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

Why java is called machine independent, Why Java is called Machine Independ...

Why Java is called Machine Independent? While a java program is compiled this is not converted in an executable code. Rather, this is converted in a byte code. Byte code is hig

Define intranet, Intranet : An Intranet is a type of information system...

Intranet : An Intranet is a type of information system that facilitates communication within the organizations between widely dispersed departments, divisions, and regional loc

Translation look aside buffer - computer architecture, Translation Look asi...

Translation Look aside Buffer :    A TLB is a cache that holds only page table mapping If there is no matching entry in the TLB for a page ,the page table have to

Explain about the various uses of artificial intelligence, Discuss the use ...

Discuss the use of Artificial intelligence techniques in E-Commerce applications. Explain about the various uses of Artificial Intelligence in Medicine field. Justify it with pr

#dbms., #example of cascading rollback#

#example of cascading rollback#

What is the demand of mobile application developers, Desktop based IT appli...

Desktop based IT application is present but the mobile is future. All the applications that were made to work only on counter top are being ported to mobile. In the coming 10 years

Granularity-concept of parallel execution and concurrent , Granularity ...

Granularity Granularity refers to the quantity of computation done in parallel relative to the dimension of the entire program. In parallel computing, granularity is a qualitat

What is the chief advantage of using virtual packets, What is the chief adv...

What is the chief advantage of using virtual packets instead of frames? The router can't transfer a copy of a frame from one kind of network to another since the frame formats

State the advantages off-the-shelf, State the advantages Off-the-shelf ...

State the advantages Off-the-shelf -  tends to be less expensive as development costs can be spread over many users -  can be more sophisticated as large sales bring in c

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