board/sunxi/README.sunxi64 - u-boot-mtk - Git at Google

 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)
   $ cd /src/arm-trusted-firmware
   $ make PLAT=sun50i_a64 DEBUG=1 bl31
 - Build U-Boot (see "SPL/U-Boot" below)
   $ export BL31=/path/to/bl31.bin
   $ make pine64_plus_defconfig && make -j5
 - Transfer to an uSD card (see "microSD card" below)
   $ dd if=u-boot-sunxi-with-spl.bin of=/dev/sdx bs=8k seek=1
 - 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 latest master branch from the official ATF repository [1] and
 build it:
 $ export CROSS_COMPILE=aarch64-linux-gnu-
 $ make PLAT=sun50i_a64 DEBUG=1 bl31
 The resulting binary is build/sun50i_a64/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/sun50i_a64/debug/bl31.bin
   (adjust the actual path accordingly)
 The platform target "sun50i_a64" covers all boards with either an Allwinner
 A64 or H5 SoC (since they are very similar). For boards with an Allwinner H6
 SoC use "sun50i_h6".

 If you run into size issues with the resulting U-Boot image file, it might
 help to use a release build, by using "DEBUG=0" when building bl31.bin.
 As sometimes the ATF build process is a bit picky about the toolchain used,
 or if you can't be bothered with building ATF, there are known working
 binaries in the firmware repository[3], purely for convenience reasons.

  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. u-boot-sunxi-with-spl.bin joins those
 two components in one convenient image file.


 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.
 The repository in [3] contains FEL capable SPL binaries, built using an
 off-tree branch to generate 32-bit ARM code (along with instructions
 how to re-create them).

 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 use the SPL and the U-Boot FIT image combined into a
 single file and transfer that instead:
 # 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 Allwinner'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/ARM-software/arm-trusted-firmware.git
 [2] git://github.com/linux-sunxi/sunxi-tools.git
 [3] https://github.com/apritzel/pine64/
	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)
	$ cd /src/arm-trusted-firmware
	$ make PLAT=sun50i_a64 DEBUG=1 bl31
	- Build U-Boot (see "SPL/U-Boot" below)
	$ export BL31=/path/to/bl31.bin
	$ make pine64_plus_defconfig && make -j5
	- Transfer to an uSD card (see "microSD card" below)
	$ dd if=u-boot-sunxi-with-spl.bin of=/dev/sdx bs=8k seek=1
	- 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 latest master branch from the official ATF repository [1] and
	build it:
	$ export CROSS_COMPILE=aarch64-linux-gnu-
	$ make PLAT=sun50i_a64 DEBUG=1 bl31
	The resulting binary is build/sun50i_a64/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/sun50i_a64/debug/bl31.bin
	(adjust the actual path accordingly)
	The platform target "sun50i_a64" covers all boards with either an Allwinner
	A64 or H5 SoC (since they are very similar). For boards with an Allwinner H6
	SoC use "sun50i_h6".

	If you run into size issues with the resulting U-Boot image file, it might
	help to use a release build, by using "DEBUG=0" when building bl31.bin.
	As sometimes the ATF build process is a bit picky about the toolchain used,
	or if you can't be bothered with building ATF, there are known working
	binaries in the firmware repository[3], purely for convenience reasons.

	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. u-boot-sunxi-with-spl.bin joins those
	two components in one convenient image file.


	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.
	The repository in [3] contains FEL capable SPL binaries, built using an
	off-tree branch to generate 32-bit ARM code (along with instructions
	how to re-create them).

	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 use the SPL and the U-Boot FIT image combined into a
	single file and transfer that instead:
	# 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 Allwinner'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/ARM-software/arm-trusted-firmware.git
	[2] git://github.com/linux-sunxi/sunxi-tools.git
	[3] https://github.com/apritzel/pine64/