1 SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause 2 # 3 # Copyright (C) 2018 STMicroelectronics - All Rights Reserved 4 # 5 6 U-Boot on STMicroelectronics STM32MP1 7 ====================================== 8 9 1. Summary 10 ========== 11 This is a quick instruction for setup stm32mp1 boards. 12 13 2. Supported devices 14 ==================== 15 U-Boot supports one STMP32MP1 SoCs: STM32MP157 16 17 The STM32MP157 is a Cortex-A MPU aimed at various applications. 18 It features: 19 - Dual core Cortex-A7 application core 20 - 2D/3D image composition with GPU 21 - Standard memories interface support 22 - Standard connectivity, widely inherited from the STM32 MCU family 23 - Comprehensive security support 24 25 Everything is supported in Linux but U-Boot is limited to: 26 1. UART 27 2. SDCard/MMC controller (SDMMC) 28 29 And the necessary drivers 30 1. I2C 31 2. STPMU1 32 3. Clock, Reset 33 34 Currently the following boards are supported: 35 + stm32mp157c-ed1 36 37 3. Boot Sequences 38 ================= 39 40 BootRom => FSBL in SYSRAM => SSBL in DDR => OS (Linux Kernel) 41 42 with FSBL = First Stage Bootloader 43 SSBL = Second Stage Bootloader 44 45 One boot configuration is supported: 46 47 The "Basic" boot chain (defconfig_file : stm32mp15_basic_defconfig) 48 BootRom => FSBL = U-Boot SPL => SSBL = U-Boot 49 SPL has limited security initialisation 50 U-Boot is running in secure mode and provide a secure monitor to the kernel 51 with only PSCI support (Power State Coordination Interface defined by ARM) 52 53 All the STM32MP1 board supported by U-Boot use the same generic board 54 stm32mp1 which support all the bootable devices. 55 56 Each board is configurated only with the associated device tree. 57 58 4. Device Tree Selection 59 ======================== 60 61 You need to select the appropriate device tree for your board, 62 the supported device trees for stm32mp157 are: 63 64 + ed1: daughter board with pmic stpmu1 65 dts: stm32mp157c-ed1 66 67 5. Build Procedure 68 ================== 69 70 1. Install required tools for U-Boot 71 72 + install package needed in U-Boot makefile 73 (libssl-dev, swig, libpython-dev...) 74 + install ARMv7 toolchain for 32bit Cortex-A (from Linaro, 75 from SDK for STM32MP1, or any crosstoolchains from your distribution) 76 77 2. Set the cross compiler: 78 79 # export CROSS_COMPILE=/path/to/toolchain/arm-linux-gnueabi- 80 (you can use any gcc cross compiler compatible with U-Boot) 81 82 3. Select the output directory (optional) 83 84 # export KBUILD_OUTPUT=/path/to/output 85 86 for example: use one output directory for each configuration 87 # export KBUILD_OUTPUT=stm32mp15_basic 88 89 4. Configure the U-Boot: 90 91 # make <defconfig_file> 92 93 - For basic boot mode: "stm32mp15_basic_defconfig" 94 95 5. Configure the device-tree and build the U-Boot image: 96 97 # make DEVICE_TREE=<name> all 98 99 100 example: 101 basic boot on ed1 102 # export KBUILD_OUTPUT=stm32mp15_basic 103 # make stm32mp15_basic_defconfig 104 # make DEVICE_TREE=stm32mp157c-ed1 all 105 106 6. Output files 107 108 BootRom and ATF expect binaries with STM32 image header 109 SPL expects file with U-Boot uImage header 110 111 So in the output directory (selected by KBUILD_OUTPUT), 112 you can found the needed files: 113 114 + FSBL = spl/u-boot-spl.stm32 115 + SSBL = u-boot.img 116 117 6. Switch Setting for Boot Mode 118 =============================== 119 120 You can select the boot mode, on the board ed1 with the switch SW1 121 122 ----------------------------------- 123 Boot Mode BOOT2 BOOT1 BOOT0 124 ----------------------------------- 125 Reserved 0 0 0 126 NOR 0 0 1 127 SD-Card 1 1 1 128 SD-Card 1 0 1 129 eMMC 0 1 0 130 NAND 0 1 1 131 Recovery 1 1 0 132 Recovery 0 0 0 133 134 Recovery is a boot from serial link (UART/USB) and it is used with 135 STM32CubeProgrammer tool to load executable in RAM and to update the flash 136 devices available on the board (NOR/NAND/eMMC/SDCARD). 