in32(), inbe32(), inle32()
Read a 32-bit value from a port
Synopsis:
#include <hw/inout.h> uint32_t in32( uintptr_t port ); #define inbe32 ( port ) ... #define inle32 ( 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 in32() function reads a 32-bit value from the specified port.
The inbe32() and inle32() macros read a 32-bit value that's in big-endian or little-endian format, respectively, from the specified port, and returns the value as native-endian.
Returns:
A 32-bit value in native-endian.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | Yes |
Signal handler | Yes |
Thread | Yes |
Caveats:
The calling thread must have the PROCMGR_AID_IO ability enabled and must have I/O privileges; see procmgr_ability() , and ThreadCtl() 's _NTO_TCTL_IO command for details.
The calling process must also use mmap_device_io() to access the device's I/O registers.
Both inbe32() and inle32() are implemented as macros.