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

Define about pascaline - mechanical computers, Pascaline:Mechanical compute...

Pascaline:Mechanical computers Blaise Pascal made the initial attempt in the direction of this automatic computing. He invented a apparatus, which comprised of lots of gears an

Differences between one hot and binary encoding, What are differences betwe...

What are differences between one hot and binary encoding? Common classifications used to explain the state encoding of an FSM is Binary or highly encoded and one hot. A bina

Define the internal users of system, Q. Define the Internal Users of system...

Q. Define the Internal Users of system? Internal Users are employees of business for that an information system is built. Illustration are clerical and service staff, technic

Illustrate fdma and tdma concepts., Mobile Computing 1. What is Wireles...

Mobile Computing 1. What is Wireless Protocol Requirements and also explain in brief medium access control protocol. 2. Illustrate FDMA and TDMA concepts. 3. What are the

Multi-operating systems, The assignment enhances the acquisition of new kno...

The assignment enhances the acquisition of new knowledge through reading, research and practical work in class and at home. It requires critical thinking applied to real life tasks

Instruction pipelines, Instruction Pipelines As discussed previous, the...

Instruction Pipelines As discussed previous, the stream of instructions in the instruction implementation cycle, can be realized through a pipeline where overlapped implementat

What is domain analysis, What is domain analysis? Domain analysis is c...

What is domain analysis? Domain analysis is concerned with devising a precise, concise, understandable and correct model of the real world. Analysis starts with problem statem

What do you mean by data warehousing, What do you mean by data warehousing?...

What do you mean by data warehousing? Data warehouse implies as: a) It is subject oriented b) It is integrated and c) It is time variant d) It is non-volatile colle

Address translation - computer architecture, Address translation: ...

Address translation: Compiler time : If it is known in advance that a program will reside at a particular location of primary memory, and then the compiler can be told to

Explain in brief about the insert operation, INSERT OPERATION The inser...

INSERT OPERATION The insert operation inserts a new value into a set of bits. This is done by first masking bits and then O ring them with required value. For illustration, sup

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