| # 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 |