Add a few notes on how to try out the MediaTek support so far.
Signed-off-by: Ryder Lee ryder.lee@mediatek.com --- Changes since v4: -Add instructions on how to prepare SD card and write to SNOR flash. -Fix typo. --- doc/README.mediatek | 221 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 221 insertions(+) create mode 100644 doc/README.mediatek
diff --git a/doc/README.mediatek b/doc/README.mediatek new file mode 100644 index 0000000..5b8e3e9 --- /dev/null +++ b/doc/README.mediatek @@ -0,0 +1,221 @@ +# 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/bi... + + + -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