Mainline U-Boot

Jump to: navigation, search

Support for sunxi devices is increasingly available from upstream U-Boot. This page describes that support. We have a separate page for the 'legacy' sunxi branch of U-Boot.

MBOX icon important.png This document is for 32bits ARM device, for ARM64 see directly board/sunxi/README.sunxi64 in uboot sources



The current U-Boot release (v2017.09) fully supports major functions (except NAND) on all the older Allwinner SoCs (A10/A10s/A13/A20/A23/A31/A31s) and has basic support for the more recent A33, A80, H3 and A64.

The next release will be v2017.11.

See also: U-Boot Release Cycle and Release Schedule.

In Progress

Next Release (v2017.11)

Development branch





v2017.03 Release branch


v2017.01 Release branch


v2016.11 Release branch

  • Hans de Goede and Ian Campbell step down as U-boot Sunxi maintainers
  • A80
    • Full SPL support
  • A64
    • USB support
  • H3
    • DRAM impedance calibration fixes


v2016.09 Release branch

  • General
    • GPIO fixes
    • PSCI rewrite in C part 2
    • NAND controller driver
    • H3/A64 Ethernet (EMAC) support


v2016.07 Release branch

  • AXP809 PMIC support
  • PSCI rewrite in C part 1


v2016.05 Release branch

  • A23
    • Support new revisions
  • A64
    • 64-bit ARMv8 port, basic support (MMC, UART, no USB, no Ethernet)
    • (basic) EFI support (allows booting EFI applications (like grub) or kernels)
  • I2C support fix for families with separate reset control
  • SID e-fuse support for A83T and H3
  • Sync up dts files with Linux kernel
  • Update compatible strings for GPIO


v2016.03 Release branch

  • PRCM i2c support
  • A83T
    • LPDDR3 support
  • H3
    • USB host support
    • PSCI (security switches included)
    • sy8106a i2c-based regulator support
    • Power off support

Exclamation.png Known problems:

  • Commit c32a6fd breaks MII detection (and thus U-Boot networking) for sunxi GMAC.

You might observe the PHY not initializing (e.g. no LED activity), and the command mii info likely will list useless information on all available PHY slots (0x00-0x1F). Commit fc8991c fixes it again, but unfortunately that means U-Boot release v2016.03 is affected.


v2016.01 Release branch

  • sun8i-H3 support


v2015.10 Release branch

  • Console/display output
  • ANX9804 LCD-eDP bridge chip support
  • Composite video output support
  • NAND SPL driver
  • Boards
    • Olimex A20-SOM-EVB
    • A10s-Wobo-i5 (settop box)
    • Point of View pov protab2-ips9 tablet
    • Auxtek-T003 HDMI stick
    • A10 tablets based on the iNet-tek iNet-1 mainboard (e.g. Point of View Protab2 XXL, Cherry M1007)
    • A10 tablets based on the inet9f-rev03 mainboard (e.g. qware tb-g100 tablet)
    • A13 tablets based on on the inet98v_rev2 mainboard
    • A10 tablets based on the inet97fv2 mainboard
    • A23 tablets based on the gt90h-v4 mainboard


v2015.07 Release branch

  • Serial number support
  • Device model support
    • Ethernet
    • GPIO
  • sun8i (A33) support (including SPL)
  • sun9i (A80) basic support
    • UART
    • MMC
  • sun6i/sun8i
    • PSCI CPU hotplugging
  • SPL


v2015.04 Release branch

  • sun7i (A20) PSCI CPU hotplug
  • sun8i (A23) SPL
    • RSB
    • AXP223
  • sun9i (A80) basic support
    • Clocks
    • RSB
  • Console/display output
    • VGA via internal DAC
    • VGA via external DAC on LCD interface
    • LVDS
    • SSD2828 MIPI bridge
    • tl059wv5c0 LCD panel


v2015.01 Release branch

  • sun6i (A31) processor support
    • P2WI
    • AXP221
    • SPL
    • GMAC
  • sun8i (A23) processor support (no SPL)
  • sun6i/sun8i reset support
  • Console/display output
    • HDMI only
    • simplefb


v2014.10 Release branch

  • sun4i (AKA A10) and sun5i (AKA A10s and A13) processors
  • EMAC Ethernet
  • AXP152 and AXP209 power controllers
  • SMP support for sun7i via PSCI.


v2014.07 Release branch

Supported Devices

Beware: some of the above might only be supported in the latest development version.

Compile U-Boot

Get a toolchain

If you haven't done so before, get a suitable toolchain installed and added to your PATH.

Get the Device-tree Compiler

Depending on your desired U-Boot version, a sufficiently up-to-date dtc may be required. (The build process will error on an outdated dtc, and request you to upgrade it.) The installation of dtc is described in the Device tree article.

If you are going to build a Linux kernel alongside U-Boot, it might also be worth to examine the kernel sources - as they come with dtc included under ${KERNEL_DIR}/scripts/dtc/.

Clone the repository

You can clone the u-boot repository by running:

git clone git://

MBOX icon important.png You should prefer using a stable release, unless you're testing recently added boards or experimental features that have not yet made into stable release:
 git checkout v2016.01 # or whatever is latest

Determine build target

Go to your u-boot tree and search in the directory configs/ for your board, the file name looks like <board_name>_defconfig.

