[PATCH] sunxi: add board documentation
Andre Przywara
andre.przywara at arm.com
Tue Dec 14 02:07:58 CET 2021
On Mon, 13 Dec 2021 18:20:37 +0100
Jernej Škrabec <jernej.skrabec at gmail.com> wrote:
Hi Jernej,
thanks for having a look!
> Dne ponedeljek, 13. december 2021 ob 02:03:22 CET je Andre Przywara
> napisal(a):
> > Add some long overdue instructions for building and installing U-Boot on
> > Allwinner SoC based boards.
> > This describes the building process, including TF-A and crust, plus
> > installation to SD card, eMMC and SPI flash, both from Linux and U-Boot
> > itself. Also describe FEL booting.
> >
> > Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> > ---
> > Hi,
> >
> > please have a look whether this makes sense. Feel free to just try
> something,
> > and point out ambiguities or missing bits. For missing topics, please
> > send a follow-up patch ;-)
>
> This documentation seems to include all of board/sunxi/README.sunxi64 and
> README.nand. I think it would make sense to remove those files. If any file gets
> out of sync for any reason, it would be very confusing for end user.
Indeed, I think README.sunxi64 is redundant now.
I didn't look at README.nand too closely, but since I don't even mention
NAND, I don't think it can be removed just yet. I guess I just convert
it to RST and move it into this directory.
> I would also remove all non-essential command parameters, so all commands are
> as simple as possible. Power users will know about them anyway and non-skilled
> users might perceive that it's harder that it really is. I have in mind "-j5 -
> s" for make, "-v -p" for sunxi-fel
I see, makes sense.
> and DEBUG=1 for TF-A (maybe I missed some
> places). Actually, DEBUG=1 could be mentioned afterwards as troubleshooting
> step. In my experience, stable version of TF-A was never source of boot issues
> nor it provided any useful information for debugging anything else.
Well, I'd tend to keep DEBUG=1 enabled, this lists the regulators
enabled, which helps debugging. Also in the past DEBUG=0 was very
silent, which wasn't helpful to verify that TF-A actually started.
Do you typically build or recommend DEBUG=0?
> Some comments bellow.
>
> >
> > Also this is quite long, shall this be split up in two (or more) files?
> >
> > This is what rst.ninjs.org made of it, if you prefer to read it formatted:
> > https://paste.c-net.org/PleasantNeedy
> >
> > Cheers,
> > Andre
> >
> > doc/board/allwinner/index.rst | 9 +
> > doc/board/allwinner/sunxi.rst | 304 ++++++++++++++++++++++++++++++++++
> > 2 files changed, 313 insertions(+)
> > create mode 100644 doc/board/allwinner/index.rst
> > create mode 100644 doc/board/allwinner/sunxi.rst
> >
> > diff --git a/doc/board/allwinner/index.rst b/doc/board/allwinner/index.rst
> > new file mode 100644
> > index 00000000000..7352ccd5c0a
> > --- /dev/null
> > +++ b/doc/board/allwinner/index.rst
> > @@ -0,0 +1,9 @@
> > +.. SPDX-License-Identifier: GPL-2.0+
> > +
> > +Allwinner (sunxi) boards
> > +========================
> > +
> > +.. toctree::
> > + :maxdepth: 2
> > +
> > + sunxi
> > diff --git a/doc/board/allwinner/sunxi.rst b/doc/board/allwinner/sunxi.rst
> > new file mode 100644
> > index 00000000000..693eb32e168
> > --- /dev/null
> > +++ b/doc/board/allwinner/sunxi.rst
> > @@ -0,0 +1,304 @@
> > +.. SPDX-License-Identifier: GPL-2.0+
> > +.. Copyright (C) 2021 Arm Ltd.
> > +
> > +Allwinner SoC based boards
> > +==========================
> > +For boards using an Allwinner ARM based SoC ("sunxi"), the U-Boot build
> > +system generates a single integrated image file: ``u-boot-sunxi-with-
> spl.bin.``
> > +This file can be used on SD cards, eMMC devices, SPI flash and for the
> > +USB-OTG based boot method (FEL). To build this file:
> > +
> > +* For 64-bit SoCs, build Trusted Firmware (TF-A, formerly known as ATF)
> first,
> > + you will need its ``bl31.bin``. See below for more details.
