[IPV4]: Updates to nfsroot documentation

The difference between ip=off and ip=::::::off has been a cause of much
confusion.  Document how each behaves, and do not contradict ourselves by
saying that "off" is the default when in fact "any" is the default and is
descibed as being so lower in the file.

Signed-off-by: Amos Waterland <apw@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 3 deletions

diff --git a/Documentation/nfsroot.txt b/Documentation/nfsroot.txt
index 16a7cae2721d..9b956a969362 100644
--- a/Documentation/nfsroot.txt
+++ b/Documentation/nfsroot.txt
@@ -92,8 +92,14 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>
   autoconfiguration.
 
   The <autoconf> parameter can appear alone as the value to the `ip'
-  parameter (without all the ':' characters before) in which case auto-
-  configuration is used.
+  parameter (without all the ':' characters before).  If the value is
+  "ip=off" or "ip=none", no autoconfiguration will take place, otherwise
+  autoconfiguration will take place.  The most common way to use this
+  is "ip=dhcp".
+
+  Note that "ip=off" is not the same thing as "ip=::::::off", because in
+  the latter autoconfiguration will take place if any of DHCP, BOOTP or RARP
+  are compiled in the kernel.
 
   <client-ip>   IP address of the client.
 
@@ -142,7 +148,7 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>
                 into the kernel will be used, regardless of the value of
                 this option.
 
-                  off or none: don't use autoconfiguration (default)
+                  off or none: don't use autoconfiguration
                   on or any:   use any protocol available in the kernel
                   dhcp:        use DHCP
                   bootp:       use BOOTP