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

What is paging unit, Paging Unit Paging mechanism functions with 4K -...

Paging Unit Paging mechanism functions with 4K - byte memory pages or with a new extension available to Pentium with 4M byte-memory pages. In the Pentium, with the new 4M-byt

Fixed arithmetic pipelines, Fixed Arithmetic pipelines  We obtain the e...

Fixed Arithmetic pipelines  We obtain the example of multiplication of fixed numbers. The Two fixed-point numbers are added by the ALU using shift and add operations. This sequ

Features of mpi-1, Features of MPI-1 Binding for FORTRAN and C ...

Features of MPI-1 Binding for FORTRAN and C Collective communication Communication domains and Process groups Point-to-point communication Virtual process

Parallel random access machines, PRAM is one among the models which are use...

PRAM is one among the models which are used for designing the parallel algorithm as shown in Figure. The PRAM model comprises the following components: i)  A group of identical

Scoreboards- constrained-random verification methodology, Scoreboards- Cons...

Scoreboards- Constrained-Random Verification Methodology Scoreboards are used to verify that data has successfully reached its destination whereas monitors snoop the interfaces

What are different types of log records, What are different types of Log re...

What are different types of Log records? V1 and V2.  V1 must be processed before V2.  But, we can have more than single V2 logs

Define b2b - business to business, B2B - Business to Business  It is a...

B2B - Business to Business  It is a mode of conducting business among two or more companies over the Internet, rather than more traditional modes like as telephone, mail, and f

Rational performance of an agent - artificial intelligence, Rational perfor...

Rational performance of an agent - artificial intelligence: To summarize, an agent takes input from its violence and affects that environment. The rational performance of an a

Associative array processing, Associative Array Processing Consider tha...

Associative Array Processing Consider that a list of record or a table is stored in the memory and you want to search some information in that list. For example, the list havin

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