+++ /dev/null
-Pine64 board README
-====================
-
-The Pine64(+) is a single board computer equipped with an AArch64 capable ARMv8
-compliant Allwinner A64 SoC.
-This chip has ARM Cortex A-53 cores and thus can run both in AArch32
-(compatible to 32-bit ARMv7) and AArch64 modes. Upon reset the SoC starts
-in AArch32 mode and executes 32-bit code from the Boot ROM (BROM).
-This has some implications on U-Boot.
-
-Quick start
-============
-- Get hold of a boot0.img file (see below for more details).
-- Get the boot0img tool source from the tools directory in [1] and compile
- that on your host.
-- Build U-Boot:
-$ export CROSS_COMPILE=aarch64-linux-gnu-
-$ make pine64_plus_defconfig
-$ make
-- You also need a compiled ARM Trusted Firmware (ATF) binary. Checkout the
- "allwinner" branch from the github repository [2] and build it:
-$ export CROSS_COMPILE=aarch64-linux-gnu-
-$ make PLAT=sun50iw1p1 DEBUG=1 bl31
- The resulting binary is build/sun50iw1p1/debug/bl31.bin.
-
-Now put an empty (or disposable) micro SD card in your card reader and learn
-its device file name, replacing /dev/sd<x> below with the result (that could
-be /dev/mmcblk<x> as well):
-
-$ ./boot0img --device /dev/sd<x> -e -u u-boot.bin -B boot0.img \
- -d trampoline64:0x44000 -s bl31.bin -a 0x44008 -p 100
-(either copying the respective files to the working directory or specifying
-the paths directly)
-
-This will create a new partition table (with a 100 MB FAT boot partition),
-copies boot0.img, ATF and U-Boot to the proper locations on the SD card and
-will fill in the magic Allwinner header to be recognized by boot0.
-Prefix the above call with "sudo" if you don't have write access to the
-uSD card. You can also use "-o output.img" instead of "--device /dev/sd<x>"
-to create an image file and "dd" that to the uSD card.
-Omitting the "-p" option will skip the partition table.
-
-Now put this uSD card in the board and power it on. You should be greeted by
-the U-Boot prompt.
-
-
-Main U-Boot
-============
-The main U-Boot proper is a real 64-bit ARMv8 port and runs entirely in the
-64-bit AArch64 mode. It can load any AArch64 code, EFI applications or arm64
-Linux kernel images (often named "Image") using the booti command.
-Launching 32-bit code and kernels is technically possible, though not without
-drawbacks (or hacks to avoid them) and currently not implemented.
-
-SPL support
-============
-The main task of the SPL support is to bring up the DRAM controller and make
-DRAM actually accessible. At the moment there is no documentation or source
-code available which would do this.
-There are currently two ways to overcome this situation: using a tainted 32-bit
-SPL (involving some hacks and resulting in a non-redistributable binary, thus
-not described here) or using the Allwinner boot0 blob.
-
-boot0 method
--------------
-boot0 is Allwiner's secondary program loader and it can be used as some kind
-of SPL replacement to get U-Boot up and running.
-The binary is a 32 KByte blob and contained on every Pine64 image distributed
-so far. It can be easily extracted from a micro SD card or an image file:
-# dd if=/dev/sd<x> of=boot0.bin bs=8k skip=1 count=4
-where /dev/sd<x> is the device name of the uSD card or the name of the image
-file. Apparently Allwinner allows re-distribution of this proprietary code
-as-is.
-For the time being this boot0 blob is the only redistributable way of making
-U-Boot work on the Pine64. Beside loading the various parts of the (original)
-firmware it also switches the core into AArch64 mode.
-The original boot0 code looks for U-Boot at a certain place on an uSD card
-(at 19096 KB), also it expects a header with magic bytes and a checksum.
-There is a tool called boot0img[1] which takes a boot0.bin image and a compiled
-U-Boot binary (plus other binaries) and will populate that header accordingly.
-To make space for the magic header, the pine64_plus_defconfig will make sure
-there is sufficient space at the beginning of the U-Boot binary.
-boot0img will also take care of putting the different binaries at the right
-places on the uSD card and works around unused, but mandatory parts by using
-trampoline code. See the output of "boot0img -h" for more information.
-boot0img can also patch boot0 to avoid loading U-Boot from 19MB, instead
-fetching it from just behind the boot0 binary (-B option).
-
-FEL boot
-=========
-FEL is the name of the Allwinner defined USB boot protocol built-in the
-mask ROM of most Allwinner SoCs. It allows to bootstrap a board solely
-by using the USB-OTG interface and a host port on another computer.
