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

Data stream and instruction stream-flynn’s classification, Data Stream an...

Data Stream and Instruction Stream The term 'stream' refers to an order or flow of either data operated or instructions on by the computer. In the complete chain of instructi

What is a abap/4 module pool, What is a ABAP/4 module pool? -Every dynp...

What is a ABAP/4 module pool? -Every dynpro refers to exactly one ABAP/4 dialog program. Like a dialog program is also known as a module pool ,since it having on interactive mo

Explain biometric systems, Explain Biometric Systems Biometrics is the ...

Explain Biometric Systems Biometrics is the science of measuring physical properties of living beings. Biometric Authentication (1) Biometric authentication is the aut

Decision tree learning, Decision Tree Learning: Furthermore there is s...

Decision Tree Learning: Furthermore there is specified in the last lecture such as the representation scheme we choose to represent our learned solutions and the way that we l

Sorting, Different sorting algorithm will be discussed in the lecutres. The...

Different sorting algorithm will be discussed in the lecutres. The task in this worksheet is to write a funtions based on the Quicksort algorithm. When sorting an array of objec

Message passing programme development environment, In a multicomputer syste...

In a multicomputer system the computational load amid different processors should be balanced.  To pass information between different nodes message passing technique is used. The p

Explain the numbering plan for isdn address structure, Explain the numberin...

Explain the numbering plan for ISDN address structure. The numbering plan for ISDN is evolved with using the following guidelines: 1. This is based on, and is an improvemen

create a class called auditorium, Create a class called auditorium that sp...

Create a class called auditorium that specifies the seats in the auditorium. The class should include at least one data item: seat (two dimensional array of Char) and at least thre

What is a union, What is a union ? A union, like a structure, is a derive...

What is a union ? A union, like a structure, is a derived type. Unions follow the same syntax as structures but have members that share storage. A union type defines a set of alt

Determine the signed numbers are used in binary arithmetic, When signed num...

When signed numbers are used in binary arithmetic, then which one of the notations would have unique representation for zero ? Ans. When signed numbers are utilized in binary ar

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