> > +* Optionally on 64-bit SoCs, build the crust management processor firmware.
> > +* Build U-Boot::
> > +
> > + $ export BL31=/path/to/bl31.bin # required for 64-bit SoCs
> > + $ export SCP=/src/crust/build/scp/scp.bin # optional for some 64-bit
> SoCs
>
> NIT: I guess path for SCP could be in same form, at least first part?
Yeah, makes sense.
> > + $ make <yourboardname>_defconfig
> > + $ make -j5 -s
> > +* Transfer to an uSD card (see below for more details)::
> > +
> > + $ dd if=u-boot-sunxi-with-spl.bin of=/dev/sdX bs=8k seek=1
>
> Most, if not all, distros require root for above command, so $ -> #? I see
> that you used # below. Alternative would be to prepend command with sudo,
> which is imo more beginners friendly.
Ah, good catch!
> > +* Boot and enjoy!
> > +
> > +For more details, and alternative boot locations or installations, see
> below.
> > +
> > +Building Arm Trusted Firmware (TF-A)
> > +------------------------------------
> > +Boards using a 64-bit Soc (A64, H5, H6, H616, R329) require the BL31 stage
> of
> > +the `Arm Trusted Firmware-A`_ firmware. This provides the reference
> > +implementation of secure software for Armv8-A, offering PSCI and SMCCC
> > +services. Allwinner support is fully mainlined. To build bl31.bin::
> > +
> > + $ git clone https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git
> > + $ cd trusted-firmware-a
> > + $ make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1
> > + $ export BL31=$(pwd)/build/sun50i_a64/debug/bl31.bin
> > +
> > +The target platform (``PLAT=``) for A64 and H5 SoCs is sun50i_a64, for the
> H6
> > +sun50i_h6, for the H616 sun50i_h616, and for the R329 sun50i_r329. Use::
> > +
> > + $ find plat/allwinner -name platform.mk
> > +
> > +to find all supported platforms. `docs/plat/allwinner.rst`_ contains more
> > +information and lists some build options.
> > +
> > +Building the Crust management processor firmware
> > +------------------------------------------------
> > +For some SoCs and boards, the integrated OpenRISC management controller can
> > +be used to provide power management services, foremost suspend to RAM.
> > +There is a community supported Open Source implementation called `crust`_,
> > +which runs on most SoCs featuring a management controller.
> > +
> > +This firmware part is optional, setting the SCP environment variable to
> > +/dev/null avoids the warning message when building without one.
> > +
> > +To build crust's scp.bin, you need an OpenRISC (or1k) cross compiler,
> then::
> > +
> > + $ git clone https://github.com/crust-firmware/crust.git
> > + $ cd crust
> > + $ make <yourboard>_defconfig
> > + $ make CROSS_COMPILE=or1k-none-elf- scp
>
> I guess it would be good to point out that compiler prefix may not be the same
> on all distros. For example, Arch packages this compiler and proper prefix
> there is or1k-elf- which also works just fine.
I feel I shouldn't spend too much time on this, instead just point to
crust's README.
Thanks,
Andre
>
> Best regards,
> Jernej
>
> > + $ export SCP=$(pwd)/build/scp/scp.bin
> > +
> > +Find a list of supported board configurations in the `configs/`_ directory.
> > +
> > +Building the U-Boot image
> > +-------------------------
> > +Find the U-Boot defconfig file for your board first. Those files live in
> > +the ``configs/`` directory; you can grep for the stub name of the devicetree
> > +file, if you know that, or for the SoC name to find the right version::
> > +
> > + $ git grep -l MACH_SUN8I_H3 configs
> > + $ git grep -l sun50i-h6-orangepi-3 configs
> > +
> > +The `linux-sunxi`_ wiki also lists the name of the defconfig file in the
> > +respective board page. Then use this defconfig file to create the .config
> > +file, and build the image::
> > +
> > + $ make <yourboard>_defconfig
> > + $ make -j5
> > +
> > +For 64-bit boards, this requires either the BL31 environment variable to be
> > +set (as shown above in the TF-A build example), or it to be supplied on the
> > +build command line::
> > +
> > + $ make BL31=/src/tf-a.git/build/sun50i_h616/debug/bl31.bin -j5 -s
> > +
> > +The same applies to the (optional) SCP firmware.
