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

Algorithms, Data array A has data series from 1,000,000 to 1 with step size...

Data array A has data series from 1,000,000 to 1 with step size 1, which is in perfect decreasing order. Data array B has data series from 1 to 1,000,000, which is in random order.

State the structure of verilog code you follow, State the structure of Veri...

State the structure of Verilog code you follow? A good template for your Verilog file is shown below. // timescale directive tells the simulator the base units and precision

Name the four steps in pipelining, Name the four steps in pipelining. F...

Name the four steps in pipelining. Fetch  : Read the instruction from the memory. Decode : Decode the instruction and get the source operand. Execute : Perform the operat

Flow charts, n=(x*2)/(1=0) the value x=0 and is used to stop the algerithin...

n=(x*2)/(1=0) the value x=0 and is used to stop the algerithin.The calculation is repeated using values of x=0 is input. There is only a need to check for error positions. The va

States briefly the generic framework for e-commerce, States briefly the gen...

States briefly the generic framework for e-commerce. Generic framework of e-commerce comprises the Applications of e-commerce (as like banking, shopping within online stores an

What is managed bean or mbean, A managed bean - sometimes simply referred t...

A managed bean - sometimes simply referred to as an MBean - is a type of JavaBean, developed with dependency injection. Managed Beans are particularly used in the Java Management E

What is the difference among a canvas and a scroll panel, Canvas is a compo...

Canvas is a component. ScrollPanel is a container. Canvas is a rectangular area where the application can draw or trap input events. ScrollPane executes horizontal and vertical scr

Define step by step procedure in computer programming, Define Step by Step ...

Define Step by Step Procedure in Computer Programming? The Computer programming is the skill and art of creating a computer program a defined set of instructions in source code

Explain about two-pass assembler, Q. Explain about Two-pass assembler? ...

Q. Explain about Two-pass assembler? Assemblers usually make two or more passes through a source program in order to resolve forward references in a program. A forward referenc

Area under curve, Write a program to find the area under the curve y = f(x)...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve betw   #includ

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