[apple/xnu.git] / osfmk / man / i386_io_port_add.html

<h2>i386_io_port_add</h2>\r<hr>\r<p>\r<strong>Function</strong> - Permit target thread to invoke operations on the specified device.\r<h3>SYNOPSIS</h3>\r<pre>\r<strong>kern_return_t   i386_io_port_add</strong>\r                <strong>(thread_act_t</strong>                        <var>target_act</var>,\r                 <strong>device_t</strong>                                <var>device</var><strong>);</strong>\r</pre>\r<h3>PARAMETERS</h3>\r<dl>\r<p>\r<dt> <var>target_act</var> \r<dd>\r[in thread send right]\rThread whose permission bitmap is to be set.\r<p>\r<dt> <var>device</var> \r<dd>\r[in device send right]\rThe device to which I/O instructions are to be\rpermitted.\r</dl>\r<h3>DESCRIPTION</h3>\r<p>\rThe <strong>i386_io_port_add</strong> function adds a device to the\rI/O permission bitmap for a \rthread, thereby permitting the thread to execute I/O instructions against the\rdevice.\r<h3>NOTES</h3>\r<p>\rNormally, the thread must have called <strong>i386_io_port_add</strong> \rfor all devices to which it will execute I/O instructions.  However, possessing\rsend rights to the <var>iopl</var> device port will cause the \r<var>iopl</var> device to be automatically added to the \rthread's I/O map upon first attempted access.  This is a backward\rcompatibility feature for the DOS emulator.\r<h3>RETURN VALUES</h3>\r<p>\rOnly generic errors apply.\r<h3>RELATED INFORMATION</h3>\r<p>\rFunctions:\r<a href="i386_io_port_list.html"><strong>i386_io_port_list<strong></a>,\r<a href="i386_io_port_remove.html"><strong>i386_io_port_remove<strong></a>.\r