i386_io_port_add

Function - Permit target thread to invoke operations on the specified device.

SYNOPSIS

kern_return_t   i386_io_port_add
                (thread_act_t                        target_act,
                 device_t                                device);

PARAMETERS

target_act

[in thread send right] Thread whose permission bitmap is to be set.

device

[in device send right] The device to which I/O instructions are to be permitted.

DESCRIPTION

The i386_io_port_add function adds a device to the I/O permission bitmap for a thread, thereby permitting the thread to execute I/O instructions against the device.

NOTES

Normally, the thread must have called i386_io_port_add for all devices to which it will execute I/O instructions. However, possessing send rights to the iopl device port will cause the iopl device to be automatically added to the thread's I/O map upon first attempted access. This is a backward compatibility feature for the DOS emulator.

RETURN VALUES

Only generic errors apply.

RELATED INFORMATION

Functions: i386_io_port_list, i386_io_port_remove.