[src/trunk]: src/sys/sys comment

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d788decc10c2
branches:  trunk
changeset: 770507:d788decc10c2
user:      yamt <yamt%NetBSD.org@localhost>
date:      Wed Oct 19 10:53:12 2011 +0000

description:
comment

diffstat:

 sys/sys/ioccom.h |  7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diffs (21 lines):

diff -r ae85e8bde728 -r d788decc10c2 sys/sys/ioccom.h
--- a/sys/sys/ioccom.h  Wed Oct 19 10:51:47 2011 +0000
+++ b/sys/sys/ioccom.h  Wed Oct 19 10:53:12 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ioccom.h,v 1.10 2009/05/19 21:59:10 christos Exp $     */
+/*     $NetBSD: ioccom.h,v 1.11 2011/10/19 10:53:12 yamt Exp $ */
 
 /*-
  * Copyright (c) 1982, 1986, 1990, 1993, 1994
@@ -38,6 +38,11 @@
  * Ioctl's have the command encoded in the lower word, and the size of
  * any in or out parameters in the upper word.  The high 3 bits of the
  * upper word are used to encode the in/out status of the parameter.
+ *
+ *      31 29 28                     16 15            8 7             0
+ *     +---------------------------------------------------------------+
+ *     | I/O | Parameter Length        | Command Group | Command       |
+ *     +---------------------------------------------------------------+
  */
 #define        IOCPARM_MASK    0x1fff          /* parameter length, at most 13 bits */
 #define        IOCPARM_SHIFT   16