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

Find out the number of control lines for 32 to 1 multiplexer, The number of...

The number of control lines for 32 to 1 multiplexer is ? Ans. For 32 (2 5 ) the number of control lines and to select one i/p between them total 5 select lines are needed.

Structure of input - output interface, Q. Structure of Input - Output Inter...

Q. Structure of Input - Output Interface? Due to complexity and number of external devices that I/O interface control, there is not any standard structure of I/O interface. Let

Define the vbscript basics, VBScript is an easy and powerful to learn tool ...

VBScript is an easy and powerful to learn tool which can be used to add interaction to your Web pages. Web browser receives scripts along with rest of the Web document. Browser par

Operations of the web, Operations of the Web mainly depend on hypertext as ...

Operations of the Web mainly depend on hypertext as its means of interacting with users. But what is hypertext? Hypertext as such is the same as regular text that is it can be read

What is sap dispatcher, What is SAP dispatcher? SAP dispatcher is the co...

What is SAP dispatcher? SAP dispatcher is the control agent that handles the resources for the R/3 applications.

Explain r-2r ladder d/a converter, Explain R-2R ladder D/A converter. A...

Explain R-2R ladder D/A converter. Ans. R-2R ladder D/A converter: An R-2R ladder D/A converter is shown in Fig.(a). It uses resistors of only two values R and 2R. The inp

Convert the decimal to hexadecimal equivalent number, Convert the decimal n...

Convert the decimal number 45678 to its hexadecimal equivalent number. Ans: (45678) 10 =(B26E) 16 (45678) 10 =(B26E) 16

Using aspx view engine, When using aspx view engine, to have a steady look ...

When using aspx view engine, to have a steady look and feel, across all pages of the application, we can build use of asp.net master pages. What is asp.net master pages equal, when

What do you mean by u-area or u-block, What do you mean by u-area (user are...

What do you mean by u-area (user area) or u-block? This having the private data that is manipulated only by the Kernel. This is local to the Process, i.e. every process is a

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