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

Why have companies gone ecommerce, One of these objectives is related to co...

One of these objectives is related to costs. By going e-commerce, consumers will be able to submit their purchase requests to the sellers without paying a visit to their place. Thi

Move a layout cell, If you need to line up the cells next to each other you...

If you need to line up the cells next to each other you can resize and move layout cells as you need. You can change size of a layout cell by using one of its resize handles. Yo

What are conditional chain statement, What are conditional chain statement?...

What are conditional chain statement? ON CHAIN-INPUT similar to ON INPUT. The ABAP/4 module is called if any one of the fields in the chain having a value other than its in

Explaintask and parallel task, Task   A task is logically discrete ...

Task   A task is logically discrete section of computational work. A task is normally a program or else set of instructions which are executed by a processor. Parallel

Draw and elucidate the block diagram 8259, Draw and elucidate the block dia...

Draw and elucidate the block diagram of programmable interrupt controller 8259. The 8259A adds 8 vectored priority encoded interrupts to microprocessor. It can be expanded to 6

The first digit of a decimal constant, The first digit of a decimal constan...

The first digit of a decimal constant must be Decimal constants having of a set of digit, 0 to 9, preceded by an optional - or + sign.

#microprocessor, Program to transfer 10 byte of data from DMS to EMS using ...

Program to transfer 10 byte of data from DMS to EMS using 8086 instructions

What is gimps native graphics file format, XCF is GIMP's "native" format. T...

XCF is GIMP's "native" format. This will preserve all information about an image, having the layers.

Which function type is used for using "at exit-command", Which Function typ...

Which Function type has to be used for using "at exit-command" ? To Use AT EXIT - COMMAND, We must assign a function Type "E" to the relevant function in the MENU Painter OR S

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