System calls allow programs to request services from the operating system kernel. They are generally implemented as assembly instructions and can be invoked from C/C++. Parameters can be passed via registers, memory blocks, or pushing to the stack. System calls are categorized as process control, file management, device management, information maintenance, and communication. Examples provided include creating and terminating processes, opening and closing files, reading/writing devices, getting time/date, and sending/receiving messages.

1. University of Development
Alternative
Presentation Topic : System Call
Presented By
MD.Shahadat Hossain (011161060)
MD.Jakaria Masud (011161028)
MD.Shuvo Chowdhury (011161056)

2. System Call
 The mechanism used by an application program
requests a service from the kernel of the operating
system.
• These calls are generally available as Assembly
language instruction.
• UNIX System calls can be invoked directly from a C or
C++ program.

5. Methods of Passing Parameters to Operating
System
 The simplest is approach is to pass
parameter through registers.
• The second is by storing parameters in blocks and
passing the address through registers
• Finally parameter can be pushed into stack by the
program and popped of by the Operating System.

8. Categories of System Calls
System calls can be grouped into five major
categories as follows.
• Process control
• File management.
• Device management
• Information Maintenance and
• Communication.

9. Processcontrol
Some system calls under process control are:
 End, abort
 Load, execute
 Create process, terminate process
 Get process, terminate process
 Wait for time
 Allocate and free memory

10. File management.
Some system calls under file management are:
 Create file, delete file
 Open , close
 Read, write, reposition.
 Get file attributes, set fil attributes

11. Device management
Some system calls under device management are:
 Request Device, release device
 Read, write, reposition.
 Get device attributes and set device attributes
 Logically attach or detach devices

12. Information Maintenance
Some system calls under information maintenance are:
 Get time or date, Set time of date
 Logically attach or detach devices
 Information maintenance
 Get system data, Set Systems data
 Get process, file of device attributes
 Set process, file or device attributes

13. Communication
 Create, delete communication connection.
 Send, receive messages
 Transfer status information
 Attach or detach remote devices.

14. Thank You