|Serial Line IP Implementation for Linux Kernel TCP/IP Stack|
|<<< Previous||Implementation Details||Next >>>| In the C
programming language the I/O space address can be accessed using
the functions inb() an outb(). The function declaration of inb()
and outb() is given below. char inb(char address); outb(char
pattern, char address); The function inb() reads a byte from the
address specified.The function outb() writes the pattern to the
address specified. Only super user can access this functions.
The user space needs a higher privilage level to gain access to
I/O space. This can be achieved using the function iopl(). The
declaration is given below. int iopl(int level); The call to
iopl() changes the input output privilage level to the level
specified. The program should be compiled with the -O option. O
stands for the optimization option. Before using UART it must be
properly initialized. The UART programming can be divided into
The first step in initializing the UART is setting the baud
rate. Data format reg