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 syntax of mpi_scan function, Q. Define syntax of MPI_Scan  function...

Q. Define syntax of MPI_Scan  function? MPI_Scan (Sendaddr,, Receiveaddr , count, datatype, op, comm): It merges the partial values in p final results that are received in

What are conversion routines, What are conversion routines? Non-standa...

What are conversion routines? Non-standard conversions from present format to sap internal format and vice-versa are executed with so known as conversion routines.

Combinational logic, At a particular moment in time the output of a COMBINA...

At a particular moment in time the output of a COMBINATIONAL logic circuit depends uponthe inputs to the circuit at the same instant.(Unlike sequential logic circuits where the out

Operating system, define request edge and assignment edge

define request edge and assignment edge

Find the boolean expression for boolean algebra, Find the Boolean expressio...

Find the Boolean expression for logic circuit shown in Figure below and reduce it using Boolean algebra. Ans. Y = (AB)' + (A' + B)' = A' + B' + AB' by using Demorgan's Theorem. =

What are the defining traits of an object-oriented language, The defining t...

The defining traits of an object-oriented language are: * Encapsulation * Inheritance * Polymorphism

States the term ip addresses, States the term IP addresses? IP address ...

States the term IP addresses? IP address considers to the name of a computer onto a network, as the Internet. a. An Identifier for a device or computer onto a TCP/IP network

Perfect fundamental logic - artificial intelligence, Perfect fundamental lo...

Perfect fundamental logic - artificial intelligence: However, while it's theoretically  possible to do definite intelligent things (like prove some easy mathematics theorems a

Explain the functioning of firewall using screening router, Explain the fun...

Explain the functioning of Firewall Using Screening Router. Firewall Using Screening Router: The risk of break-within is large along with this form of firewall: Eve

Enginering mechanics, if 2 forces are equal at an angle alpha between them...

if 2 forces are equal at an angle alpha between them - its resultant R and its direction

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