[PATCH 08/11] doc: board: renesas: Document Retronix R-Car Gen4 V4H Sparrow Hawk board

[Marek Vasut]

Add document which clarifies how to build and install U-Boot on
Retronix R-Car Gen4 V4H Sparrow Hawk board.

Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
---
Cc: Nobuhiro Iwamatsu <iwamatsu at nigauri.org>
Cc: Tom Rini <trini at konsulko.com>
Cc: u-boot at lists.denx.de
---
 doc/board/renesas/index.rst                  |  1 +
 doc/board/renesas/rcar-gen4-sparrow-hawk.rst | 91 ++++++++++++++++++++
 doc/board/renesas/renesas.rst                |  2 +-
 3 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 doc/board/renesas/rcar-gen4-sparrow-hawk.rst

diff --git a/doc/board/renesas/index.rst b/doc/board/renesas/index.rst
index f04fd74cb17..68b11ebb455 100644
--- a/doc/board/renesas/index.rst
+++ b/doc/board/renesas/index.rst
@@ -18,4 +18,5 @@ Renesas
    rcar-gen3-install
    rcar-gen3-install-hf
    rcar-gen3-install-sf
+   rcar-gen4-sparrow-hawk
    rzn1
diff --git a/doc/board/renesas/rcar-gen4-sparrow-hawk.rst b/doc/board/renesas/rcar-gen4-sparrow-hawk.rst
new file mode 100644
index 00000000000..a1b92ecab57
--- /dev/null
+++ b/doc/board/renesas/rcar-gen4-sparrow-hawk.rst
@@ -0,0 +1,91 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Retronix R-Car Gen4 V4H Sparrow Hawk board
+==========================================
+
+- Retronix R-Car V4H Sparrow Hawk board: https://www.retronix.com.tw/en/product_sbc.html
+- Retronix R-Car V4H Sparrow Hawk documenation: https://rcar-community.github.io/Sparrow-Hawk/index.html
+
+Build U-Boot
+------------
+
+Please follow :doc:`Renesas 64-bit ARM SoC build environment setup <build-env-aarch64>`
+to correctly set up the build environment before attempting to build U-Boot.
+
+Clone up to date U-Boot source code and change directory into the
+newly cloned source directory:
+
+.. code-block:: console
+
+    $ git clone https://source.denx.de/u-boot/u-boot.git/
+    $ cd u-boot
+
+Configure U-Boot:
+
+.. code-block:: console
+
+    $ make r8a779g3_sparrowhawk_defconfig
+
+Compile U-Boot:
+
+.. code-block:: console
+
+    $ make
+
+To speed up build process, -jN option can be passed to make to start
+multiple jobs at the same time, this is beneficial especially on SMP
+systems. The following example starts up to number of CPUs in the
+system jobs, which is the recommended amount:
+
+.. code-block:: console
+
+    $ make -j$(nproc)
+
+Install U-Boot
+--------------
+
+In order to install U-Boot using write into SPI NOR, first build U-Boot
+for this target and collect ``flash.bin`` build artifact. Then start the
+target, drop into U-Boot shell, and load the build artifact into DRAM at
+well known address:
+
+.. code-block:: console
+
+    => tftp 0x50000000 flash.bin
+
+Finally, write U-Boot into SPI NOR:
+
+.. code-block:: console
+
+    => sf probe && sf update 0x50000000 0 ${filesize}
+
+Bundle TFA BL31 into Linux kernel fitImage
+------------------------------------------
+
+The Retronix R-Car V4H Sparrow Hawk board starts both TFA BL31 and Linux
+kernel from U-Boot. Both TFA BL31, Linux kernel and DT blob have to be
+bundled into the fitImage.
+
+Perform the following steps to build TFA at least v2.14.y:
+
+.. code-block:: console
+
+    $ git clone https://github.com/ARM-software/arm-trusted-firmware.git
+    $ cd arm-trusted-firmware
+    $ make -j$(nproc) bl31 \
+        PLAT=rcar_gen4 ARCH=aarch64 LSI=V4H SPD=none \
+        CTX_INCLUDE_AARCH32_REGS=0 MBEDTLS_COMMON_MK=1 \
+        PTP_NONSECURE_ACCESS=1 LOG_LEVEL=20 DEBUG=0 \
+        ENABLE_ASSERTIONS=0
+
+The bundling is done using U-Boot ``mkimage`` tool:
+
+.. code-block:: console
+
+    mkimage \
+        -f auto -E -A arm64 -C none -e 0x50200000 -a 0x50200000 \
+        -d /path/to/linux/arch/arm64/boot/Image \
+        -b /path/to/linux/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dtb \
+        -y /path/to/arm-trusted-firmware/build/rcar_gen4/*/bl31.bin \
+        -Y 0x46400000 \
+        /path/to/output/fitImage
diff --git a/doc/board/renesas/renesas.rst b/doc/board/renesas/renesas.rst
index 6aaf1b13f29..234094a4259 100644
--- a/doc/board/renesas/renesas.rst
+++ b/doc/board/renesas/renesas.rst
@@ -187,7 +187,7 @@ Renesas is a SoC solutions provider for automotive and industrial applications.
      - r8a779g0_whitehawk_defconfig
 
    * -
-     - Sparrow Hawk
+     - :doc:`Sparrow Hawk <rcar-gen4-sparrow-hawk>`
      - R8A779G3 (V4H)
      - :doc:`arm64 <build-env-aarch64>`
      - r8a779g3_sparrowhawk_defconfig
-- 
2.53.0