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

.image forgery detection, what is the code to detect image forgery using Ma...

what is the code to detect image forgery using Matlab..??

Logical functions, Logical functions   We have discussed the If, 'While...

Logical functions   We have discussed the If, 'While and For' Statements, and have used expressions within our syntax i.e.           If ( expression)           Statement 1;

What is public-key infrastructures, a. What are the differences among conve...

a. What are the differences among conventional signatures and digital signatures? Write a short note on "Attacks on digital signature". b. What is Public-Key Infrastructures

Appropriate problems for ann learning, Appropriate Problems for ANN learnin...

Appropriate Problems for ANN learning: Conversely as we did for decision trees there it's important to know where ANNs are the right representation scheme for such job. Howeve

Prove, state and prove distributive law?

state and prove distributive law?

Explain the process of inter-register signalling, Explain the process of in...

Explain the process of inter-register signalling. Registers are utilized in common control exchanges to store and analyze routing data. They are given on a common basis is a

Loop level-parallelism based on granularity size, Loop Level This is...

Loop Level This is one more level of parallelism where iterative loop instructions can be parallelized. Fine Granularity  size is used at this level also. Simple loops in a

Advantages of specifying parameter assignment using defparam, State The adv...

State The advantages of specifying parameter assignments using defparam are: - This method always has precedence over specifying parameters at the instance of instantiation.

What are sequential algorithms, What are Sequential Algorithms? The cen...

What are Sequential Algorithms? The central assumption of the RAM model is that instructions are implemented one after   another, one operation at a time. Accordingly, algorith

Speed of memory versus speed of CPU, In the past there was a large gap betw...

In the past there was a large gap between speed of a memory andprocessor. So a subroutine execution for an instruction for illustration floating point addition may have to follow a

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