Gain access to a port or memory-mapped device.
Synopsis:
uintptr_t startup_io_map(unsigned size, paddr_t phys)
Arguments:
- size
- The number of bytes of device I/O memory that you want to access. It may not
be 0.
- phys
- The physical address of the area that you want to access.
Description:
This function is used to gain access to a device or port:
- ARM
- Map a device's physical memory into a process's address space. This is the
same functionality as that provided by the
mmap_device_memory()
in the C library.
- x86
- Provide access to an I/O port. This is the same functionality as that
provided by as
mmap_device_io()
function in the C library.
Note: Use the value returned by
startup_io_map() while the startup
program is running. After startup has completed, use the value returned by
callout_io_map().
Returns:
The startup_io_map() function returns values like those returned
by the in*() and out*() functions in the C
library (see the
QNX
Neutrino C Library Reference).