[U-Boot] [PATCH 3/3] Add the NBC + netconsole corresponding documentation

[tristan.lelong at blunderer.org]

From: Tristan Lelong <tristan.lelong at blunderer.org>


Signed-off-by: Tristan Lelong <tristan.lelong at blunderer.org>
---
 doc/README.netconsole |   66 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 66 insertions(+), 0 deletions(-)
 create mode 100644 doc/README.netconsole

diff --git a/doc/README.netconsole b/doc/README.netconsole
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+NETCONSOLE & NBC README
+
+# (C) Copyright 2010
+# Tristan Lelong, tristan.lelong at blunderer.org
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+
+Configuration Options:
+
+   CONFIG_NETCONSOLE
+      This enable the netconsole. Netconsole provide a remote access to 
+      u-boot command line thru udp stream.
+      basically, you just set some environment variables like:
+        - stdin, stdout, and stderr to "nc"
+        - ncip to <remote ip address>
+      and you can connect to the board ip, port 6666 (default) using 
+      "tools/netconsole <board ip addr>"
+
+   CONFIG_CMD_NBC
+      This enable the Net Boot Controller feature that will listen for 
+      NBC magic packet at boot time. If one of NBC packet is received, 
+      u-boot reconfigure itself automagically to use the netconsole
+      and interrupt the autoboot.
+      The NBC packet contains the new board IP and the remote ip.
+      It can also target special boards using filters on hostname and/or ethaddr
+      To broadcast NBC packets just use:
+      "tools/sendnbc -i <new board ip> [options]"
+      Two environment variable will allow to protect your board from receiving 
+      NBC interruptions:
+      	- nbcsource: only this remote IP can interrupt autoboot using NBC
+	- nbcinhibit: if this variable is present, NBC is fully inhibited
+
+
+NOTE:
+ NBC packet has the following format:
+
+One header
+ - NBC header (5 bytes):
+        - magical number 	1 byte		'0xD3'
+	- ASCII header 		3 bytes		"NBC"
+	- packet size		1 byte		'X'
+
+Several Data Chunks
+ - NBC data chunks (X-5 bytes)
+ 	- chunk name		4 bytes		"IP\0\0" | "MAC\0" | "HOST"
+	- chunk size		1 byte		'Y'
+	- chunk data		Y bytes		"xxxx"
+
+The IP chunk is mandatory, other are optional
+
-- 
1.7.2.3