[PATCH v4 3/3] doc: board: starfive: Add Xunlong OrangePi RV

[E Shattow <e@freeshell.de>]

OrangePi RV is a board that uses the same EEPROM product serial identifier
as the StarFive VisionFive 2 1.3b.

In fact it is not completely compatible with the StarFive VisionFive 2
1.3b for use with Linux Kernel however it is good enough for use with
U-Boot SPL and U-Boot Main. Describe how to set the devicetree search path
and, for advanced users, suggest that it is possible to update the EEPROM
data with an invented "XOPIRV" identifier for automatic board detection.

Signed-off-by: E Shattow <e@freeshell.de>
---
 doc/board/starfive/index.rst       |  1 +
 doc/board/starfive/orangepi_rv.rst | 35 ++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 doc/board/starfive/orangepi_rv.rst

diff --git a/doc/board/starfive/index.rst b/doc/board/starfive/index.rst
index f85d7376b44..0996e0a68aa 100644
--- a/doc/board/starfive/index.rst
+++ b/doc/board/starfive/index.rst
@@ -10,5 +10,6 @@ StarFive
    milk-v_mars
    milkv_marscm_emmc
    milkv_marscm_lite
+   orangepi_rv
    pine64_star64
    visionfive2
diff --git a/doc/board/starfive/orangepi_rv.rst b/doc/board/starfive/orangepi_rv.rst
new file mode 100644
index 00000000000..29cc58a1e2b
--- /dev/null
+++ b/doc/board/starfive/orangepi_rv.rst
@@ -0,0 +1,35 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Xunlong OrangePi RV
+===================
+
+U-Boot for the OrangePi RV uses the same U-Boot binaries as the VisionFive 2
+board. In U-Boot SPL the actual board is detected as a VisionFive2 1.3b due to
+a manufacturer problem and having the same EEPROM data as VisionFive2 1.3b.
+
+Device-tree selection
+---------------------
+
+U-Boot will set variable $fdtfile to starfive/jh7110-starfive-visionfive-2-v1.3b.dtb
+
+This is sufficient for U-Boot however fails to work correctly with the Linux Kernel.
+
+To overrule this selection the variable can be set manually and saved in the
+environment
+
+::
+
+    env set fdtfile starfive/jh7110-orangepi-rv.dtb
+    env save
+
+EEPROM modification
+-------------------
+
+For advanced users and developers an EEPROM identifier product serial number
+beginning with "XOPIRV" will match the OrangePi RV and automatically set the
+correct device-tree at U-Boot SPL phase. The procedure for writing EEPROM data
+is not detailed here however is similar to that of the Pine64 Star64 and Milk-V
+Mars CM. The write-protect disable pads on the Orange Pi RV circuit board
+bottom are labeled WP and GND near the M.2 connector.
+
+.. include:: jh7110_common.rst
-- 
2.50.0