--- /dev/null
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2018 MediaTek Inc.
+# Ryder Lee <ryder.lee@kernel.org>
+
+
+This document describes how to compile the U-Boot and how to change U-Boot
+configuration about the MediaTek SoCs.
+
+
+Build Procedure
+===============
+ -Set the cross compiler:
+
+ # export CROSS_COMPILE=/path/to/toolchain/arm-linux-gnueabi-
+
+ -Clean-up old residuals:
+
+ # make mrproper
+
+ -Configure the U-Boot:
+
+ # make <defconfig_file>
+ # make
+
+ - For the MT7623n bananapi R2 board use "mt7623n_bpir2_defconfig"
+ - For the MT7629 reference board use "mt7629_rfb_defconfig"
+
+
+Boot sequence
+=============
+ -Bootrom -> MTK preloader -> U-Boot
+
+ - MT7623n
+
+ This version of U-Boot doesn't implement SPL. So, MTK preloader binary
+ is needed to boot up:
+
+ https://github.com/BPI-SINOVOIP/BPI-R2-bsp/tree/master/mt-pack/mtk/bpi-r2/bin
+
+
+ -Bootrom -> SPL -> U-Boot
+
+ - MT7629
+
+
+Configuration update
+====================
+ To update the U-Boot configuration, please refer to doc/README.kconfig
+
+
+MediaTek image header
+=====================
+Currently there are two image headers used for MediaTek chips:
+
+ - BootROM image header. This header is used by the first stage bootloader. It records
+ the desired compatible boot device, integrity information and its load address.
+
+ The on-chip BootROM will firstly verify integrity and compatibility of the bootloader.
+
+ If verification passed, the BootROM will then load the bootloader into on-chip SRAM,
+ and pass control to it.
+
+ Note that this header is actually a combination of three independent headers:
+ Device header, BRLYT header and GFH header.
+
+ Used by U-Boot SPL of MT7629 and preloader of MT7623.
+
+
+ - MediaTek legacy image header. This header was originally used by the legacy image. It
+ basically records the load address, image size and image name.
+
+ After all low level initializations passed, the preloader will locate the LK image and
+ load it into DRAM, and pass control to it.
+
+ Now this header is used by U-Boot of MT7623.
+
+
+To generate these two headers with mkimage:
+
+ # mkimage -T mtk_image -a <load_addr> -n <option_string> -d <input_file> <image_file>
+
+ - mtk_image means using MediaTek's header generation method.
+
+
+ - load_addr is the load address of this image.
+ For first stage bootloader like U-Boot SPL or preloader, it usually points to the
+ on-chip SRAM.
+
+ For second stage bootloader like U-Boot, it usually points to the DRAM.
+
+
+ - option_string contains options to generate the header.
+
+ The option string is using the follow format:
+ key1=value1;key2=value2;...
+
+ The following key names are valid:
+ lk: If lk=1, LK image header is used. Otherwise BootROM image header is used.
+
+ lkname: The name of the LK image header. The maximum length is 32.
+ The default value is "U-Boot".
+
+ media: Desired boot device. The valid values are:
+ nand : Parallel NAND
+ snand: Serial NAND
+ nor : Serial NOR
+ emmc : eMMC
+ sdmmc: SD
+
+ nandinfo: Desired NAND device type, a combination of page size, oob size and
+ optional device capacity. Valid types are:
+ 2k+64 : for Serial NAND, 2KiB page size + 64B oob size
+ 2k+120 : for Serial NAND, 2KiB page size + 120B oob size
+ 2k+128 : for Serial NAND, 2KiB page size + 128B oob size
+ 4k+256 : for Serial NAND, 4KiB page size + 256B oob size
+ 1g:2k+64 : for Parallel NAND, 2KiB page size + 64B oob size, total 1Gbit size
+ 2g:2k+64 : for Parallel NAND, 2KiB page size + 64B oob size, total 2Gbit size
+ 4g:2k+64 : for Parallel NAND, 2KiB page size + 64B oob size, total 4Gbit size
+ 2g:2k+128: for Parallel NAND, 2KiB page size + 128B oob size, total 2Gbit size
+ 4g:2k+128: for Parallel NAND, 2KiB page size + 128B oob size, total 4Gbit size
+
+
+MT7629 partitions on Serial NOR
+===============================
+
+ Start End Size Description
+ 00000000 - 0000ffff: 64KiB U-Boot SPL
+ 00010000 - 0005ffff: 320KiB U-Boot
+ 00060000 - 0006ffff: 64KiB U-Boot env / MediaTek NVRAM
+ 00070000 - 000affff: 256KiB RF calibration data
+ 000b0000 - xxxxxxxx: all left Firmware image
+
+
+BPi-R2 (MT7623N) partitions on SD
+=================================
+ Please note that the last two partitions can vary from different Linux distributions
+ depending on the MBR partition table.
+
+ Start End Size Description
+ 00000000 - 000001ff: 512B Device header (with MBR partition table)
+ 00000200 - 000007ff: 1536B BRLYT header
+ 00000800 - 0004ffff: 318KiB Preloader (with GFH header)
+ 00050000 - 000fffff: 704KiB U-Boot
+ 00100000 - 063fffff: 99MiB Reserved
+ 06400000 - 163fffff: 256MiB Partition 1 (FAT32)
+ 16400000 - xxxxxxxx: all left Partition 2 (ext4)
+
+
+Upgrading notice on Serial NOR
+==============================
+Example: MT7629
+
+ The command sf is used to operate the Serial NOR device:
+
+ - To probe current NOR flash:
+
+ # sf probe
+
+ - To erase a region:
+
+ # sf erase <offset> <len>
+
+ - To write data to an offset:
+
+ # sf write <data_addr> <offset> <len>
+
+ - To boot kernel:
+
+ # bootm 0x300b0000
+
+ The memory address range 0x30000000 - 0x3fffffff is mapped to the NOR flash.
+ The DRAM starts at 0x40000000.
+
+ Please note that the output binary u-boot-mtk.bin is a combination of SPL and U-Boot,
+ and it should be write to beginning of the flash.
+
+ Otherwise you should use standalone files:
+
+ spl/u-boot-spl-mtk.bin for SPL,
+ u-boot.img for U-Boot.
+
+
+Upgrading notice on SD / eMMC
+=============================
+Example: MT7623
+
+ Normally only Preloader and U-Boot can be upgraded within U-Boot, and other partitions
+ should be written in PC.
+
+ - To probe current SD card / eMMC:
+
+ # mmc dev 0 for eMMC
+ # mmc dev 1 for SD
+
+ - To erase a region:
+
+ # mmc erase <blk_offset> <blk_num>
+
+ - To write data to a block offset:
+
+ # mmc write <data_addr> <blk_offset> <blk_num>
+
+ - To load kernel image from partition 1:
+
+ # fatload mmc 0:1 <load_address> <path_to_kernel_uImage> for eMMC
+ # fatload mmc 1:1 <load_address> <path_to_kernel_uImage> for SD
+
+ - To boot kernel:
+
+ # bootm <load_address>
+
+ The DRAM starts at 0x80000000.
+
+ Please note that we use block offset and block count for SD card, not the byte offset.
+ The block size is always 512 bytes for SD card.
+
+
+Documentation
+=============
+ http://wiki.banana-pi.org/Banana_Pi_BPI-R2
projects / u-boot.git / commitdiff