plucky (2) inb_p.2.gz

NAME

       outb,  outw,  outl,  outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p,
       inw_p, inl_p - port I/O

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <sys/io.h>

       unsigned char inb(unsigned short port);
       unsigned char inb_p(unsigned short port);
       unsigned short inw(unsigned short port);
       unsigned short inw_p(unsigned short port);
       unsigned int inl(unsigned short port);
       unsigned int inl_p(unsigned short port);

       void outb(unsigned char value, unsigned short port);
       void outb_p(unsigned char value, unsigned short port);
       void outw(unsigned short value, unsigned short port);
       void outw_p(unsigned short value, unsigned short port);
       void outl(unsigned int value, unsigned short port);
       void outl_p(unsigned int value, unsigned short port);

       void insb(unsigned short port, void addr[.count],
                  unsigned long count);
       void insw(unsigned short port, void addr[.count],
                  unsigned long count);
       void insl(unsigned short port, void addr[.count],
                  unsigned long count);
       void outsb(unsigned short port, const void addr[.count],
                  unsigned long count);
       void outsw(unsigned short port, const void addr[.count],
                  unsigned long count);
       void outsl(unsigned short port, const void addr[.count],
                  unsigned long count);

DESCRIPTION

       This family of functions is used to do low-level port input and  output.   The  out*  functions  do  port
       output, the in* functions do port input; the b-suffix functions are byte-width and the w-suffix functions
       word-width; the _p-suffix functions pause until the I/O completes.

       They are primarily designed for internal kernel use, but can be used from user space.

       You must compile with -O or -O2 or similar.  The functions are defined as inline macros, and will not  be
       substituted in without optimization enabled, causing unresolved references at link time.

       You  use  ioperm(2)  or  alternatively  iopl(2) to tell the kernel to allow the user space application to
       access the I/O ports in  question.   Failure  to  do  this  will  cause  the  application  to  receive  a
       segmentation fault.

VERSIONS

       outb()  and  friends  are hardware-specific.  The value argument is passed first and the port argument is
       passed second, which is the opposite order from most DOS implementations.

STANDARDS

       None.

SEE ALSO

       ioperm(2), iopl(2)