in8()

Read an 8-bit value from a port

Synopsis:

#include <hw/inout.h>

uint8_t in8( uintptr_t port );

Arguments:

port
The port you want to read the value from.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The in8() function reads an 8-bit value from the specified port.

The calling process must use mmap_device_io() to access the device's I/O registers.

On x86 targets, the calling thread must have I/O privileges, or else it will fault with a SIGSEGV; see the ThreadCtl() _NTO_TCTL_IO command for details.

Returns:

An 8-bit value.

Classification:

QNX Neutrino

Safety:
Cancellation point No
Interrupt handler Yes
Signal handler Yes
Thread Yes

See also:

in8s(), in16(), in16s(), in32(), in32s(), mmap_device_io(), out8(), out8s(), out16(), out16s(), out32(), out32s()