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

Load sharing facility resource management, The primary aims/details of Load...

The primary aims/details of Load Sharing Facility Resource Management Software(LSFRMS) are good resource utilization by routing the task to the most appropriate system and good uti

Interpreter, difference between pure and impute inter preter

difference between pure and impute inter preter

Describe about remote-load latency problem, Q. Describe about Remote-load L...

Q. Describe about Remote-load Latency Problem? When one processor requires some remote loading of data from other nodes then processor has to wait for these two remote load ope

How to build the structure chart, Building the Structure Chart - Proces...

Building the Structure Chart - Processes in the DFD tend to show single module on the structure chart Afferent processes - give inputs to system Central processes -

Calculate max distance so subscriber get speech reproduction, In a subscrib...

In a subscriber loop that contains a series resistance of 300 ohms to protect the batteries in the exchange, a normalized telephone draws 10 mA and its standard input d.c. resistan

Importance of barrier free design and web accessibility, Problem: (a) ...

Problem: (a) Accessibility can be classified as below: (i) Barrier-free design (ii) Web accessibility. Describe the importance of barrier free design and web accessibi

How the at-user command serves mainly in lists, How the at-user command ser...

How the at-user command serves mainly in lists? The AT USER-COMMAND event serves mostly to handle own function codes.  In this case, you should make an individual interface wit

Associativity of connectives - equivalences rules, Associativity of Connect...

Associativity of Connectives : Here brackets are very important in order to tell us where to perform calculations in arithmetic and logic. By using these brackets we evaluate

Determine the block diagram of bcd adder, Determine the block diagram of bc...

Determine the block diagram of bcd adder To add 0110 to binary sum, we use a second 4-bit binary adder. The two decimal digits, together with input-carry, are first added in to

Computer network, how Hierarchical Routing implement in c or cpp

how Hierarchical Routing implement in c or cpp

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