inl

OUTB(2)			  Linux Programmer’s Manual		      OUTB(2)



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


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

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

       You  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.	Fail-
       ure  to	do  this will cause the application to receive a segmentation
       fault.


CONFORMING TO
       outb and friends are hardware specific. The port and  value  arguments
       are in the opposite order from most DOS implementations.

SEE ALSO
       ioperm(2), iopl(2)



Linux				  1995-11-29			      OUTB(2)