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

Demonstrate arc consistency, Demonstrate Arc consistency: To demonstra...

Demonstrate Arc consistency: To demonstrate the worth of performing an arc-consistency check before starting a serarch for a solution, we'll use an example from Barbara Smith'

Java, what is java?

what is java?

Avl tree rotation and b tree construction in data structure, Elements are g...

Elements are given 3,14,7,1,8,5,11,17,,6,23,12,20,26,4,16,18,24,25,19 We will construct b tree and avl tree And after that delete some integers

Define the character set of c language, Define the Character Set of C Langu...

Define the Character Set of C Language? C uses the lower case letter a to z, the upper case letters A to Z, the digits 0 to 9 and certain characters as building blocks to form

4 variable k-maps, 4-variable K-maps have 16 squares which arearranged in 4...

4-variable K-maps have 16 squares which arearranged in 4 columns and 4 rows.  Columns and rows are labeled with 2 variables. The rows are arranged so that C or D ch

The advantages of specifying parameters during instantiation, The advantage...

The advantages of specifying parameters during instantiation method are: -  All values to all the parameters do not need to be specified. Only those parameters that are assigne

Differences between flexgrid control and dbgrid control, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Smart card & e-cash, Smart Card & E-Cash E-cash storable smart cards ca...

Smart Card & E-Cash E-cash storable smart cards can kept and dispense cash electronically, making bills and coins lesser essential. It transfers funds over phone lines, making

Define the concept of typing of object oriented analysis, Define the concep...

Define the concept of Typing of object oriented analysis Typing enforces object class such that objects of different classes cannot be interchanged.  Or we can say that, class

E brokerage facilitates search & retrieval of information, E Brokerage faci...

E Brokerage facilitates search & retrieval of Information The success factor of a brokerage is its ability to retain existing clients and to enhance their satisfaction by effec

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