> > +
> > +The file containing everything you need is called ``u-boot-sunxi-with-
> spl.bin``,
> > +you will find it in the root folder of your U-Boot (build) tree. Except for
> > +raw NAND flash devices this very same file can be used for any boot source.
> > +It will contain the SPL image, fitted with the proper signature recognised
> by
> > +the BROM, and the required checksum. Also it will contain at least U-Boot
> > +proper, either wrapped in the legacy U-Boot image format, or in a FIT
> image.
> > +The board's devicetree is also included, either appended to the U-Boot
> proper
> > +image, or contained in the FIT image. If required by the SoC, this FIT file
> will
> > +also include the other firmware images.
> > +
> > +Installing U-Boot
> > +-----------------
> > +
> > +Installing on a (micro-) SD card
> > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > +All Allwinner SoCs will try to find a boot image at sector 16 (8KB) of
> > +an SD card, connected to the first MMC controller. To transfer the generated
> > +image to an SD card, from any Linux device (including the board itself)
> with
> > +an (micro-)SD card reader, type::
> > +
> > + # dd if=u-boot-sunxi-with-spl.bin of=/dev/sdX bs=1k seek=8
> > +
> > +``/dev/sdx`` needs to be replaced with the block device name of the SD card
> > +reader. On some machines this could be ``/dev/mmcblkX``.
> > +Newer SoCs (starting from H3), also look at sector 256 (128KB) for the
> > +signature (after having checked the 8KB location). Installing the firmware
> > +there has the advantage of not overlapping with a GPT partition table.
> Simply
> > +replace the "``seek=8``" above with "``seek=128``".
> > +
> > +You can also use an existing (mainline) U-Boot to write to the SD card.
> Load
> > +the generated U-Boot image somewhere into DRAM (via ``ext4load``,
> ``fatload``,
> > +or ``tftpboot``), then write to MMC device 0::
> > +
> > + => fatload mmc 0:1 $kernel_addr_r u-boot-sunxi-with-spl.bin
> > + => mmc dev 0
> > + => mmc write $kernel_addr_r 0x10 0x7f0
> > +
> > +To use the alternative boot location on newer SoCs::
> > +
> > + => mmc write $kernel_addr_r 0x100 0x700
> > +
> > +Installing on eMMC (on-board flash memory)
> > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > +Some boards have a soldered eMMC chip, some other boards have an eMMC
> socket
> > +to receive an optional eMMC module. U-Boot can be installed to those chips,
> > +to boot without an SD card inserted. The Boot-ROM can boot either from the
> > +regular user data partition, or from one of the separate eMMC boot
> partitions.
> > +U-Boot can be installed either from a running Linux instance on the device,
> > +from a running (mainline) U-Boot, or via an adapter for the (removable)
> > +eMMC module.
> > +
> > +Installing on an eMMC user data partition from Linux
> > +````````````````````````````````````````````````````
> > +If you have a running Linux instance on the device, and have somehow copied
> > +over the image file to that device, you can write the image directly into
> the
> > +eMMC device from there.
> > +Find the name of the block device file first, it is one of the
> > +``/dev/mmcblk<X>`` devices. eMMC devices typically also list a
> > +``/dev/mmcblk<X>boot0`` partition (see below), this helps you to tell it
> apart
> > +from the SD card device.
> > +To install onto the user data partition::
> > +
> > + # dd if=u-boot-sunxi-with-spl.bin of=/dev/dev/mmcblkX bs=1k seek=8
> > +
> > +Similar to SD cards, the BROM in newer SoCs (H3 and above) also checks
> > +sector 256 of an eMMC, so you can use "``seek=128``" as well.
