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 generalization, What is generalization? Generalization is a rel...

What is generalization? Generalization is a relationship among a class (super class) and one or more variations of the class (sub classes).It arrange classes by similarities an

Input output in assembly program, Q. Input output in assembly program? ...

Q. Input output in assembly program? Software interrupt is a call to an Interrupt servicing program situated in the operating system. Generally the input-output routine in 8086

Performance of computer system, Performance of computer system: Comput...

Performance of computer system: Computer performance is frequently described in terms of clock speed (usually in MHz or GHz). It refers to the cycles per second of the main cl

Determine about the logical shift, Logical shift A logical shift operat...

Logical shift A logical shift operation transfers 0 through serial input. We apply symbols shl and shr for logical shift left and shift right microoperations, examples:. R1

Cim and holonic manufacturing system, CIM and Holonic Manufacturing System ...

CIM and Holonic Manufacturing System The improvement of computer integrated manufacturing has demonstrated that the automation has the same potential such that of computers in

recycling from e-waste to resources , Make at least 6 web pages with good ...

Make at least 6 web pages with good formatting, color balance and presentation on any one of the following topics:- 1.    Recycling from E-waste to resources 2.    Light and So

Explain about the object identity of object oriented, Explain about the Obj...

Explain about the Object Identity of object oriented analysis Object identity is a feature of an object that differentiates the objects from all other objects in the applicati

The different storage classes in c, What are the different storage classes ...

What are the different storage classes in C?  Storage classes in C  There are four storage classes in C:  a. Automatic storage class:  b. Register storage class:  c

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

Advantage of crc over simple checksum, Why can CRC detect more errors than ...

Why can CRC detect more errors than simple Checksum? There are two purposes a CRC can identify more errors than a simple Checksum. 1. Since an input bit is shifted by all th

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