feat(fb2cdg1-doc): add Initial Boot instruction section

Author: David Benes

cards/silicom/fb2cdg1/readme.rst

@@ -46,3 +46,51 @@ The correct variant for the firmware build can be selected using the Makefile pa
 
 - ``BOARD_VARIANT=1`` - The board uses FPGA part number ``AGMF039R47A1E2VC`` (Production sample).
 - ``BOARD_VARIANT=0`` - The board uses FPGA part number ``AGMF039R47A2E2VR0`` (Engineering sample).
+
+Initial Boot instructions
+^^^^^^^^^^^^^^^^^^^^^^^^^
+The card itself should be preloaded with firmware designed by Silicom.
+This design can be used to load an FPGA image to the BMC flash via PCIe using the Silicom ``rawcardtool`` tool.
+
+**Execute the following steps to perform the manual initialization:**
+
+    1. Obtain PCIe address of the card by the command below. In this example, the PCIe address is ``01:00.0`` and will be used in the next steps:
+
+        .. code::
+
+            $ lspci | grep "Silicom Denmark Device"
+            01:00.0 Ethernet controller: Silicom Denmark Device 0001
+    2. Ensure the card respond to memory space accesses by command:
+
+        .. code::
+
+            $ setpci -s 01:00.0 COMMAND=0x0002
+    3. Flash the ``fpga_page1_pacsign_user1.bin`` file to the card using RawCardTool provided by Silicom:
+
+        .. code::
+
+            $ rawcardtool_fjord --device 01:00.0 --flash fpga_page1_pacsign_user1.bin
+    4. Set your design as default by command:
+
+        .. code::
+
+            $ rawcardtool_fjord --device 01:00.0 --fpgadefault user1
+    5. Boot your design executing:
+
+        .. code::
+
+            $ rawcardtool_fjord --device 01:00.0 --reboot-fpga user1
+
+.. note::
+
+    The ``fpga_page1_pacsign_user1.bin`` file will be located in the build folder of your application after building. For NDK-FPGA, the folder is ``ndk-fpga/apps/minimal/build/fb2cdg1``.
+
+.. note::
+
+    If some bars are unmapped, power cycle the server.
+
+If the ``rawcardtool`` tool is unavailable, it is possible to use JTAG to load the design (SOF file), and ``nfb-boot`` command to load the BMC flash with the FPGA image:
+
+    .. code::
+
+        $ nfb-boot -f0 fb2cdg1-minimal-pcie1xgen5x8x8-400g2.nfw