Memory and File Protection
Date on which it was created: Created: February 2,
2004
Date on which it was last-updated:Last Updated: February 2,
2004
Sub Module version number: Version 0.1
Author of the sub module: Dr. Ping Chen
Code: OSS2
Objectives
This submodule covers memory and file protection mechanism
in an operating system.
Prerequisite
OSS1
Description
This submodule discusses
techniques used for memory and address protection and file protection. Memory
and address protection can be built into the hardware mechanisms, such as fence,
relocation, base/bounds registers, tagged architecture, segmentation, paging.
File protection means include all-none protection, group protection, single
permissions and temporary acquired permission.
Lecture Notes
Notes
1
Assignments
Assignment
1
Assignment
2
Assignment
3
Resources
Books
Articles
Links
Glossary
Memory hierarchy: A typical computer has several different
levels of storage. Each level of storage has a different speed, cost, and size.
The levels form a storage hierarchy, in which the topmost levels (those nearest
the processor) are fastest, most expensive and smallest.
Memory protection: Many operating systems support protection
of memory pages. Individual pages may be protected against a combination of
read, write or execute accesses by a process.
Distributed file system: A distributed file system is a
client/server-based application that allows clients to access and process data
stored on the server as if it were on their own computer. When a user accesses a
file on the server, the server sends the user a copy of the file, which is
cached on the user's computer while the data is being processed and is then
returned to the server.