Documentation: migrate "SLIP Configuration" from wiki

link: https://cwiki.apache.org/confluence/display/NUTTX/SLIP+Configuration

Documentation/components/net/index.rst

@@ -8,6 +8,7 @@ Network Support
   sixlowpan.rst
   socketcan.rst
   netguardsize.rst
+  slip.rst
 
 ``net`` Directory Structure ::
 

Documentation/components/net/slip.rst

@@ -0,0 +1,50 @@
+====
+SLIP
+====
+
+SLIP Configuration
+==================
+
+#. Configure and build NuttX with SLIP enabled in the configuration. Load this
+   into FLASH and start the device.
+
+#. Connect to a Linux box using a serial cable. This dicussion assumes that the
+   serial device is ``/dev/ttyS0`` on both the target and the Linux box.
+
+#. Reset on the target side and attach SLIP on the Linux side:
+
+   .. code-block:: bash
+
+      $ modprobe slip
+      $ slattach -L -p slip -s 57600 /dev/ttyS0 &
+
+   This should create an interface with a name like sl0, or sl1, etc. Add -d to
+   get debug output. This will show the interface name.
+
+   NOTE: The -L option is included to suppress use of hardware flow control.
+   This is necessary only if you are not supporting hardware flow control on
+   the target.
+
+   NOTE: The Linux slip module hard-codes its MTU size to 296. So you might
+   as well set ``CONFIG_NET_ETH_MTU`` to 296 as well.
+
+#. After turning over the line to the SLIP driver, you must configure the
+   network interface. Again, you do this using the standard ifconfig and
+   route commands. Assume that we have connected to a host PC with address
+   192.168.0.101 from your target with address 10.0.0.2. On the Linux PC
+   you would execute the following as root (assuming the SLIP is attached
+   to device sl0):
+
+   .. code-block:: bash
+
+      $ ifconfig sl0 10.0.0.1 pointopoint 10.0.0.2 up
+      $ route add 10.0.0.2 dev sl0
+
+#. For monitoring/debugging traffic:
+
+   .. code-block:: bash
+
+      $ tcpdump -n -nn -i sl0 -x -X -s 1500
+
+   NOTE: If hardware handshake is not available, then you might try the
+   slattach option-L which is supposed to enable "3-wire operation."