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

#title.sequential circuit, design modulo 12 up synchronous counter using t ...

design modulo 12 up synchronous counter using t flip flop

Discuss program testing and debugging in detail, Discuss program testing an...

Discuss program testing and debugging in detail. In program debugging and testing significant steps are as follows: a. For the program, construction of test data b. Analy

What do you mean by instruction cycle, Q. What do you mean by instruction c...

Q. What do you mean by instruction cycle? We have considered the instruction execution in previous section. Now let's consider more about different types of instruction executi

Explain call by value and call by reference, Call by value and Call by refe...

Call by value and Call by reference Call by value means sending the values of the arguments- The value of each of the original arguments in the calling function is copied in

Explain the working of static ram - computer memory, Explain the working of...

Explain the working of Static RAM - Computer Memory? SRAM devices tender extremely fast access times (approximately four times faster than DRAM) but are much more expensive to

Computer network, how Hierarchical Routing implement in c or cpp

how Hierarchical Routing implement in c or cpp

What is mask operation, What is MASK OPERATION The mask operation is si...

What is MASK OPERATION The mask operation is similar to selective-clear operation except which the bits of Aare cleared only where there are corresponding 0's in register B. th

By which many computers are connected in geographical area, A large numbers...

A large numbers of computers in a wide geographical area can be efficiently connected using? A large numbers of computers in a broad geographical area can be efficiently linked

Advantages to companies adopting call centres, Advantages to companies adop...

Advantages to companies adopting call centres Computer systems have allowed companies to set up call centres in other nations where potential cost savings can be made. This, of

State the advantages of CMOS, State the advantages of CMOS. Ans. Su...

State the advantages of CMOS. Ans. Subsequent are the advantages of CMOS: Both n-channel and p-channel devices are fabricated on similar substrate. Low power di

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