1Introduction: 2------------- 3The AM65x family of SoCs is the first device family from K3 Multicore 4SoC architecture, targeted for broad market and industrial control with 5aim to meet the complex processing needs of modern embedded products. 6 7The device is built over three domains, each containing specific processing 8cores, voltage domains and peripherals: 91. Wake-up (WKUP) domain: 10 - Device Management and Security Controller (DMSC) 112. Microcontroller (MCU) domain: 12 - Dual Core ARM Cortex-R5F processor 133. MAIN domain: 14 - Quad core 64-bit ARM Cortex-A53 15 16More info can be found in TRM: http://www.ti.com/lit/pdf/spruid7 17 18Boot Flow: 19---------- 20On AM65x family devices, ROM supports boot only via MCU(R5). This means that 21bootloader has to run on R5 core. In order to meet this constraint, and for 22the following reasons the boot flow is designed as mentioned: 231. Need to move away from R5 asap, so that we want to start *any* 24firmware on the r5 cores like.... autosar can be loaded to receive CAN 25response and other safety operations to be started. This operation is 26very time critical and is applicable for all automotive use cases. 272. U-Boot on A53 should start other remotecores for various 28applications. This should happen before running Linux. 293. In production boot flow, we might not like to use full u-boot, 30instead use Flacon boot flow to reduce boot time. 31 32+------------------------------------------------------------------------+ 33| DMSC | R5 | A53 | 34+------------------------------------------------------------------------+ 35| +--------+ | | | 36| | Reset | | | | 37| +--------+ | | | 38| : | | | 39| +--------+ | +-----------+ | | 40| | *ROM* |----------|-->| Reset rls | | | 41| +--------+ | +-----------+ | | 42| | | | : | | 43| | ROM | | : | | 44| |services| | : | | 45| | | | +-------------+ | | 46| | | | | *R5 ROM* | | | 47| | | | +-------------+ | | 48| | |<---------|---|Load and auth| | | 49| | | | | tiboot3.bin | | | 50| | | | +-------------+ | | 51| | | | : | | 52| | | | : | | 53| | | | : | | 54| | | | +-------------+ | | 55| | | | | *R5 SPL* | | | 56| | | | +-------------+ | | 57| | | | | Load | | | 58| | | | | sysfw.itb | | | 59| | Start | | +-------------+ | | 60| | System |<---------|---| Start | | | 61| |Firmware| | | SYSFW | | | 62| +--------+ | +-------------+ | | 63| : | | | | | 64| +---------+ | | Load | | | 65| | *SYSFW* | | | system | | | 66| +---------+ | | Config data | | | 67| | |<--------|---| | | | 68| | | | +-------------+ | | 69| | | | | | | | 70| | | | | DDR | | | 71| | | | | config | | | 72| | | | +-------------+ | | 73| | | | | | | | 74| | |<--------|---| Start A53 | | | 75| | | | | and Reset | | | 76| | | | +-------------+ | | 77| | | | | +-----------+ | 78| | |---------|-----------------------|---->| Reset rls | | 79| | | | | +-----------+ | 80| | DMSC | | | : | 81| |Services | | | +-----------+ | 82| | |<--------|-----------------------|---->|*ATF/OPTEE*| | 83| | | | | +-----------+ | 84| | | | | : | 85| | | | | +-----------+ | 86| | |<--------|-----------------------|---->| *A53 SPL* | | 87| | | | | +-----------+ | 88| | | | | | Load | | 89| | | | | | u-boot.img| | 90| | | | | +-----------+ | 91| | | | | : | 92| | | | | +-----------+ | 93| | |<--------|-----------------------|---->| *U-Boot* | | 94| | | | | +-----------+ | 95| | | | | | prompt | | 96| | | | | +-----------+ | 97| +---------+ | | | 98| | | | 99+------------------------------------------------------------------------+ 100 101- Here DMSC acts as master and provides all the critical services. R5/A53 102requests DMSC to get these services done as shown in the above diagram. 