1 files changed, 52 insertions, 0 deletions
diff --git a/board/sandbox/README.sandbox b/board/sandbox/README.sandbox
index c1f5f7e21f..9f5d3f71d5 100644
--- a/board/sandbox/README.sandbox
+++ b/board/sandbox/README.sandbox
@@ -190,6 +190,58 @@ Also sandbox uses generic board (CONFIG_SYS_GENERIC_BOARD) and supports
 driver model (CONFIG_DM) and associated commands.
 
 
+Linux RAW Networking Bridge
+---------------------------
+
+The sandbox_eth_raw driver bridges traffic between the bottom of the network
+stack and the RAW sockets API in Linux. This allows much of the U-Boot network
+functionality to be tested in sandbox against real network traffic.
+
+For Ethernet network adapters, the bridge utilizes the RAW AF_PACKET API.  This
+is needed to get access to the lowest level of the network stack in Linux. This
+means that all of the Ethernet frame is included. This allows the U-Boot network
+stack to be fully used. In other words, nothing about the Linux network stack is
+involved in forming the packets that end up on the wire. To receive the
+responses to packets sent from U-Boot the network interface has to be set to
+promiscuous mode so that the network card won't filter out packets not destined
+for its configured (on Linux) MAC address.
+
+The RAW sockets Ethernet API requires elevated privileges in Linux. You can
+either run as root, or you can add the capability needed like so:
+
+sudo /sbin/setcap "CAP_NET_RAW+ep" /path/to/u-boot
+
+The default device tree for sandbox includes an entry for eth0 on the sandbox
+host machine whose alias is "eth1". The following are a few examples of network
+operations being tested on the eth0 interface.
+
+sudo /path/to/u-boot -D
+
+DHCP
+....
+
+set autoload no
+set ethact eth1
+dhcp
+
+PING
+....
+
+set autoload no
+set ethact eth1
+dhcp
+ping $gatewayip
+
+TFTP
+....
+
+set autoload no
+set ethact eth1
+dhcp
+set serverip WWW.XXX.YYY.ZZZ
+tftpboot u-boot.bin
+
+
 SPI Emulation
 -------------