-Since FEL boot does not work with boot0, it requires the libdram hack, which
-is not described here.
-
-[1] https://github.com/apritzel/pine64/
-[2] https://github.com/apritzel/arm-trusted-firmware.git
--- /dev/null
+Allwinner 64-bit boards README
+==============================
+
+Newer Allwinner SoCs feature ARMv8 cores (ARM Cortex-A53) with support for
+both the 64-bit AArch64 mode and the ARMv7 compatible 32-bit AArch32 mode.
+Examples are the Allwinner A64 (used for instance on the Pine64 board) or
+the Allwinner H5 SoC (as used on the OrangePi PC 2).
+These SoCs are wired to start in AArch32 mode on reset and execute 32-bit
+code from the Boot ROM (BROM). As this has some implications on U-Boot, this
+file describes how to make full use of the 64-bit capabilities.
+
+Quick Start / Overview
+======================
+- Build the ARM Trusted Firmware binary (see "ARM Trusted Firmware (ATF)" below)
+- Build U-Boot (see "SPL/U-Boot" below)
+- Transfer to an uSD card (see "microSD card" below)
+- Boot and enjoy!
+
+Building the firmware
+=====================
+
+The Allwinner A64/H5 firmware consists of three parts: U-Boot's SPL, an
+ARM Trusted Firmware (ATF) build and the U-Boot proper.
+The SPL will load both ATF and U-Boot proper along with the right device
+tree blob (.dtb) and will pass execution to ATF (in EL3), which in turn will
+drop into the U-Boot proper (in EL2).
+As the ATF binary will become part of the U-Boot image file, you will need
+to build it first.
+
+ ARM Trusted Firmware (ATF)
+----------------------------
+Checkout the "allwinner" branch from the github repository [1] and build it:
+$ export CROSS_COMPILE=aarch64-linux-gnu-
+$ make PLAT=sun50iw1p1 DEBUG=1 bl31
+The resulting binary is build/sun50iw1p1/debug/bl31.bin. Either put the
+location of this file into the BL31 environment variable or copy this to
+the root of your U-Boot build directory (or create a symbolic link).
+$ export BL31=/src/arm-trusted-firmware/build/sun50iw1p1/debug/bl31.bin
+ (adjust the actual path accordingly)
+
+ SPL/U-Boot
+------------
+Both U-Boot proper and the SPL are using the 64-bit mode. As the boot ROM
+enters the SPL still in AArch32 secure SVC mode, there is some shim code to
+enter AArch64 very early. The rest of the SPL runs in AArch64 EL3.
+U-Boot proper runs in EL2 and can load any AArch64 code (using the "go"
+command), EFI applications (with "bootefi") or arm64 Linux kernel images
+(often named "Image"), using the "booti" command.
+
+$ make clean
+$ export CROSS_COMPILE=aarch64-linux-gnu-
+$ make pine64_plus_defconfig
+$ make
+
+This will build the SPL in spl/sunxi-spl.bin and a FIT image called u-boot.itb,
+which contains the rest of the firmware.
+
+
+Boot process
+============
+The on-die BROM code will try several methods to load and execute the firmware.
+On a typical board like the Pine64 this will result in the following boot order:
+
+1) Reading 32KB from sector 16 (@8K) of the microSD card to SRAM A1. If the
+BROM finds the magic "eGON" header in the first bytes, it will execute that
+code. If not (no SD card at all or invalid magic), it will:
+2) Try to read 32KB from sector 16 (@8K) of memory connected to the MMC2
+controller, typically an on-board eMMC chip. If there is no eMMC or it does
+not contain a valid boot header, it will:
+3) Initialize the SPI0 controller and try to access a NOR flash connected to
+it (using the CS0 pin). If a flash chip is found, the BROM will load the
+first 32KB (from offset 0) into SRAM A1. Now it checks for the magic eGON
+header and checksum and will execute the code upon finding it. If not, it will:
+4) Initialize the USB OTG controller and will wait for a host to connect to
+it, speaking the Allwinner proprietary (but deciphered) "FEL" USB protocol.
+
+
+To boot the Pine64 board, you can use U-Boot and any of the described methods.
+
+FEL boot (USB OTG)
+------------------
+FEL is the name of the Allwinner defined USB boot protocol built in the
+mask ROM of most Allwinner SoCs. It allows to bootstrap a board solely
+by using the USB-OTG interface and a host port on another computer.
