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

Discuss in detail about micro computer, Discuss in detail about Micro compu...

Discuss in detail about Micro computer A microcomputer's CPU is a microprocessor. The microcomputer was originated in late 1970s. The first microcomputer was built around 8-bit

What is meant by Wired-AND connection of digital ICs, What is meant by Wire...

What is meant by Wired-AND connection of digital ICs?                                                                                                               Ans: Wir

Show the layout of dvorak-dealey keyboard, Q. Show the layout of Dvorak-Dea...

Q. Show the layout of Dvorak-Dealey keyboard? This was one keyboard layout designed to be a challenger to QWERTY layout. This was designed by August Dvorak and William Dealey a

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

Binary, 8:1 Mux for a given function, f=S (0, 1,5,7,9, 13)..

8:1 Mux for a given function, f=S (0, 1,5,7,9, 13)..

Define secondary memory, Define secondary memory. This memory holds tho...

Define secondary memory. This memory holds those pages that are not present in main memory. The secondary memory is usually a high speed disk. It is known as the swap evice, an

Elaborate the memory devices - semiconductor memory, Elaborate the memory ...

Elaborate the memory devices  - Semiconductor memory All of the memory used as main store in a modern computer is applied as semiconductors fabricated on wafers of silicon. Sem

What is assembler, What is Assembler A macro-assembler or assembler nor...

What is Assembler A macro-assembler or assembler normally forms a part of operating system. That translates an assembly language program into machine language program.

What is an abstract data type (adt), What is an Abstract Data Type (ADT)? ...

What is an Abstract Data Type (ADT)? Abstract data types or ADTs are a mathematical specification of a set of data and the set of operations that can be done on the data. They

What are the limitations of mobile devices, What are the limitations of mob...

What are the limitations of mobile devices? For mobile devices we require both PC-integrated applications and specialized mobile services quite than repurposed website content.

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