Add documentation for Ariane FPGA platform

Signed-off-by: Panagiotis Peristerakis <perister@ics.forth.gr>

docs/platform/ariane-fpga.md

@@ -0,0 +1,37 @@
+Ariane FPGA SoC Platform
+==========================
+Ariane is a 6-stage, single issue, in-order CPU which implements the 64-bit RISC-V instruction set.
+The Ariane FPGA development platform is based on FPGA FPGA SoC(which currently supports only  Genesys 2 board) and is capable
+of running Linux.
+ The FPGA SoC currently contains the following peripherals:
+- DDR3 memory controller
+- SPI controller to conncet to an SDCard
+- Ethernet controller
+- JTAG port (see debugging section below)
+- Bootrom containing zero stage bootloader and device tree.
+
+To build platform specific library and firmwares, provide the
+*PLATFORM=ariane-fpga* parameter to the top level `make` command.
+
+Platform Options
+----------------
+
+The *Ariane FPGA* platform does not have any platform-specific
+options.
+
+Building Ariane FPGA Platform
+-----------------------------
+**Linux Kernel Payload**
+
+
+```
+make PLATFORM=ariane-fpga FW_PAYLOAD_PATH=<linux_build_directory>/arch/riscv/boot/Image
+```
+
+Booting Ariane FPGA Platform
+-----------------------------
+
+**Linux Kernel Payload**
+
+As Linux kernel image is embedded in the OpenSBI firmware binary, Ariane will directly
+boot into Linux directly after powered on.

docs/platform/platform.md

@@ -21,6 +21,9 @@ OpenSBI currently supports the following virtual and hardware platforms:
 * **Kendryte K210 SoC**: Platform support for the Kendryte K210 SoC used on
   boards such as the Kendryte KD233 or the Sipeed MAIX Dock.
 
+* **Ariane FPGA SoC**: Platform support for the Ariane FPGA SoC used on
+  Genesys 2 board.
+
 The code for these supported platforms can be used as example to implement
 support for other platforms. The *platform/template* directory also provides
 template files for implementing support for a new platform. The *object.mk*,
@@ -30,3 +33,4 @@ facilitate the implementation.
 [qemu_virt.md]: qemu_virt.md
 [qemu_sifive_u.md]: qemu_sifive_u.md
 [sifive_fu540.md]: sifive_fu540.md
+[ariane-fpga.md]: ariane-fpga.md