new file mode 100644
@@ -0,0 +1,48 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+mt7621_rfb/mt7621_nand_rfb
+==========================
+
+U-Boot for the MediaTek MT7621 boards
+
+Quick Start
+-----------
+
+- Get the DDR initialization binary blob
+- Configure CPU and DDR parameters
+- Build U-Boot
+
+Get the DDR initialization binary blob
+--------------------
+
+Download one from:
+ - https://raw.githubusercontent.com/mtk-openwrt/mt7621-lowlevel-preloader/master/mt7621_stage_sram.bin
+ - https://raw.githubusercontent.com/mtk-openwrt/mt7621-lowlevel-preloader/master/mt7621_stage_sram_noprint.bin
+
+mt7621_stage_sram_noprint.bin has removed all output logs. To use this one,
+download and rename it to mt7621_stage_sram.bin
+
+Put the binary blob to the u-boot build directory.
+
+Configure CPU and DDR parameters
+--------------------------------
+
+menuconfig > MIPS architecture > MediaTek MIPS platforms > CPU & DDR configuration
+
+Select the correct DDR timing parameters for your board. The size shown here
+must match the DDR size of you board.
+
+The frequency of CPU and DDR can also be adjusted.
+
+Build U-Boot
+------------
+
+.. code-block:: bash
+
+ $ export CROSS_COMPILE=mipsel-linux-
+ $ make O=build mt7621_rfb_defconfig # or mt7621_nand_rfb_defconfig
+ $ cp mt7621_stage_sram.bin ./build/mt7621_stage_sram.bin
+ $ # or cp mt7621_stage_sram_noprint.bin ./build/mt7621_stage_sram.bin
+ $ make O=build
+
+Burn the u-boot-mt7621.bin to the SPI-NOR or NAND flash.
The MT7621 requires external binary blob being executed during u-boot's boot-up flow. It's necessary to provide a guide here for users to correctly build the u-boot. Signed-off-by: Weijie Gao <weijie.gao@mediatek.com> --- v5 changes: none v4 changes: new --- doc/board/mediatek/mt7621.rst | 48 +++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 doc/board/mediatek/mt7621.rst