HP-UX 11i Version 2 Release Notes (October 2003)

Commands and System Calls
The mmap() Function
Chapter 8
197
• Benefits of the -e option:
You will be able to visually map the firmware representation of the device (EFI path)
to its HP-UX representation. This should aid in a multi-OS environment where the
other OSes understand the EFI but don't understand the HP-UX path.
Compatibility
There are no compatibility issues.
Performance
The new options will not affect performance of the ioscan command.
Documentation
The ioscan (1M) manpage and the ioscan usage message have been enhanced to provide
information about these new options.
Obsolescence
Not applicable.
The mmap() Function
The mmap() function establishes a mapping between a process's address space and a file.
Summary of Change
By using the new MAP_IO flag, you may now use the mmap() function to establish a
mapping between a process's address space and I/O device registers or memory. This
functionality allows user programs to set up DMA or RDMA functionality and other I/O
mechanisms without the overhead of going through a kernel driver. The MAP_IO
functionality will be limited to superusers and processes running in Real Time
Extensions processor sets.
This interface is a requirement for HP-UX Real Time Extensions functionality.
See also “ccNUMA” on page 246 for other changes to mmap().
Impact
It is now possible to perform mappings between a process's address space and I/O device
registers or memory.
No existing functionality of mmap is modified by this extension. Customers not using
MAP_IO will not be impacted.
Compatibility
There are no compatibility issues. This new flag does not affect existing users of mmap().