I386_IOPL(2) BSD Programmer's Manual (i386) I386_IOPL(2)NAMEi386_iopl - change the i386 I/O privilege level
SYNOPSIS
#include <sys/types.h>
#include <machine/sysarch.h>
int
i386_iopl(int iopl);
DESCRIPTIONi386_iopl() sets the i386 I/O privilege level to the value specified by
iopl. This call is restricted to the superuser.
Note: Code using the i386_iopl() function must be compiled using -li386.
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 er-
ror.
ERRORSi386_iopl() will fail if:
[EPERM] The caller was not the superuser.
SEE ALSOi386_get_ioperm(2), i386_set_ioperm(2)REFERENCES
Intel, i386 Microprocessor Programmer's Reference Manual.
WARNING
You can really hose your machine if you enable user-level I/O and write
to hardware ports without care.
MirOS BSD #10-current October 14, 1995 1