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

Explain protection mechanism, Explain Protection mechanism. Protection...

Explain Protection mechanism. Protection mechanism: The subsequent mechanisms are commonly utilized for protecting files having programs and data. (a) Access controls list

Mplement a second-order low-pass filter using the finite dif, you will impl...

you will implement a second-order low-pass filter using the finite difference method. The finite difference method is a useful mathematical method that is used to numerically solve

Common functions of interrupts - computer architecture, Common Functions of...

Common Functions of Interrupts: An Interrupt transfers control to the interrupt service routine, generally through the interrupt vector table, which contains the addresses

What is insertion sort, What is insertion sort? Insertion Sort : One o...

What is insertion sort? Insertion Sort : One of the easiest sorting algorithms is the insertion sort. Insertion sort having of n - 1 passes. For pass p = 2 by  n, insertion so

Permanently resident pages - main memory, Permanently resident pages: ...

Permanently resident pages: Every virtual memory systems have memory areas that are "pinned down", for example cannot be swapped out to secondary storage, for instance:

Symbolic reasoning, An expert system also represents knowledge symbolica...

An expert system also represents knowledge symbolically as sets of symbols that stand for problem concepts. In AI jargon symbol is a string of characters that stands for

Describe data structures used during passes of assembler, Describe Data str...

Describe Data structures used during passes of assembler and their use. During passes of assembler, the Data structures define as: Pass 1 data base Input source pro

Is it possible to change the color and font of the sheet tab, Yes we can mo...

Yes we can modify the color of sheet tabs. By right clicking on sheet tabs and you will get option change color but you didn't find any option to modify the font of sheet tabs.

Fuzzy logic - artificial intelligence, Fuzzy Logic - artificial intelligenc...

Fuzzy Logic - artificial intelligence: In the above logic, we have been concerned with truth whether propositions and sentences are true. But, with some natural language statem

What are privileged instructions, What are privileged instructions?  So...

What are privileged instructions?  Some of the machine instructions that might cause harm to a system are designated as privileged instructions. The hardware permits the privil

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