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 pipeline speedup, Define pipeline speedup. S(m)=T(l)/T(m) Whe...

Define pipeline speedup. S(m)=T(l)/T(m) Where T(m) is the execution time for some target workload on an m-stage pipeline. T(l) is the execution time for some workload an

Define arithmetic pipelines, Arithmetic Pipelines The technique of pipe...

Arithmetic Pipelines The technique of pipelining can be applied to various complex and low arithmetic operations to speed up processing time. Pipelines used for arithmetic calc

Change to palindrome, given a string S convert it to palindrome by doing ch...

given a string S convert it to palindrome by doing character replacement.convert S to palindrome with minimum character replacements

Dbms, what is cascading rolback?

what is cascading rolback?

What is usb, What is USB USB (UNIVERSAL SERIAL BUS) is intended to conn...

What is USB USB (UNIVERSAL SERIAL BUS) is intended to connect peripheral devices like mouse, keyboards, modems and sound cards to microprocessor through a serial data path and

Explain microcode and VLSI technology, Q. Explain Microcode and VLSI Techno...

Q. Explain Microcode and VLSI Technology? It is considered that CU of a computer be assembled using two ways; create micro-program which execute micro-instructions or construct

Average waiting time, Customer arrivals at a gas station can be characteriz...

Customer arrivals at a gas station can be characterized by exponential distribution with mean of 10 minutes. The amount of time they take to pump gas can be characterized by an ex

Explain top-down parsing, Explain Top down parsing. Top down parsing...

Explain Top down parsing. Top down parsing: Specified an input string, top down parsing tries to derive a string identical to this by successive application of grammar rule

Find the boolean expression for the logic circuit, Find the boolean express...

Find the boolean expression for the logic circuit shown below. Ans. Output of Gate-1 (NAND) = (AB)' Output of Gate-2 (NOR) = (A'+B)' Output of Gate-3 (NOR) = [(AB)' + (

Explain the term- tracker ball and braille printers, Explain the term- Trac...

Explain the term- Tracker ball and Braille printers Tracker ball Easier to use than a mouse if people have problems using their arms and hands or if they have a coordinati

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