Chapter 2 - OS Structures Flashcards
What are some types of User Interfaces (UI)?
Command-Line Interfaces (CLI) or Graphics User Interface (GUI) or Batch
What to UIs do?
Allow the user to interact with the system services via system calls (typically written in C/C++)
What are five system services that are useful to the user?
1) Program Execution
2) I/O Operations
3) File-system Manipulation
4) Communications
5) Error detection
What are four system services that ensure efficient OS operation?
1) Resource allocation
2) Accounting
3) Protection
4) Security
What do Application Program Interfaces do?
Give access to most system calls through WIN32, POSIX, and Java
What does the system call interface do?
Maintain the number that is usually associated with each system call
How are parameters passed to the OS during a system call? (4 steps)
1) Pass the parameter in a register
2) Store parameter address in a block
3) Push onto the stack by program
4) Pop off stack by OS
What are some process control system calls? (9 total)
End, Abort, Load, Execute, Create/Terminate Process, Wait, Allocate/Free Memory
What are the five main categories of system calls?
1) Process control
2) File Management
3) Device Management
4) Information Maintenance
5) Communications
What are some device management system calls? (6 total)
Request/Release device, Read, Write, Logically Attach/Detach Devices
What are some file management system calls? (8 total)
Create/Delete File, Open/Close File, Read, Write, Get/Set Attributes
What are some information maintenance system calls? (10 total)
Get/Set Time, Get/Set System Data, Get/Set Process/File/Device Attributes
What is a OS layered approach?
When the OS is divided into a number of layers (levels), each built on top of lower layers. The bottom layer (level 0) is the hardware; the highest is the UI
What is modularity?
In a layered OS, when layers are selected such that each uses functions (operations) and services of only lower-level layers