103 104Sources: 105-------- 1061. SYSFW: 107 Tree: git://git.ti.com/k3-image-gen/k3-image-gen.git 108 Branch: master 109 1102. ATF: 111 Tree: https://github.com/ARM-software/arm-trusted-firmware.git 112 Branch: master 113 1143. OPTEE: 115 Tree: https://github.com/OP-TEE/optee_os.git 116 Branch: master 117 1184. U-Boot: 119 Tree: http://git.denx.de/u-boot.git 120 Branch: master 121 122Build procedure: 123---------------- 1241. SYSFW: 125$ make CROSS_COMPILE=arm-linux-gnueabihf- 126 1272. ATF: 128$ make CROSS_COMPILE=aarch64-linux-gnu- ARCH=aarch64 PLAT=k3 TARGET_BOARD=generic SPD=opteed 129 1303. OPTEE: 131$ make PLATFORM=k3-am65x CFG_ARM64_core=y 132 1334. U-Boot: 134 1354.1. R5: 136$ make CROSS_COMPILE=arm-linux-gnueabihf- am65x_evm_r5_defconfig O=/tmp/r5 137$ make CROSS_COMPILE=arm-linux-gnueabihf- O=/tmp/r5 138 1394.2. A53: 140$ make CROSS_COMPILE=aarch64-linux-gnu- am65x_evm_a53_defconfig O=/tmp/a53 141$ make CROSS_COMPILE=aarch64-linux-gnu- ATF=<path to ATF dir>/build/k3/generic/release/bl31.bin TEE=<path to OPTEE OS dir>/out/arm-plat-k3/core/tee-pager_v2.bin O=/tmp/a53 142 143Target Images 144-------------- 145Copy the below images to an SD card and boot: 146- sysfw.itb from step 1 147- tiboot3.bin from step 4.1 148- tispl.bin, u-boot.img from 4.2 149 150Image formats: 151-------------- 152 153- tiboot3.bin: 154 +-----------------------+ 155 | X.509 | 156 | Certificate | 157 | +-------------------+ | 158 | | | | 159 | | R5 | | 160 | | u-boot-spl.bin | | 161 | | | | 162 | +-------------------+ | 163 | | | | 164 | | FIT header | | 165 | | +---------------+ | | 166 | | | | | | 167 | | | DTB 1...N | | | 168 | | +---------------+ | | 169 | +-------------------+ | 170 +-----------------------+ 171 172- tispl.bin 173 +-----------------------+ 174 | | 175 | FIT HEADER | 176 | +-------------------+ | 177 | | | | 178 | | A53 ATF | | 179 | +-------------------+ | 180 | | | | 181 | | A53 OPTEE | | 182 | +-------------------+ | 183 | | | | 184 | | A53 SPL | | 185 | +-------------------+ | 186 | | | | 187 | | SPL DTB 1...N | | 188 | +-------------------+ | 189 +-----------------------+ 190 191- sysfw.itb 192 +-----------------------+ 193 | | 194 | FIT HEADER | 195 | +-------------------+ | 196 | | | | 197 | | sysfw.bin | | 198 | +-------------------+ | 199 | | | | 200 | | board config | | 201 | +-------------------+ | 202 | | | | 203 | | PM config | | 204 | +-------------------+ | 205 | | | | 206 | | RM config | | 207 | +-------------------+ | 208 | | | | 209 | | Secure config | | 210 | +-------------------+ | 211 +-----------------------+ 212 213eMMC: 214----- 215ROM supports booting from eMMC from boot0 partition offset 0x0 216 217Flashing images to eMMC: 218 219The following commands can be used to download tiboot3.bin, tispl.bin, 220u-boot.img, and sysfw.itb from an SD card and write them to the eMMC boot0 221partition at respective addresses. 222 223=> mmc dev 0 1 224=> fatload mmc 1 ${loadaddr} tiboot3.bin 225=> mmc write ${loadaddr} 0x0 0x400 226=> fatload mmc 1 ${loadaddr} tispl.bin 227=> mmc write ${loadaddr} 0x400 0x1000 228=> fatload mmc 1 ${loadaddr} u-boot.img 229=> mmc write ${loadaddr} 0x1400 0x2000 230=> fatload mmc 1 ${loadaddr} sysfw.itb 231=> mmc write ${loadaddr} 0x3600 0x800 232 233To give the ROM access to the boot partition, the following commands must be 234used for the first time: 235=> mmc partconf 0 1 1 1 236=> mmc bootbus 0 1 0 0 237 238To create a software partition for the rootfs, the following command can be 239used: 240=> gpt write mmc 0 ${partitions} 241 242eMMC