137 The communication between HOST and board is based on 138 - for UARTs : the uart protocol used with all MCU STM32 139 - for USB : based on USB DFU 1.1 (without the ST extensions used on MCU STM32) 140 141 7. Prepare an SDCard 142 =================== 143 144 The minimal requirements for STMP32MP1 boot up to U-Boot are: 145 - GPT partitioning (with gdisk or with sgdisk) 146 - 2 fsbl partitions, named fsbl1 and fsbl2, size at least 256KiB 147 - one ssbl partition for U-Boot 148 149 Then the minimal GPT partition is: 150 ----- ------- --------- ------------- 151 | Num | Name | Size | Content | 152 ----- ------- -------- -------------- 153 | 1 | fsbl1 | 256 KiB | ATF or SPL | 154 | 2 | fsbl2 | 256 KiB | ATF or SPL | 155 | 3 | ssbl | enought | U-Boot | 156 | * | - | - | Boot/Rootfs| 157 ----- ------- --------- ------------- 158 159 (*) add bootable partition for extlinux.conf 160 following Generic Distribution 161 (doc/README.distro for use) 162 163 according the used card reader select the block device 164 (/dev/sdx or /dev/mmcblk0) 165 in the next example I use /dev/mmcblk0 166 167 for example: with gpt table with 128 entries 168 169 a) remove previous formatting 170 # sgdisk -o /dev/<SDCard dev> 171 172 b) create minimal image 173 # sgdisk --resize-table=128 -a 1 \ 174 -n 1:34:545 -c 1:fsbl1 \ 175 -n 2:546:1057 -c 2:fsbl2 \ 176 -n 3:1058:5153 -c 3:ssbl \ 177 -p /dev/<SDCard dev> 178 179 you can add other partition for kernel (rootfs for example) 180 181 c) copy the FSBL (2 times) and SSBL file on the correct partition. 182 in this example in partition 1 to 3 183 184 for basic boot mode : <SDCard dev> = /dev/mmcblk0 185 # dd if=u-boot-spl.stm32 of=/dev/mmcblk0p1 186 # dd if=u-boot-spl.stm32 of=/dev/mmcblk0p2 187 # dd if=u-boot.img of=/dev/mmcblk0p3 188 189 To boot from SDCard, select BootPinMode = 1 1 1 and reset. 190 191 8. Prepare eMMC 192 =============== 193 You can use U-Boot to copy binary in eMMC. 194 195 In the next example, you need to boot from SDCARD and the images (u-boot-spl.stm32, u-boot.img) 196 are presents on SDCARD (mmc 0) in ext4 partition 4 (bootfs). 197 198 To boot from SDCard, select BootPinMode = 1 1 1 and reset. 199 200 Then you update the eMMC with the next U-Boot command : 201 202 a) prepare GPT on eMMC, 203 example with 2 partitions, bootfs and roots: 204 205 # setenv emmc_part "name=ssbl,size=2MiB;name=bootfs,type=linux,bootable,size=64MiB;name=rootfs,type=linux,size=512" 206 # gpt write mmc 1 ${emmc_part} 207 208 b) copy SPL on eMMC on firts boot partition 209 (SPL max size is 256kB, with LBA 512, 0x200) 210 211 # ext4load mmc 0:4 0xC0000000 u-boot-spl.stm32 212 # mmc dev 1 213 # mmc partconf 1 1 1 1 214 # mmc write ${fileaddr} 0 200 215 # mmc partconf 1 1 1 0 216 217 b) copy U-Boot in first GPT partition of eMMC 218 219 # ext4load mmc 0:4 0xC0000000 u-boot.img 220 # mmc dev 1 221 # part start mmc 1 1 partstart 222 # part size mmc 1 1 partsize 223 # mmc write ${fileaddr} ${partstart} ${partsize} 224 225 To boot from eMMC, select BootPinMode = 0 1 0 and reset. 226
