.. SPDX-License-Identifier: GPL-2.0+

U-Boot for NanoPi-K2 (S905)
===========================

NanoPi-K2 is a single board computer manufactured by FriendlyElec with the following
specifications:

 - Amlogic S905 ARM Cortex-A53 quad-core SoC @ 1.5GHz
 - ARM Mali 450 GPU
 - 2GB DDR3 SDRAM
 - Gigabit Ethernet
 - HDMI 2.0 4K/60Hz display
 - 40-pin GPIO header
 - 4 x USB 2.0 Host, 1 x USB OTG
 - eMMC, microSD
 - Infrared receiver

Schematics are available on the manufacturer website.

U-Boot Compilation
------------------

.. code-block:: bash

    $ export CROSS_COMPILE=aarch64-none-elf-
    $ make nanopi-k2_defconfig
    $ make

U-Boot Signing with Pre-Built FIP repo
--------------------------------------

.. code-block:: bash

    $ git clone https://github.com/LibreELEC/amlogic-boot-fip --depth=1
    $ cd amlogic-boot-fip
    $ 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

    $ wget https://releases.linaro.org/archive/13.11/components/toolchain/binaries/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz
    $ wget https://releases.linaro.org/archive/13.11/components/toolchain/binaries/gcc-linaro-arm-none-eabi-4.8-2013.11_linux.tar.xz
    $ 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/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
    $ sed -i 's/arm-linux-/arm-none-eabi-/' arch/arm/cpu/armv8/gxb/firmware/scp_task/Makefile
    $ make nanopi-k2_defconfig
    $ make
    $ export FIPDIR=$PWD/fip

Go back to the mainline U-Boot source tree then:

.. code-block:: bash

    $ mkdir fip

    $ cp $FIPDIR/gxb/bl2.bin fip/
    $ cp $FIPDIR/gxb/acs.bin fip/
    $ cp $FIPDIR/gxb/bl21.bin fip/
    $ cp $FIPDIR/gxb/bl30.bin fip/
    $ 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 \
              fip/zero_tmp \
              fip/bl30_zero.bin \
              fip/bl301.bin \
              fip/bl301_zero.bin \
              fip/bl30_new.bin \
              bl30

    $ $FIPDIR/fip_create --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 \
              fip/bl2_acs.bin \
              fip/zero_tmp \
              fip/bl2_zero.bin \
              fip/bl21.bin \
              fip/bl21_zero.bin \
              fip/bl2_new.bin \
              bl2

    $ cat fip/bl2_new.bin fip/fip.bin > fip/boot_new.bin

    $ $FIPDIR/gxb/aml_encrypt_gxb --bootsig \
                                  --input fip/boot_new.bin
                                  --output fip/u-boot.bin

Then write U-Boot to SD or eMMC with:

.. code-block:: bash

    $ DEV=/dev/boot_device
    $ 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