board: synquacer: Add DeveloperBox 96boards EE support

Add the DeveloperBox 96boards EE support. This board is also
known as Socionext SynQuacer E-Series. It contians one "SC2A11"
SoC, which has 24-cores of arm Cortex-A53, and 4 DDR3 slots,
3 PCIe slots (1 4x port and 2 1x ports which are expanded via
PCIe bridge chip), 2 USB 3.0 ports and 2 USB 2.0 ports, 2 SATA
ports and 1 GbE, 64MB NOR flash and 8GB eMMC on standard
MicroATX Form Factor.

For more information, see this page;
  https://www.96boards.org/product/developerbox/

Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>

doc/board/index.rst

@@ -22,6 +22,7 @@ Board-specific doc
    rockchip/index
    sifive/index
    sipeed/index
+   socionext/index
    st/index
    tbs/index
    toradex/index

doc/board/socionext/developerbox.rst

@@ -0,0 +1,87 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Introduction
+============
+
+DeveloperBox is a certified 96boards Enterprise Edition board. The board/SoC has: -
+
+* Socionext SC2A11 24-cores ARM Cortex-A53 on tbe Mini-ATX form factor motherboard
+* 4 DIMM slots (4GB DDR4-2400 UDIMM shipped by default)
+* 1 4xPCIe Gen2 slot and 2 1xPCIe Gen2 slots
+  (1x slots are connected via PCIe bridge chip)
+* 4 USB-3.0 ports
+* 2 SATA ports
+* 1 GbE network port
+* 1 USB-UART serial port (micro USB)
+* 64MB SPI NOR Flash
+* 8GB eMMC Flash Storage
+* 96boards LS connector
+
+The DeveloperBox schematic can be found here: -
+https://www.96boards.org/documentation/enterprise/developerbox/hardware-docs/mzsc2am_v03_20180115_a.pdf
+
+And the other documents can be found here: -
+https://www.96boards.org/documentation/enterprise/developerbox/
+
+
+Currently, the U-Boot port supports: -
+
+* USB
+* eMMC
+* SPI-NOR
+* SATA
+* GbE
+
+The DeveloperBox boots the TF-A and EDK2 as a main bootloader by default.
+The DeveloperBox U-Boot port will replace the EDK2 and boot from TF-A as
+BL33, but no need to combine with it.
+
+Compile from source
+===================
+
+You can build U-Boot without any additinal source code.::
+
+  cd u-boot
+  export ARCH=arm64
+  export CROSS_COMPILE=aarch64-linux-gnu-
+  make SynQuacer_defconfig
+  make -j `noproc`
+
+Then, expand the binary to 1MB for preparing flash.::
+
+  cp u-boot.bin SPI_NOR_UBOOT.fd
+  truncate -s 1M SPI_NOR_UBOOT.fd
+
+Installation
+============
+
+You can install the SNI_NOR_UBOOT.fd via NOR flash writer.
+
+Flashing the U-Boot image on DeveloperBox requires a 96boards UART mezzanine or other mezzanine which can connect to LS-UART0 port.
+Connect USB cable from host to the LS-UART0 and set DSW2-7 to ON, and turn the board on again. The flash writer program will be started automatically; don’t forget to turn the DSW2-7 off again after flashing.
+
+*!!CAUTION!! If you failed to write the U-Boot image on wrong address, the board can be bricked. See below page if you need to recover the bricked board. See the following page for more detail*
+
+https://www.96boards.org/documentation/enterprise/developerbox/installation/board-recovery.md.html
+
+When the serial flasher is running correctly is will show the following boot messages shown via LS-UART0::
+
+
+  /*------------------------------------------*/
+  /*  SC2A11 "SynQuacer" series Flash writer  */
+  /*                                          */
+  /*  Version: cd254ac                        */
+  /*  Build: 12/15/17 11:25:45                */
+  /*------------------------------------------*/
+
+  Command Input >
+
+Once the flasher tool is running we are ready flash the UEFI image::
+
+  flash rawwrite 200000 100000
+  >> Send SPI_NOR_UBOOT.fd via XMODEM (Control-A S in minicom) <<
+
+*!!NOTE!! The flasher command parameter is different from the command for board recovery. U-Boot uses the offset 200000 (2-five-0, 2M in hex) and the size 100000 (1-five-0, 1M in hex).*
+
+After transferring the SPI_NOR_UBOOT.fd, turn off the DSW2-7 and reset the board.
+

doc/board/socionext/index.rst

@@ -0,0 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Socionext
+=========
+
+.. toctree::
+   :maxdepth: 2
+
+   developerbox