q. What do you mean by Lock Synchronization? Lock Synchronization: In this method contents of an atom are updated by requester process and sole access is granted before atomic

Elaborate the various steps in performing a mail merge, COMPUTER FUNDAMENTA...

COMPUTER FUNDAMENTALS 1. Elaborate the various steps in performing a Mail Merge. Perform one mail merge operation for sending invitation for a conference which is being conduc

What is single program multiple data, Q. What is Single Program Multiple Da...

Q. What is Single Program Multiple Data? A general style of writing data parallel programs for MIMD computers is SPMD (single program, multiple data) means all processors execu

Show the process of message passing, Q. Show the process of message passing...

Q. Show the process of message passing? The subsequent issues are determined by system in process of message passing: 1)  Whether receiver is prepared to receive message

Flowchart, draw the flowchart for operator overloading in c++

draw the flowchart for operator overloading in c++

Explain the essential elements of electronic data interchang, What are the ...

What are the essential elements of Electronic Data Interchange. The necessary elements of Electronic Data Interchange (EDI) are: The use of an electronic transmission me

Compare hypertext versus hypermedia, Compare hypertext versus hypermedia.  ...

Compare hypertext versus hypermedia.  Hypertext is basically similar as regular text - it can be stored, read, searched, or edited - with a significant except ion: hyper text h

Accessing a cache - computer architecture, Accessing a Cache:  Direct ...

Accessing a Cache:  Direct mapping: (Block address) modulo (Number of cache block in the cache) The valid bit indicate whether an entry contain a valid address.

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