NAME
io —
I/O privilege file
DESCRIPTION
This device is obsolete and is provided for compatibility
purposes only; use
i386_iopl(2) instead.
After opening /dev/io for writing the process is granted full I/O privileges; closing the returned file descriptor does not result in revocation of these privileges. The new I/O privileges can be useful in order to write userland programs that handle some hardware directly.
The entire access control is handled by the file access permissions of /dev/io, so care should be taken in granting rights for this device.
I/O privilege on access to /dev/io is only
granted if the kernel was built with the COMPAT_10
option.
FILES
- /dev/io
SEE ALSO
HISTORY
The io file appeared in
NetBSD 1.0 after it was in the kernel for some
time.