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

Coding advantages of casex or casez, Coding advantages of casex or casez ...

Coding advantages of casex or casez By using casex or casez has the following coding advantages: -  It reduces number of lines, especially if the number of bits had been m

Is it possible to create graph form spreadsheets, Is it possible to create ...

Is it possible to create graph form spreadsheets For example IF G5 > 100 THEN "Y" ELSE "N" -  It's also possible to create graphs and charts from spreadsheets (such as using

Explain integrated disk electronics devices, Q. Explain Integrated Disk Ele...

Q. Explain Integrated Disk Electronics Devices? IDE devices are associated to PC motherboard by a 34-wire ribbon cable. Common drive used today for workstations has capacities

What is common language runtime, What is "Common Language Runtime" (CLR)?  ...

What is "Common Language Runtime" (CLR)?  CLR is .NET equivalent of Java Virtual Machine (JVM). It is the runtime that changes a MSIL code into the host machine language code,

Compare pre-emptive and non-preemptive scheduling policies, Compare pre-emp...

Compare pre-emptive and non-preemptive scheduling policies. We preempt the currently executing process in preemptive scheduling. In non-preemptive we permit the current process

Connectivity options accessible to internet subscribers, What are the diffe...

What are the different connectivity options accessible to Internet Subscribers? Explain in detail. Internet Connectivity Options: Internet access is perhaps one of the ma

Transaction that are programmed by the user, How the transaction that are p...

How the transaction that are programmed by the user can be protected? By executing an authority check.

Contain your variable names and definitions, Give your analysis for the fol...

Give your analysis for the following problem statement: You require to write a program that calculates the area and perimeter of a rectangle whose dimensions (Length &width) are gi

Minimum number of two input nand gates in assembly line, An assembly line c...

An assembly line consists of 3 fail safe sensors and one emergency shutdown switch. The line must keep moving unless any of the given conditions occur: a. When the emergency swi

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