doc: boards: amlogic: update documentation for NanoPi-K2

Improve documentation. Notably we can now support U-Boot install to
the removable eMMC storage module in addition to SD cards.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Link: https://lore.kernel.org/r/20230320114609.930145-15-christianshewitt@gmail.com
[narmstrong: fixed doc build]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

doc/board/amlogic/nanopi-k2.rst

@@ -1,10 +1,10 @@
 .. SPDX-License-Identifier: GPL-2.0+
 
-U-Boot for NanoPi-K2
+U-Boot for NanoPi-K2 (S905)
-====================
+===========================
 
-NanoPi-K2 is a single board computer manufactured by FriendlyElec
+NanoPi-K2 is a single board computer manufactured by FriendlyElec with the following
-with the following specifications:
+specifications:
 
  - Amlogic S905 ARM Cortex-A53 quad-core SoC @ 1.5GHz
  - ARM Mali 450 GPU
@@ -18,7 +18,7 @@ with the following specifications:
 
 Schematics are available on the manufacturer website.
 
-U-Boot compilation
+U-Boot Compilation
 ------------------
 
 .. code-block:: bash
@@ -27,14 +27,21 @@ U-Boot compilation
     $ make nanopi-k2_defconfig
     $ make
 
-Image creation
+U-Boot Signing with Pre-Built FIP repo
---------------
+--------------------------------------
 
-For simplified usage, pleaser refer to :doc:`pre-generated-fip` with codename `nanopi-k2`
+.. code-block:: bash
 
-Amlogic doesn't provide sources for the firmware and for tools needed
+    $ git clone https://github.com/LibreELEC/amlogic-boot-fip --depth=1
-to create the bootloader image, so it is necessary to obtain them from
+    $ cd amlogic-boot-fip
-the git tree published by the board vendor:
+    $ mkdir my-output-dir
+    $ ./build-fip.sh nanopi-k2 /path/to/u-boot/u-boot.bin my-output-dir
+
+U-Boot Manual Signing
+---------------------
+
+Amlogic does not provide sources for the firmware and tools needed to create a bootloader
+image so it is necessary to obtain binaries from sources published by the board vendor:
 
 .. code-block:: bash
 
@@ -43,7 +50,6 @@ the git tree published by the board vendor:
     $ tar xvfJ gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz
     $ tar xvfJ gcc-linaro-arm-none-eabi-4.8-2013.11_linux.tar.xz
     $ export PATH=$PWD/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin:$PWD/gcc-linaro-arm-none-eabi-4.8-2013.11_linux/bin:$PATH
-    $ git clone https://github.com/BayLibre/u-boot.git -b libretech-cc amlogic-u-boot
     $ git clone https://github.com/friendlyarm/u-boot.git -b nanopi-k2-v2015.01 amlogic-u-boot
     $ cd amlogic-u-boot
     $ sed -i 's/aarch64-linux-gnu-/aarch64-none-elf-/' Makefile
@@ -52,7 +58,7 @@ the git tree published by the board vendor:
     $ make
     $ export FIPDIR=$PWD/fip
 
-Go back to mainline U-Boot source tree then :
+Go back to the mainline U-Boot source tree then:
 
 .. code-block:: bash
 
@@ -65,6 +71,10 @@ Go back to mainline U-Boot source tree then :
     $ cp $FIPDIR/gxb/bl301.bin fip/
     $ cp $FIPDIR/gxb/bl31.img fip/
     $ cp u-boot.bin fip/bl33.bin
+    $ wget https://github.com/LibreELEC/amlogic-boot-fip/raw/master/nanopi-k2/bl1.bin.hardkernel fip/bl1.bin.hardkernel
+    $ chmod +x fip/bl1.bin.hardkernel
+    $ wget https://github.com/LibreELEC/amlogic-boot-fip/raw/master/nanopi-k2/aml_chksum fip/aml_chksum
+    $ chmod +x fip/aml_chksum
 
     $ $FIPDIR/blx_fix.sh \
               fip/bl30.bin \
@@ -75,12 +85,12 @@ Go back to mainline U-Boot source tree then :
               fip/bl30_new.bin \
               bl30
 
-    $ $FIPDIR/fip_create \
+    $ $FIPDIR/fip_create --bl30 fip/bl30_new.bin \
-    	 --bl30 fip/bl30_new.bin \
                          --bl31 fip/bl31.img \
                          --bl33 fip/bl33.bin \
                          fip/fip.bin
 
+    $ sed -i 's/\x73\x02\x08\x91/\x1F\x20\x03\xD5/' fip/bl2.bin
     $ python $FIPDIR/acs_tool.pyc fip/bl2.bin fip/bl2_acs.bin fip/acs.bin 0
 
     $ $FIPDIR/blx_fix.sh \
@@ -98,9 +108,15 @@ Go back to mainline U-Boot source tree then :
                                   --input fip/boot_new.bin
                                   --output fip/u-boot.bin
 
-and then write the image to SD with:
+Then write U-Boot to SD or eMMC with:
 
 .. code-block:: bash
 
-    $ DEV=/dev/your_sd_device
+    $ DEV=/dev/boot_device
-    $ dd if=fip/u-boot.bin of=$DEV conv=fsync,notrunc bs=512 seek=1
+    $ dd if=fip/u-boot.bin of=fip/u-boot.bin.gxbb bs=512 conv=fsync
+    $ dd if=fip/u-boot.bin of=fip/u-boot.bin.gxbb bs=512 seek=9 skip=8 count=87 conv=fsync,notrunc
+    $ dd if=/dev/zero of=fip/u-boot.bin.gxbb bs=512 seek=8 count=1 conv=fsync,notrunc
+    $ dd if=bl1.bin.hardkernel of=fip/u-boot.bin.gxbb bs=512 seek=2 skip=2 count=1 conv=fsync,notrunc
+    $ ./aml_chksum fip/u-boot.bin.gxbb
+    $ dd if=fip/u-boot.gxbb of=$DEV conv=fsync,notrunc bs=512 skip=1 seek=1
+    $ dd if=fip/u-boot.gxbb of=$DEV conv=fsync,notrunc bs=1 count=440