1Allwinner 64-bit boards README 2============================== 3 4Newer Allwinner SoCs feature ARMv8 cores (ARM Cortex-A53) with support for 5both the 64-bit AArch64 mode and the ARMv7 compatible 32-bit AArch32 mode. 6Examples are the Allwinner A64 (used for instance on the Pine64 board) or 7the Allwinner H5 SoC (as used on the OrangePi PC 2). 8These SoCs are wired to start in AArch32 mode on reset and execute 32-bit 9code from the Boot ROM (BROM). As this has some implications on U-Boot, this 10file describes how to make full use of the 64-bit capabilities. 11 12Quick Start / Overview 13====================== 14- Build the ARM Trusted Firmware binary (see "ARM Trusted Firmware (ATF)" below) 15- Build U-Boot (see "SPL/U-Boot" below) 16- Transfer to an uSD card (see "microSD card" below) 17- Boot and enjoy! 18 19Building the firmware 20===================== 21 22The Allwinner A64/H5 firmware consists of three parts: U-Boot's SPL, an 23ARM Trusted Firmware (ATF) build and the U-Boot proper. 24The SPL will load both ATF and U-Boot proper along with the right device 25tree blob (.dtb) and will pass execution to ATF (in EL3), which in turn will 26drop into the U-Boot proper (in EL2). 27As the ATF binary will become part of the U-Boot image file, you will need 28to build it first. 29 30 ARM Trusted Firmware (ATF) 31---------------------------- 32Checkout the "allwinner" branch from the github repository [1] and build it: 33$ export CROSS_COMPILE=aarch64-linux-gnu- 34$ make PLAT=sun50iw1p1 DEBUG=1 bl31 35The resulting binary is build/sun50iw1p1/debug/bl31.bin. Either put the 36location of this file into the BL31 environment variable or copy this to 37the root of your U-Boot build directory (or create a symbolic link). 38$ export BL31=/src/arm-trusted-firmware/build/sun50iw1p1/debug/bl31.bin 39 (adjust the actual path accordingly) 40 41 SPL/U-Boot 42------------ 43Both U-Boot proper and the SPL are using the 64-bit mode. As the boot ROM 44enters the SPL still in AArch32 secure SVC mode, there is some shim code to 45enter AArch64 very early. The rest of the SPL runs in AArch64 EL3. 46U-Boot proper runs in EL2 and can load any AArch64 code (using the "go" 47command), EFI applications (with "bootefi") or arm64 Linux kernel images 48(often named "Image"), using the "booti" command. 49 50$ make clean 51$ export CROSS_COMPILE=aarch64-linux-gnu- 52$ make pine64_plus_defconfig 53$ make 54 55This will build the SPL in spl/sunxi-spl.bin and a FIT image called u-boot.itb, 56which contains the rest of the firmware. 57 58 59Boot process 60============ 61The on-die BROM code will try several methods to load and execute the firmware. 62On a typical board like the Pine64 this will result in the following boot order: 63 641) Reading 32KB from sector 16 (@8K) of the microSD card to SRAM A1. If the 65BROM finds the magic "eGON" header in the first bytes, it will execute that 66code. If not (no SD card at all or invalid magic), it will: 672) Try to read 32KB from sector 16 (@8K) of memory connected to the MMC2 68controller, typically an on-board eMMC chip. If there is no eMMC or it does 69not contain a valid boot header, it will: 703) Initialize the SPI0 controller and try to access a NOR flash connected to 71it (using the CS0 pin). If a flash chip is found, the BROM will load the 72first 32KB (from offset 0) into SRAM A1. Now it checks for the magic eGON 73header and checksum and will execute the code upon finding it. If not, it will: 744) Initialize the USB OTG controller and will wait for a host to connect to 75it, speaking the Allwinner proprietary (but deciphered) "FEL" USB protocol. 76 77 78To boot the Pine64 board, you can use U-Boot and any of the described methods. 79 80FEL boot (USB OTG) 81------------------ 82FEL is the name of the Allwinner defined USB boot protocol built in the 83mask ROM of most Allwinner SoCs. It allows to bootstrap a board solely 84by using the USB-OTG interface and a host port on another computer. 85As the FEL mode is controlled by the boot ROM, it expects to be running in 86AArch32. For now the AArch64 SPL cannot properly return into FEL mode, so the 87feature is disabled in the configuration at the moment. 