> > +
> > +Installing on an eMMC boot partition from Linux
> > +```````````````````````````````````````````````
> > +In the following examples, ``/dev/mmcblkX`` needs to be replaced with the
> block
> > +device name of the eMMC device. The eMMC device can be recognised by also
> > +listing the boot partitions (``/dev/mmcblkXboot0``) in ``/proc/
> partitions``.
> > +
> > +To allow booting from one of the eMMC boot partitions, this one needs to be
> > +enabled first. This only needs to be done once, as this setting is
> > +persistent, even though the boot partition can be disabled or changed again
> > +any time later::
> > +
> > + # apt-get install mmc-utils
> > + # mmc bootbus set single_hs x1 x4 /dev/mmcblkX
> > + # mmc bootpart enable 1 1 /dev/mmcblkX
> > +
> > +The first "1" in the last command points to the boot partition number to be
> > +used, typically devices offer two boot partitions.
> > +
> > +By default Linux disables write access to the boot partitions, to prevent
> > +accidental overwrites. You need to disable the write protection (until the
> > +next reboot), then can write the U-Boot image to the *first* sector of the
> > +selected boot partition::
> > +
> > + # echo 0 > /sys/block/mmcblkXboot0/force_ro
> > + # dd if=u-boot-sunxi-with-spl.bin of=/dev/mmcblkXboot0 bs=1k
> > +
> > +Installing on an eMMC user data partition from U-Boot
> > +`````````````````````````````````````````````````````
> > +You can also write the generated image file to an SD card, boot the device
> > +from there, and burn the very same image to the eMMC device from U-Boot.
> > +The following commands copy the image from the SD card to the eMMC device::
> > +
> > + => mmc dev 0
> > + => mmc read $kernel_addr_r 0x10 0x7f0
> > + => mmc dev 1
> > + => mmc write $kernel_addr_r 0x10 0x7f0
> > +
> > +You can also copy an image from the 8K offset of an SD card to the 128K
> > +offset of the eMMC (or any combination), just change the "``0x10 0x7f0``"
> above
> > +to "``0x100 0x700``", respectively. Of course the image file can be loaded
> via
> > +any other loading method, including ``fatload``, ``ext4load``,
> ``tftpboot``.
> > +
> > +Installing on an eMMC boot partition from U-Boot
> > +````````````````````````````````````````````````
> > +The selected eMMC boot partition needs to be initially enabled first (same
> > +as in Linux above), you can do this from U-Boot with::
> > +
> > + => mmc dev 1
> > + => mmc bootbus 1 1 0 0
> > + => mmc partconf 1 1 1 1
> > +
> > +The first "1" in both commands denotes the MMC device number. The second "1"
> > +in the partconf command sets the required ``BOOT_ACK`` option, the last two
> "1"s
> > +selects the active boot partition and the target for the next data access,
> > +respectively. So for the next "``mmc write``" command to address one of the
> boot
> > +partitions, the last number must either be "1" or "2", "0" would switch
> (back)
> > +to the normal user data partition.
> > +
> > +Then load the ``u-boot-sunxi-with-spl.bin`` image file into DRAM, either by
> > +reading directly from an SD card or eMMC user data partition, or from a
> > +file system or TFTP (see above), and transfer it to the boot partition::
> > +
> > + => tftpboot $kernel_addr_r u-boot-sunxi-with-spl.bin
> > + => mmc write $kernel_addr_r 0 0x7f0
> > +
> > +After that the device should boot from the selected boot partition, which
> takes
> > +precedence over booting from the user data partition.
> > +
> > +Installing on SPI flash
> > +^^^^^^^^^^^^^^^^^^^^^^^
> > +Some devices have a SPI NOR flash chip soldered on the board. If it is
> > +connected to the SPI0 pins on PortC, the BROM can also boot from there.
> > +Typically the SPI flash has the lowest boot priority, so SD card and eMMC
> > +devices will be considered first.
> > +
> > +Installing on SPI flash from Linux
> > +``````````````````````````````````
> > +If the devicetree enables and describes the SPI flash device, you can access
> > +the SPI flash content from Linux, using the `MTD utils`_::
> > +
> > + # apt-get install mtd-utils
> > + # mtdinfo
> > + # mtd_debug erase /dev/mtdX 0 0xf0000
> > + # mtd_debug write /dev/mtdX 0 0xf0000 u-boot-sunxi-with-spl.bin
> > +
> > +``/dev/mtdX`` needs to be replaced with the respective device name, as
> listed
> > +in the output of ``mtdinfo``.
