in8()
QNX SDP8.0C Library ReferenceAPIDeveloper
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.
Note:
The in*() and out*() functions are for accessing legacy
devices on x86_64 systems that still use legacy I/O-addressed I/O ports, and should not be used in any
other context.
The process must have the PROCMGR_AID_IO ability enabled, and the calling thread must have I/O privileges, or else it will fault with a SIGSEGV; see procmgr_ability(), and the ThreadCtl() _NTO_TCTL_IO_LEVEL command.
Returns:
An 8-bit value.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Signal handler | Yes |
Thread | Yes |
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