layout: 243 244 boot0 partition (8 MB) user partition 245 0x0+----------------------------------+ 0x0+-------------------------+ 246 | tiboot3.bin (512 KB) | | | 247 0x400+----------------------------------+ | | 248 | tispl.bin (2 MB) | | | 2490x1400+----------------------------------+ | rootfs | 250 | u-boot.img (4 MB) | | | 2510x3400+----------------------------------+ | | 252 | environment (128 KB) | | | 2530x3500+----------------------------------+ | | 254 | backup environment (128 KB) | | | 2550x3600+----------------------------------+ | | 256 | sysfw (1 MB) | | | 2570x3E00+----------------------------------+ +-------------------------+ 258 259Kernel image and DT are expected to be present in the /boot folder of rootfs. 260To boot kernel from eMMC, use the following commands: 261=> setenv mmcdev 0 262=> setenv bootpart 0 263=> boot 264 265OSPI: 266----- 267ROM supports booting from OSPI from offset 0x0. 268 269Flashing images to OSPI: 270 271Below commands can be used to download tiboot3.bin, tispl.bin, u-boot.img, 272and sysfw.itb over tftp and then flash those to OSPI at their respective 273addresses. 274 275=> sf probe 276=> tftp ${loadaddr} tiboot3.bin 277=> sf update $loadaddr 0x0 $filesize 278=> tftp ${loadaddr} tispl.bin 279=> sf update $loadaddr 0x80000 $filesize 280=> tftp ${loadaddr} u-boot.img 281=> sf update $loadaddr 0x280000 $filesize 282=> tftp ${loadaddr} sysfw.itb 283=> sf update $loadaddr 0x6C0000 $filesize 284 285Flash layout for OSPI: 286 287 0x0 +----------------------------+ 288 | ospi.tiboot3(512K) | 289 | | 290 0x80000 +----------------------------+ 291 | ospi.tispl(2M) | 292 | | 293 0x280000 +----------------------------+ 294 | ospi.u-boot(4M) | 295 | | 296 0x680000 +----------------------------+ 297 | ospi.env(128K) | 298 | | 299 0x6A0000 +----------------------------+ 300 | ospi.env.backup (128K) | 301 | | 302 0x6C0000 +----------------------------+ 303 | ospi.sysfw(1M) | 304 | | 305 0x7C0000 +----------------------------+ 306 | padding (256k) | 307 0x800000 +----------------------------+ 308 | ospi.rootfs(UBIFS) | 309 | | 310 +----------------------------+ 311 312Kernel Image and DT are expected to be present in the /boot folder of UBIFS 313ospi.rootfs just like in SD card case. U-Boot looks for UBI volume named 314"rootfs" for rootfs. 315 316To boot kernel from OSPI, at the U-Boot prompt: 317=> setenv boot ubi 318=> boot 319 320UART: 321----- 322ROM supports booting from MCU_UART0 via X-Modem protocol. The entire UART-based 323boot process up to U-Boot (proper) prompt goes through different stages and uses 324different UART peripherals as follows: 325 326 WHO | Loading WHAT | HW Module | Protocol 327----------+---------------+-------------+------------ 328Boot ROM | tiboot3.bin | MCU_UART0 | X-Modem(*) 329R5 SPL | sysfw.itb | MCU_UART0 | Y-Modem(*) 330R5 SPL | tispl.bin | MAIN_UART0 | Y-Modem 331A53 SPL | u-boot.img | MAIN_UART0 | Y-Modem 332 333(*) Note that in addition to X/Y-Modem related protocol timeouts the DMSC 334 watchdog timeout of 3min (typ.) needs to be observed until System Firmware 335 is fully loaded (from sysfw.itb) and started. 336 337Example bash script sequence for running on a Linux host PC feeding all boot 338artifacts needed to the device: 339 340MCU_DEV=/dev/ttyUSB1 341MAIN_DEV=/dev/ttyUSB0 342 343stty -F $MCU_DEV 115200 cs8 -cstopb -parenb 344stty -F $MAIN_DEV 115200 cs8 -cstopb -parenb 345 346sb --xmodem tiboot3.bin > $MCU_DEV < $MCU_DEV 347sb --ymodem sysfw.itb > $MCU_DEV < $MCU_DEV 348sb --ymodem tispl.bin > $MAIN_DEV < $MAIN_DEV 349sleep 1 350sb --xmodem u-boot.img > $MAIN_DEV < $MAIN_DEV 351