> > +
> > +Installing on SPI flash from U-Boot
> > +```````````````````````````````````
> > +If SPI flash driver and command support (``CONFIG_CMD_SF``) is enabled in
> the
> > +U-Boot configuration, the image file can be installed via U-Boot as well::
> > +
> > + => tftpboot $kernel_addr_r u-boot-sunxi-with-spl.bin
> > + => sf probe
> > + => sf erase 0 +0xf0000
> > + => sf write $kernel_addr_r 0 $filesize
> > +
> > +Installing on SPI flash via USB in FEL mode
> > +```````````````````````````````````````````
> > +If the device is in FEL mode (see below), the SPI flash can also be filled
> > +with the sunxi-fel utility, via an USB(-OTG) cable from any USB host
> machine::
> > +
> > + $ sunxi-fel -v -p spiflash-write 0 u-boot-sunxi-with-spl.bin
> > +
> > +Booting via the USB(-OTG) FEL mode
> > +----------------------------------
> > +If none of the boot locations checked by the BROM contain a medium or valid
> > +signature, the BROM will enter the so-called FEL mode, in which it will
> > +listen to commands from a host on the SoC's USB-OTG interface. Those
> commands
> > +allow to read from and write to arbitrary memory locations, also to start
> > +execution at any address, which allows to bootstrap a board solely via an
> > +USB cable. Some boards feature a "FEL" or "U-Boot" button, which forces
> > +FEL mode despite a valid boot location being present. The same can be
> achieved
> > +via a `magic binary`_ on an SD card, which allows to enter FEL mode on any
> > +board.
> > +
> > +To use FEL booting, let the board enter FEL mode, via any of the mentioned
> > +methods (no boot media, FEL button, SD card with FEL binary), then connect
> > +a USB cable to the board's USB OTG port. Some boards (Pine64, TV boxes)
> don't
> > +have a separate OTG port. In this case mostly one of the USB-A ports is
> > +connected to USB0, and can be used via a non-standard USB-A to USB-A cable.
> > +
> > +Typically there is no on-board indication of FEL mode, other than a new USB
> > +device appearing on the connected host computer. The USB vendor/device ID
> > +is 1f3a:efe8. Mostly this will identify as "sunxi SoC OTG connector in
> > +FEL/flashing mode", but older distributions might still report "Onda
> > +(unverified) V972 tablet in flashing mode".
> > +
> > +The `sunxi_fel`_ tool implements the proprietary BROM protocol, and allows
> to
> > +bootstrap U-Boot by just providing our venerable u-boot-sunxi-with-
> spl.bin::
> > +
> > + $ sudo apt-get install sunxi-tools
> > + $ sunxi-fel -v -p uboot u-boot-sunxi-with-spl.bin
> > +
> > +Additional binaries like a kernel, an initial ramdisk or a boot script, can
> > +also be uploaded via FEL, check the Wiki's `FEL page`_ for more details.
> > +
> > +.. _`Arm Trusted Firmware-A`: https://www.trustedfirmware.org/projects/tf-a/
> > +.. _`docs/plat/allwinner.rst`: https://trustedfirmware-a.readthedocs.io/en/
> latest/plat/allwinner.html
> > +.. _`crust`: https://github.com/crust-firmware/crust
> > +.. _`configs/`: https://github.com/crust-firmware/crust/tree/master/configs
> > +.. _`linux-sunxi`: https://linux-sunxi.org
> > +.. _`MTD utils`: http://www.linux-mtd.infradead.org/
> > +.. _`magic binary`: https://github.com/linux-sunxi/sunxi-tools/raw/master/
> bin/fel-sdboot.sunxi
> > +.. _`sunxi_fel`: https://github.com/linux-sunxi/sunxi-tools
> > +.. _`FEL page`: https://linux-sunxi.org/FEL/USBBoot
> > --
> > 2.17.6
> >
> >
>
>
>
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