NAME
i386_iopl
- change the i386 I/O privilege level
LIBRARY
i386 Architecture Library (libi386, -li386)
SYNOPSIS
int
i386_iopl(
int iopl
)
DESCRIPTION
i386_iopl(
)
sets the i386 I/O privilege level to the value specified by
iopl.
This call is restricted to the super-user.
RETURN VALUES
Upon successful completion,
i386_iopl(
)
returns 0.
Otherwise, a value of -1 is returned and the global
variable
errno
is set to indicate the error.
ERRORS
i386_iopl(
)
will fail if:
- [
EPERM
] -
The caller was not the super-user, or the operation was not permitted at the
current security level.
REFERENCES
i386 Microprocessor Programmer's Reference Manual, Intel
WARNING
You can really hose your machine if you enable user-level I/O and
write to hardware ports without care.