[PATCH v7 21/22] doc: sifive: fu540: Add description for OpenSBI generic platform

[Pragnesh Patel]

OpenSBI generic platform support provides platform specific
functionality based on the FDT passed by previous booting stage.

depends on OpenSBI commit:
platform: Add generic FDT based platform support
(sha1: f1aa9e54e00006ae70aeac638d5b75093520f65d)

Signed-off-by: Pragnesh Patel <pragnesh.patel at sifive.com>
---
 doc/board/sifive/fu540.rst | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/doc/board/sifive/fu540.rst b/doc/board/sifive/fu540.rst
index 610ba87074..1c3d4740f3 100644
--- a/doc/board/sifive/fu540.rst
+++ b/doc/board/sifive/fu540.rst
@@ -22,14 +22,21 @@ The support for following drivers are already enabled:
 
 TODO:
 
-1. U-Boot expects the serial console device entry to be present under /chosen
-   DT node. Without a serial console U-Boot will panic. Example:
+1. The DTB passed by U-Boot SPL or FSBL to OpenSBI should have CLINT
+   DT node and the "/chosen" DT node should have "stdout-path" DT
+   property.
 
 .. code-block:: none
 
-   chosen {
-        stdout-path = "/soc/serial at 10010000:115200";
-   };
+	chosen {
+		stdout-path = "/soc/serial at 10010000:115200";
+	};
+
+	clint at 2000000 {
+		compatible = "riscv,clint0";
+		interrupts-extended = <&cpu0_intc 3 &cpu0_intc 7 &cpu1_intc 3 &cpu1_intc 7 &cpu2_intc 3 &cpu2_intc 7 &cpu3_intc 3 &cpu3_intc 7 &cpu4_intc 3 &cpu4_intc 7>;
+		reg = <0x0 0x2000000 0x0 0xc0000>;
+	};
 
 Building
 --------
@@ -58,7 +65,7 @@ firmware. We need to compile OpenSBI with below command:
 
 .. code-block:: none
 
-make PLATFORM=sifive/fu540 FW_PAYLOAD_PATH=<path to u-boot-dtb.bin>
+	make PLATFORM=generic FW_PAYLOAD_PATH=<path to u-boot-dtb.bin>
 
 More detailed description of steps required to build FW_PAYLOAD firmware
 is beyond the scope of this document. Please refer OpenSBI documenation.
-- 
2.17.1