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

What are the uses of interrupts, What are the uses of interrupts?  ...

What are the uses of interrupts?  Recovery from errors Debugging Communication among programs Use of interrupts in operating system

What is the efi shell?, The EFI community has formed an open source shell e...

The EFI community has formed an open source shell environment. Rather than booting directly into a full OS, on some executions, the user can boot to the EFI shell. The shell is an

Write the binary representation of an integer number, The integer n = 3,510...

The integer n = 3,510,593 has hexadecimal representation 0x00359141 (check this with your d2h program), while the double precision, floating-point number 3510593.0 has hexadecimal

Define the difference between static ram and dynamic ram, Define the differ...

Define the difference between static RAM and dynamic RAM? The RAM family comprises two important memory devices that are static RAM (SRAM) and dynamic RAM (DRAM). The main diff

Features and utilities available in java, Explain the features and utilitie...

Explain the features and utilities available in java, which makes it suitable for developing e-commerce applications.     1.  In a network, the transmission of passive informati

Difference between commit-work and rollback-work tasks, What is the differe...

What is the difference between Commit-work and Rollback-Work tasks? Commit-Work statement "performs" many functions relevant to synchronized execution of tasks.  Rollback-work

Minimize the logic function using NAND gate, Minimize the logic function F(...

Minimize the logic function F(A, B, C, D) = ∑ m(1,3,5,8,9,11,15) + d(2,13) using NAND gate with help of K-map. Ans. Realization of given expression by using NAND gates:  In

Explain about the term- reports, Explain about the term- Reports Repor...

Explain about the term- Reports Reports are produced as a result of questions like "how many times has a type of car broken down" or "which cities have the highest house price

Explain the program translation model, Explain the program translation mode...

Explain the program translation model The program translation model makes the execution gap through translating a program written in a programming language, termed as the sou

How to use activex control in .net, How to use ActiveX Control in .Net ? ...

How to use ActiveX Control in .Net ? ActiveX control is a special type of COM component that handles a User Interface. Using ActiveX Control in your .Net Project is even simple

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