OUTB (2)
port output
inb, inw, inl, insb, insw, insl - port input
outb_p, outw_p, outl_p, inb_p, inw_p, inl_p - paused I/O
DESCRIPTION
This family of functions is used to do low level port input and output.
They are primarily designed for internal kernel use,
but can be used from user space, given the following information
in addition
to that given in
outb(9)
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. Failure 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 to most DOS implementations.
SEE ALSO
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