doc and binaries use root=/dev/nfs

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

binaries/wrboot-dhcp

@@ -22,7 +22,7 @@ bootargs="verbose console=ttyS0,115200 panic=10"
 
 # Pass IP information to the kernel (or ipinfo="dhcp" to re-request)
 ipinfo="$eth0.ipaddr:$eth0.serverip:$eth0.gateway:$eth0.netmask:wrs:eth0"
-bootargs="$bootargs root=nfs rw ip=$ipinfo"
+bootargs="$bootargs root=/dev/nfs rw ip=$ipinfo"
 
 # I you want, specify a non-default root directory
 bootargs="$bootargs nfsroot=/opt/root/wrs,tcp"

binaries/wrboot-static-ip

@@ -25,7 +25,7 @@ bootargs="verbose console=ttyS0,115200 panic=10"
 
 # Pass IP information to the kernel
 ipinfo="$eth0.ipaddr:$eth0.serverip:$eth0.gateway:255.255.255.0:wrs:eth0"
-bootargs="$bootargs root=nfs rw ip=$ipinfo"
+bootargs="$bootargs root=/dev/nfs rw ip=$ipinfo"
 
 # I you want, specify a non-default root directory
 bootargs="$bootargs nfsroot=/opt/root/wrs,tcp"

doc/wrs-developer-manual.in

@@ -914,7 +914,8 @@ the following command in a newly-created empty directory:
 
 To boot with NFS-root you should use a custom boot script,
 as described in the section @i{Using wrboot}, in the @i{@sc{wrs} User's
-Manual}.
+Manual}.  Please note that the kernel now needs @t{root=/dev/nfs},
+as the old convention @t{root=nfs} is not supported any more.
 
 The archives include a number of device special files in
 @i{dev}. The pre-created devices come from

doc/wrs-user-manual.in

@@ -1412,6 +1412,9 @@ The individual menu items perform the following actions:
 If you use the @i{wrboot} script option, you can for example run
 an NFS-Root system or do whatever customization and testing you want.
 
+@b{Note}: with 2.6.39 we suggested use of @t{root=nfs}, but this
+convention is no more supported in Linux, please use @t{root=/dev/nfs}.
+
 The complete filesystem after a successful build is called
 @t{images/wrs-image.tar.gz}, and is not included in the release
 firmware file, because an installed switch runs an @i{initramfs}
@@ -1491,10 +1494,18 @@ of known-working wrboot scripts as examples;
 @section Creating an NFS-Root Environment for WRS
 
 In order to create an NFS root directory, you should uncompress
-@t{wrs-image.tar.gz} that is created at build time.  If you use
+@t{wrs-image.tar.gz} that is created at build time in a newly-created
+empty directory:
+
+@example
+   tar xzf $WRS_OUTPUT_DIR/images/wrs-image.tar.gz
+@end example
+
+If you use
 a released @t{wrs-firmware.tar}, however, you'll have no overall
 filesystem for the switch, and you should rebuild it from two
-parts.  This is how to create your NFS filesystem (please adapt
+parts.  This is how to create your NFS filesystem from a
+released @t{wrs-firmware} file (please adapt
 for your local pathnames):
 
 @example