munmap_device_io()
QNX SDP8.0C Library ReferenceAPIDeveloper
Free access to a device's registers
Warning:
Use munmap() instead of
munmap_device_io(). The munmap_device_io() function
is a wrapper function for munmap() and is only provided for backwards
compatibility.
Synopsis:
#include <sys/mman.h>
int munmap_device_io( uintptr_t io,
size_t len );
Arguments:
- io
- The address of the area that you want to unmap.
- len
- The number of bytes of device I/O memory that you want to unmap.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The function munmap_device_io() unmaps len bytes of device I/O memory that's stored at io and was previously mapped with mmap_device_io().
Note:
On x86, this function does nothing and just returns 0.
It is only meaningful to call this function on ARM.
Returns:
- -1
- ARM only; an error occurred (errno is set).
- Any other value
- x86 only; 0 is always returned (see the note above).
Errors:
On ARM, this function may set any of the errors that munmap_flags() does.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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