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

Binary, 8:1 Mux for a given function, f=S (0, 1,5,7,9, 13)..

8:1 Mux for a given function, f=S (0, 1,5,7,9, 13)..

Explain the criteria to classify data structures, Explain the criteria to c...

Explain the criteria to classify data structures used for language processors? The data structures utilized in language processing can be classified upon the basis of the subse

What is mini computer, Q. What is Mini computer? The term minicomputer ...

Q. What is Mini computer? The term minicomputer introduced in 1960's when it was realized that numerous computing tasks don't need an expensive modern mainframe computers howev

Connection machine fortran, Q. Connection Machine FORTRAN? Connection M...

Q. Connection Machine FORTRAN? Connection Machine Fortran was a subsequent SIMD language developed by Thinking Machines Corporation. Connection Machine Fortran incorporated all

Vliw instruction word, VLIW instruction word is compacted to have floating-...

VLIW instruction word is compacted to have floating-point addition, one branch, floating point multiply, and one integer arithmetic and load/store operation as displayed in Figure

Adbms, what are the different way of executing pipelines

what are the different way of executing pipelines

Define edge triggered d flip flop, Define Edge Triggered D flip-flop? D...

Define Edge Triggered D flip-flop? D latch has only two inputs C(control) and D(data). The operation of a D flip-flop is a lot simpler and it has only one input addition to the

Automated injection, There are tools to automate the process of SQL Injecti...

There are tools to automate the process of SQL Injection into login and other fields. One hacker process, using a one tool, will be to search out a number of weak targets using Goo

What are sewing kits, What are Sewing Kits? Sewing Kits are modules whi...

What are Sewing Kits? Sewing Kits are modules which contain a not used mix of gates, any other cells or flip-flops considered potentially helpful for an unforeseen metal fix. W

What is rational administrator, Use the Rational Administrator to: * M...

Use the Rational Administrator to: * Make and manage projects. * Make a project under configuration management. * Make a project outside of configuration management.

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