Filter
Top Products
- 14 -
3.2 Service Call
How does the programmer use the kernel functions in a program?
First, it is necessary to call up kernel function from the program in some way or other. Calling a kernel function is referred
to as a service call. Task activation and other processing operations can be initiated by such a service call (See Figure 3.9).
Key input
Task
Kernel
Remote control
task
Service call Task switching
Figure 3.9 Service call
This service call is realized by a function call when the application program is written in C language, as shown below.
act_tsk(ID_main,3);
Furthermore, if the application program is written in assembly language, it is realized by an assembler macro call, as shown
below.
act_tsk #ID_main