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 is a demultiplexer, What is a demultiplexer? Ans: Demultiplex...

What is a demultiplexer? Ans: Demultiplexer: This is a logic circuit which accepts one data input and distributes this over some outputs. This has one data input, m selec

Explain problem-oriented and procedure-oriented language, Explain differenc...

Explain difference between Problem-oriented and procedure-oriented language. Problem-oriented and procedure-oriented language: The programming languages which can be utilized

What is the main use of structures, What is The main use of structures ...

What is The main use of structures The main use of structures is to lump together collections of disparate variable types, so they can conveniently be treated as a unit. For ex

Data dependency, Data Dependency:   It refers to the state in which two or ...

Data Dependency:   It refers to the state in which two or more instructions split same data. The instructions in a program can be given based on the relationship of data dependency

Superscalar processors, Superscalar Processors In scalar processors, on...

Superscalar Processors In scalar processors, only one instruction is implemented per cycle. That means only single instruction is issued per cycle and only single instruction i

Which things should microprocessor validate, Q. Which things should micropr...

Q. Which things should microprocessor validate? A microprocessor should validate: Powerful addressing modes More addressing capability More throughput Po

Define bandwidth, Define Bandwidth? When transferring blocks of data, i...

Define Bandwidth? When transferring blocks of data, it is of interest to know how much time is required to transfer an entire block, as blocks can be variable in size it is use

Bus master - computer architecture, Bus Master: In  computer system,  ...

Bus Master: In  computer system,  bus  mastering  is  a attribute  supported  by  various  bus  architectures  that  enables  a  device linked to the bus to initiate transacti

Describe set-associative mapping, Q. Describe Set-Associative Mapping? ...

Q. Describe Set-Associative Mapping? A third type of cache organization known as set-associative mapping is an improvement on direct mapping organization in that every word of

Write about TSR, Write about TSR TPA also holds TSR (terminate and stay...

Write about TSR TPA also holds TSR (terminate and stay resident) programs which remain in memory in an active state until activated by a hot-key sequence or another event like

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