+As the FEL mode is controlled by the boot ROM, it expects to be running in
+AArch32. For now the AArch64 SPL cannot properly return into FEL mode, so the
+feature is disabled in the configuration at the moment.
+
+microSD card
+------------
+Transfer the SPL and the U-Boot FIT image directly to an uSD card:
+# dd if=spl/sunxi-spl.bin of=/dev/sdx bs=8k seek=1
+# dd if=u-boot.itb of=/dev/sdx bs=8k seek=5
+# sync
+(replace /dev/sdx with you SD card device file name, which could be
+/dev/mmcblk[x] as well).
+
+Alternatively you can concatenate the SPL and the U-Boot FIT image into a
+single file and transfer that instead:
+$ cat spl/sunxi-spl.bin u-boot.itb > u-boot-sunxi-with-spl.bin
+# dd if=u-boot-sunxi-with-spl.bin of=/dev/sdx bs=8k seek=1
+
+You can partition the microSD card, but leave the first MB unallocated (most
+partitioning tools will do this anyway).
+
+NOR flash
+---------
+Some boards (like the SoPine, Pinebook or the OrangePi PC2) come with a
+soldered SPI NOR flash chip. On other boards like the Pine64 such a chip
+can be connected to the SPI0/CS0 pins on the PI-2 headers.
+Create the SPL and FIT image like described above for the SD card.
+Now connect either an "A to A" USB cable to the upper USB port on the Pine64
+or get an adaptor and use a regular A-microB cable connected to it. Other
+boards often have a proper micro-B USB socket connected to the USB OTB port.
+Remove a microSD card from the slot and power on the board.
+On your host computer download and build the sunxi-tools package[2], then
+use "sunxi-fel" to access the board:
+$ ./sunxi-fel ver -v -p
+This should give you an output starting with: AWUSBFEX soc=00001689(A64) ...
+Now use the sunxi-fel tool to write to the NOR flash:
+$ ./sunxi-fel spiflash-write 0 spl/sunxi-spl.bin
+$ ./sunxi-fel spiflash-write 32768 u-boot.itb
+Now boot the board without an SD card inserted and you should see the
+U-Boot prompt on the serial console.
+
+(Legacy) boot0 method
+---------------------
+boot0 is Allwiner's secondary program loader and it can be used as some kind
+of SPL replacement to get U-Boot up and running from an microSD card.
+For some time using boot0 was the only option to get the Pine64 booted.
+With working DRAM init code in U-Boot's SPL this is no longer necessary,
+but this method is described here for the sake of completeness.
+Please note that this method works only with the boot0 files shipped with
+A64 based boards, the H5 uses an incompatible layout which is not supported
+by this method.
+
+The boot0 binary is a 32 KByte blob and contained in the official Pine64 images
+distributed by Pine64 or Allwinner. It can be easily extracted from a micro
+SD card or an image file:
+# dd if=/dev/sd<x> of=boot0.bin bs=8k skip=1 count=4
+where /dev/sd<x> is the device name of the uSD card or the name of the image
+file. Apparently Allwinner allows re-distribution of this proprietary code
+"as-is".
+This boot0 blob takes care of DRAM initialisation and loads the remaining
+firmware parts, then switches the core into AArch64 mode.
+The original boot0 code looks for U-Boot at a certain place on an uSD card
+(at 19096 KB), also it expects a header with magic bytes and a checksum.
+There is a tool called boot0img[3] which takes a boot0.bin image and a compiled
+U-Boot binary (plus other binaries) and will populate that header accordingly.
+To make space for the magic header, the pine64_plus_defconfig will make sure
+there is sufficient space at the beginning of the U-Boot binary.
+boot0img will also take care of putting the different binaries at the right
+places on the uSD card and works around unused, but mandatory parts by using
+trampoline code. See the output of "boot0img -h" for more information.
+boot0img can also patch boot0 to avoid loading U-Boot from 19MB, instead
+fetching it from just behind the boot0 binary (-B option).
+$ ./boot0img -o firmware.img -B boot0.img -u u-boot-dtb.bin -e -s bl31.bin \
+-a 0x44008 -d trampoline64:0x44000
+Then write this image to a microSD card, replacing /dev/sdx with the right
+device file (see above):
+$ dd if=firmware.img of=/dev/sdx bs=8k seek=1
+
+[1] https://github.com/apritzel/arm-trusted-firmware.git
+[2] git://github.com/linux-sunxi/sunxi-tools.git
+[3] https://github.com/apritzel/pine64/