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 the microprocessor development system, Microprocessor development s...

Microprocessor development system Computer systems have undergone many changes recently. Machines that once filled large areas have been reduced to small desktop computer syste

Explain meaning of each field format of icmp header, Give the format of ICM...

Give the format of ICMP header and explain meaning of each field. The format of ICMP header is given below: Internetwork Control Message Protocol (ICMP) ICMP H

Determine the ad hoc testing, Determine the Ad hoc testing - It is a ty...

Determine the Ad hoc testing - It is a type of testing which is performed without the use of planning or/and documentation. - These tests are run only one time unless a defe

Compute total and access methods, Write a program that input (from the user...

Write a program that input (from the user) the number of hours worked and hours pay rate for employees and output their total pay. The program should process an arbitrary number of

Explain assembly program execution, Q. Explain Assembly program execution? ...

Q. Explain Assembly program execution? An assembly program is written according to a strict set of rules. A word processor or editor is used for keying an assembly program in t

Explain busy waiting semaphores, Explain busy waiting semaphores. Weak,...

Explain busy waiting semaphores. Weak, Busy-wait Semaphores: The simplest method to implement semaphores. Useful while critical sections last for a short time, or we

Representation scheme in ai, Representation scheme in AI: • It's fairl...

Representation scheme in AI: • It's fairly trouble-free to represent knowledge in this way. It allows us to be expressive enough to represent largely knowledge, while being co

Illustrate about fifth generation electronic computers, Fifth Generation (1...

Fifth Generation (1984-1990) The advancement of the next generation of computer systems is characterized majorly by the acceptance of parallel processing.  Until this time para

Fetching a word from memory - computer architecture, Fetching a word from m...

Fetching a word from memory: CPU transfers the address of the needed information word to the memory address register (MAR). Address of the needed word is transferred to the pr

Optimal number of disks , John Lindsay sells disks that have 25 software pa...

John Lindsay sells disks that have 25 software packages that show a variety of financial functions, including net present value, internal rate of return, and other financial progra

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