--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0+
+
+U-Boot for BananaPi M2S (A311D & S922X)
+=======================================
+
+BananaPi BPI-M2S ships is a Single Board Computer manufactured by Sinovoip that ships in
+two variants with Amlogic S922X or A311D SoC and the following common specification:
+
+- 16GB eMMC
+- HDMI 2.1a video
+- 2x 10/100/1000 Base-T Ethernet (1x RTL8211F, 1x RTL811H)
+- 2x USB 2.0 ports
+- 2x Status LED's (green/blue)
+- 1x Power/Reset button
+- 1x micro SD card slot
+- 40-pin GPIO header
+- PWM fan header
+- UART header
+
+The S992X variant has:
+- 2GB LPDDR4 RAM
+
+The A311D variant has:
+
+- 4GB LPDDR4 RAM
+- NPU (5.0 TOPS)
+- MIPI DSI header
+- MIPI CSI header
+
+An optional RTL8822CS SDIO WiFi/BT mezzanine is available for both board variants.
+
+Schematics are available from the manufacturer: https://wiki.banana-pi.org/Banana_Pi_BPI-M2S
+
+U-Boot Compilation
+------------------
+
+.. code-block:: bash
+
+ $ export CROSS_COMPILE=aarch64-none-elf-
+ $ make bananapi-m2s_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 bananapi-m2s /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
+
+ $ DIR=bananapi-m2s
+ $ git clone --depth 1 https://github.com/Dangku/amlogic-u-boot.git -b khadas-g12b-v2015.01-m2s $DIR
+
+ $ cd $DIR
+ $ make bananapi_m2s_defconfig
+ $ make
+ $ export UBDIR=$PWD
+
+Go back to the mainline U-Boot source tree then:
+
+.. code-block:: bash
+
+ $ mkdir fip
+
+ $ wget https://github.com/BayLibre/u-boot/releases/download/v2017.11-libretech-cc/blx_fix_g12a.sh -O fip/blx_fix.sh
+ $ cp $UBDIR/build/scp_task/bl301.bin fip/
+ $ cp $UBDIR/build/board/bananapi/bananpi_m2s/firmware/acs.bin fip/
+ $ cp $UBDIR/fip/g12a/bl2.bin fip/
+ $ cp $UBDIR/fip/g12a/bl30.bin fip/
+ $ cp $UBDIR/fip/g12a/bl31.img fip/
+ $ cp $UBDIR/fip/g12a/ddr3_1d.fw fip/
+ $ cp $UBDIR/fip/g12a/ddr4_1d.fw fip/
+ $ cp $UBDIR/fip/g12a/ddr4_2d.fw fip/
+ $ cp $UBDIR/fip/g12a/diag_lpddr4.fw fip/
+ $ cp $UBDIR/fip/g12a/lpddr3_1d.fw fip/
+ $ cp $UBDIR/fip/g12a/lpddr4_1d.fw fip/
+ $ cp $UBDIR/fip/g12a/lpddr4_2d.fw fip/
+ $ cp $UBDIR/fip/g12a/piei.fw fip/
+ $ cp $UBDIR/fip/g12a/aml_ddr.fw fip/
+ $ cp u-boot.bin fip/bl33.bin
+
+ $ sh fip/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
+
+ $ sh fip/blx_fix.sh \
+ fip/bl2.bin \
+ fip/zero_tmp \
+ fip/bl2_zero.bin \
+ fip/acs.bin \
+ fip/bl21_zero.bin \
+ fip/bl2_new.bin \
+ bl2
+
+ $ $UBDIR/fip/g12b/aml_encrypt_g12b --bl30sig --input fip/bl30_new.bin \
+ --output fip/bl30_new.bin.g12a.enc \
+ --level v3
+ $ $UBDIR/fip/g12b/aml_encrypt_g12b --bl3sig --input fip/bl30_new.bin.g12a.enc \
+ --output fip/bl30_new.bin.enc \
+ --level v3 --type bl30
+ $ $UBDIR/fip/g12b/aml_encrypt_g12b --bl3sig --input fip/bl31.img \
+ --output fip/bl31.img.enc \
+ --level v3 --type bl31
+ $ $UBDIR/fip/g12b/aml_encrypt_g12b --bl3sig --input fip/bl33.bin --compress lz4 \
+ --output fip/bl33.bin.enc \
+ --level v3 --type bl33 --compress lz4
+ $ $UBDIR/fip/g12b/aml_encrypt_g12b --bl2sig --input fip/bl2_new.bin \
+ --output fip/bl2.n.bin.sig
+ $ $UBDIR/fip/g12b/aml_encrypt_g12b --bootmk \
+ --output fip/u-boot.bin \
+ --bl2 fip/bl2.n.bin.sig \
+ --bl30 fip/bl30_new.bin.enc \
+ --bl31 fip/bl31.img.enc \
+ --bl33 fip/bl33.bin.enc \
+ --ddrfw1 fip/ddr4_1d.fw \
+ --ddrfw2 fip/ddr4_2d.fw \
+ --ddrfw3 fip/ddr3_1d.fw \
+ --ddrfw4 fip/piei.fw \
+ --ddrfw5 fip/lpddr4_1d.fw \
+ --ddrfw6 fip/lpddr4_2d.fw \
+ --ddrfw7 fip/diag_lpddr4.fw \
+ --ddrfw8 fip/aml_ddr.fw \
+ --ddrfw9 fip/lpddr3_1d.fw \
+ --level v3
+
+Then write the image to SD or eMMC with:
+
+.. code-block:: bash
+
+ $ DEV=/dev/boot_device
+ $ dd if=fip/u-boot.bin.sd.bin of=$DEV conv=fsync,notrunc bs=512 skip=1 seek=1
+ $ dd if=fip/u-boot.bin.sd.bin of=$DEV conv=fsync,notrunc bs=1 count=440