88 89microSD card 90------------ 91Transfer the SPL and the U-Boot FIT image directly to an uSD card: 92# dd if=spl/sunxi-spl.bin of=/dev/sdx bs=8k seek=1 93# dd if=u-boot.itb of=/dev/sdx bs=8k seek=5 94# sync 95(replace /dev/sdx with you SD card device file name, which could be 96/dev/mmcblk[x] as well). 97 98Alternatively you can concatenate the SPL and the U-Boot FIT image into a 99single file and transfer that instead: 100$ cat spl/sunxi-spl.bin u-boot.itb > u-boot-sunxi-with-spl.bin 101# dd if=u-boot-sunxi-with-spl.bin of=/dev/sdx bs=8k seek=1 102 103You can partition the microSD card, but leave the first MB unallocated (most 104partitioning tools will do this anyway). 105 106NOR flash 107--------- 108Some boards (like the SoPine, Pinebook or the OrangePi PC2) come with a 109soldered SPI NOR flash chip. On other boards like the Pine64 such a chip 110can be connected to the SPI0/CS0 pins on the PI-2 headers. 111Create the SPL and FIT image like described above for the SD card. 112Now connect either an "A to A" USB cable to the upper USB port on the Pine64 113or get an adaptor and use a regular A-microB cable connected to it. Other 114boards often have a proper micro-B USB socket connected to the USB OTB port. 115Remove a microSD card from the slot and power on the board. 116On your host computer download and build the sunxi-tools package[2], then 117use "sunxi-fel" to access the board: 118$ ./sunxi-fel ver -v -p 119This should give you an output starting with: AWUSBFEX soc=00001689(A64) ... 120Now use the sunxi-fel tool to write to the NOR flash: 121$ ./sunxi-fel spiflash-write 0 spl/sunxi-spl.bin 122$ ./sunxi-fel spiflash-write 32768 u-boot.itb 123Now boot the board without an SD card inserted and you should see the 124U-Boot prompt on the serial console. 125 126(Legacy) boot0 method 127--------------------- 128boot0 is Allwiner's secondary program loader and it can be used as some kind 129of SPL replacement to get U-Boot up and running from an microSD card. 130For some time using boot0 was the only option to get the Pine64 booted. 131With working DRAM init code in U-Boot's SPL this is no longer necessary, 132but this method is described here for the sake of completeness. 133Please note that this method works only with the boot0 files shipped with 134A64 based boards, the H5 uses an incompatible layout which is not supported 135by this method. 136 137The boot0 binary is a 32 KByte blob and contained in the official Pine64 images 138distributed by Pine64 or Allwinner. It can be easily extracted from a micro 139SD card or an image file: 140# dd if=/dev/sd<x> of=boot0.bin bs=8k skip=1 count=4 141where /dev/sd<x> is the device name of the uSD card or the name of the image 142file. Apparently Allwinner allows re-distribution of this proprietary code 143"as-is". 144This boot0 blob takes care of DRAM initialisation and loads the remaining 145firmware parts, then switches the core into AArch64 mode. 146The original boot0 code looks for U-Boot at a certain place on an uSD card 147(at 19096 KB), also it expects a header with magic bytes and a checksum. 148There is a tool called boot0img[3] which takes a boot0.bin image and a compiled 149U-Boot binary (plus other binaries) and will populate that header accordingly. 150To make space for the magic header, the pine64_plus_defconfig will make sure 151there is sufficient space at the beginning of the U-Boot binary. 152boot0img will also take care of putting the different binaries at the right 153places on the uSD card and works around unused, but mandatory parts by using 154trampoline code. See the output of "boot0img -h" for more information. 155boot0img can also patch boot0 to avoid loading U-Boot from 19MB, instead 156fetching it from just behind the boot0 binary (-B option). 157$ ./boot0img -o firmware.img -B boot0.img -u u-boot-dtb.bin -e -s bl31.bin \ 158-a 0x44008 -d trampoline64:0x44000 159Then write this image to a microSD card, replacing /dev/sdx with the right 160device file (see above): 161$ dd if=firmware.img of=/dev/sdx bs=8k seek=1 162 163[1] https://github.com/apritzel/arm-trusted-firmware.git 164[2] git://github.com/linux-sunxi/sunxi-tools.git 165[3] https://github.com/apritzel/pine64/ 166