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

Vliw architecture, Vliw Architecture Superscalar architecture was desig...

Vliw Architecture Superscalar architecture was designed to develop the speed of the scalar processor. But it has been realized that it is not easy to execute as we discussed pr

Explain excess-3 and gray code using four binary digitis, Give the details ...

Give the details of excess 3 codes and gray code using four binary digits. Ans: Table of excess 3 codes and gray code using four binary digits Binary

Ict, how to become an ict enginer

how to become an ict enginer

Eequivalences rules, Eequivalences rules: This conveys a meaning that ...

Eequivalences rules: This conveys a meaning that is actually much simpler so than you would think on first inspection.  Hence we can justify this, by using the following ch

Re:- exam help, Hello there i have 4 exams of ICT and i am after a tutor wh...

Hello there i have 4 exams of ICT and i am after a tutor who can help me in those 4 subjects. One hour for each subjects will be good for me as i have sample papers ready for all s

Explain the term electronic data interchange (edi), Explain the term Electr...

Explain the term Electronic Data Interchange (EDI). Electronic Data Interchange (EDI) may be generally easy to understand as the replacement of paper-based purchase orders alon

Assessing heuristic searches-artificial intelligence, Assessing Heuristic S...

Assessing Heuristic Searches Given a specific problem you want to create an agent to solve, there can be more than one way of specifying it as a search problem, more than one o

Highly encoded micro-instructions, Highly Encoded micro-instructions ...

Highly Encoded micro-instructions Encoded bits required in micro-instructions are small. It provided an aggregated view that is a higher view of CPU as just an encoded

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