Updated: April 19, 2023 |
Read a 16-bit value from a port
#include <hw/inout.h> uint16_t in16( uintptr_t port ); #define inbe16 ( port ) ... #define inle16 ( port ) ...
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The in16() function reads a 16-bit value from the specified port in native-endian format (there's no conversion required).
The inbe16() and inle16() macros read a 16-bit value that's in big-endian or little-endian format, respectively, from the specified port, and returns the value as native-endian.
The calling process must use mmap_device_io() to access the device's I/O registers.
On x86_64 targets, 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.
A 16-bit value in native-endian.
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | Yes |
Signal handler | Yes |
Thread | Yes |
Both inbe16() and inle16() are implemented as macros.