funct(3rtapi)

NAME
rtapi_io.h - RTAPI wrappers for linux kernel functionality

SYNTAX

#include <rtapi_io.h>

unsigned char rtapi_inb(unsigned short int port);

unsigned short rtapi_inw(unsigned short int port);

unsigned int rtapi_inl(unsigned short int port);

unsigned void rtapi_outb(unsigned char value, unsigned short int port);

unsigned void rtapi_outw(unsigned short value, unsigned short int port);

unsigned void rtapi_inl(unsigned int value, unsigned short int port);

int rtapi_ioperm(unsigned long from, unsigned long num, int turn_on);

unsigned void rtapi_outl(unsigned int value, unsigned short int port);

DESCRIPTION
In kernel space, each rtapi_xxx or RTAPI_XXX identifier is mapped to the underlying kernel functionality, if available. In userspace, or in kernels where the underlying functionality is not provided by a kernel, generally another implementation--possibly with reduced functionality--is provided. (For example, the userspace implementation for rtapi_device_register and the kernel space implementation of rtapi_ioperm always succeeds)

REALTIME CONSIDERATIONS
Call from init/cleanup code and from realtime tasks. These functions will cause illegal instruction exceptions in userspace components, as well as in uspace rtapi_app when it is not setuid root.

RETURN VALUE
As in Linux.

SEE ALSO
inb(3), inw(3), inl(3), outb(3), outw(3), outl(3), ioperm(3),

AUTHOR
Jeff Epler