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 trivial file transfer protocol, What is trivial file transfer proto...

What is trivial file transfer protocol? Explain briefly? Trivial File Transfer Protocol (i.e. TFTP) is helpful for bootstrapping a hardware device which does not have a disk on

Illustrate about fourth generation computers, Q. Illustrate about fourth ge...

Q. Illustrate about fourth generation computers? One of the main milestones in IC technology is Very large scale integration (VLSI) where thousands of transistors can be integr

Two "next screen "attributes, Of the two "next screen "attributes the attri...

Of the two "next screen "attributes the attributes that has more priority is?? Dynamic.

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

Testing project, Design and test the functions that are needed: a.  Test...

Design and test the functions that are needed: a.  Test Main  in the Testing project add a new file main.c. b.  Test Drivers  in the Testing project add 2 new files, testDriver

Explain working of counters, Q. Explain working of Counters? A counter ...

Q. Explain working of Counters? A counter is a register that goes through a predetermined sequence of states when clock pulse is applied. In principle value of counters is incr

Architecture of artificial neural networks, Architecture of Artificial neur...

Architecture of Artificial neural networks: Presumably "Artificial Neural Networks" consist of a number of units that are mini calculation devices. But they take in real-value

Explain file transfer protocol, Explain File Transfer Protocol . FTP is ...

Explain File Transfer Protocol . FTP is utilized to exchange files among computer accounts, to transfer files among an account and a desktop computer (upload) or to access softw

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