So, if your device is Cubieboard2 your build target is Cubieboard2_defconfig.


When you have determined what <board_name> you want to build, configure:

make CROSS_COMPILE=arm-linux-gnueabihf- <board_name>_defconfig

There is also menuconfig to play with settings if you feel like it:

make CROSS_COMPILE=arm-linux-gnueabihf- menuconfig

Then just build it:

make CROSS_COMPILE=arm-linux-gnueabihf-

or for A64:

 make ARCH=arm CROSS_COMPILE=aarch64-linux-gnu-

(When compiling natively, omit the CROSS_COMPILE=…)

When the build has completed, there will be u-boot-sunxi-with-spl.bin available in your u-boot tree. The installation step will instruct how to install this on the installation media (e.g. a SD card), but first U-Boot needs to be configured.

Configure U-Boot

This article provides a collection of various scenarios for booting with U-Boot.


For getting these bits loaded onto the hardware, please refer to the respective howto:

Booting with boot.cmd

For booting from SD with mainline U-Boot, the recommended way is:

  • create a file boot.cmd on the first partition (also check Kernel arguments for extra 'bootargs' options):
mainline kernel sunxi-3.4 kernel
setenv bootargs console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait panic=10
load mmc 0:1 0x43000000 ${fdtfile} || load mmc 0:1 0x43000000 boot/${fdtfile}
load mmc 0:1 0x42000000 uImage || load mmc 0:1 0x42000000 boot/uImage
bootm 0x42000000 - 0x43000000
setenv bootm_boot_mode sec
setenv bootargs console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait panic=10
load mmc 0:1 0x43000000 script.bin || load mmc 0:1 0x43000000 boot/script.bin
load mmc 0:1 0x42000000 uImage || load mmc 0:1 0x42000000 boot/uImage
bootm 0x42000000
  • If you also want to use an initramfs, please refer to the Initial Ramdisk article for details.
Information.png If you're wondering why setting bootm_boot_mode might be necessary for older kernels, have a look at the details of PSCI.
Sticky-note-pin.png Note: Directly using a zImage is also supported by U-Boot for the sunxi platform. Substitute zImage in place of uImage in the commands above, and then use the bootz command instead of bootm.

Booting with extlinux.conf

Mainline U-Boot also use syslinux/extlinux as payload.

You need to install the boot configuration file extlinux.conf in an ext2/3/4 partition of SD card and U-Boot will find and execute it. This is conceptually identical to creating a GRUB configuration file on a desktop PC.

Example extlinux.conf:

DEFAULT default
MENU TITLE Boot menu

LABEL default
        LINUX /zImage
        FDT /sun4i-a10-marsboard.dtb
        APPEND root=/dev/sda1 rootwait console=tty0 console=ttyS0,115200n8

LABEL exit
	MENU LABEL Local boot script (boot.scr)
        LOCALBOOT 1

Setting u-boot environment variables

There is a difference in setting environment variables between the boot script and the U-Boot shell.

Inside the shell you would set, for instance:

setenv root /dev/sda1

But in the script you would use:



Example U-Boot environment, as found in uEnv.txt from a stock android U-Boot environment partition

bootcmd=run setargs boot_normal
setargs=setenv bootargs console=${console} root=${nand_root} init=${init} loglevel=${loglevel}
boot_normal=nand read 40007800 boot;boota 40007800
boot_recovery=nand read 40007800 recovery;boota 40007800


Recent version of U-Boot are able to boot from NFS as well as TFTP, but you have to get rid of the automatic setup of FTP. Check Ethernet for more information.

Sticky-note-pin.png Note: on the A20 based cubieboards, this only seems to work on the stable kernel, not on stage.

FB console

To get U-Boot output shown on the built-in framebuffer driver (currently, HDMI only at 1024x768), add the following to your boot.cmd:

setenv stdout=serial,vga
setenv stderr=serial,vga

The default environment has these values set as well.

LCD Settings

There is a separate wiki page about configuring LCD in U-Boot.

Install U-Boot

  • Convert the boot.cmd to boot.scr using mkimage:
 mkimage -C none -A arm -T script -d boot.cmd boot.scr
  • Copy the bootloader to the installation media
 dd if=u-boot-sunxi-with-spl.bin of=/dev/sdX bs=1024 seek=8
  • copy kernel files to the first partition
    • For a 3.4 kernel you need uImage (linux kernel) and script.bin (binary representation of FEX).
    • For a device tree based kernel ("mainline", 4.x) you need the kernel image (uImage or zImage) and the device-specific .dtb file (the one referenced in the ${fdtfile} above) that is generated as part of your kernel compilation.

Look at Manual build howto for more details.


USB 1.x, USB keyboards (U-Boot < v2015.07)

U-Boot v2015.07 and later shouldn't have problems supporting mixed USB 1.x/2.0 devices. OHCI and EHCI no longer conflict with each other (after the switch to device model).

Previous U-Boot versions (v2015.04 and older) have a problem supporting both USB 1.x (OHCI) and USB 2.0 (EHCI) at the same time - the latter includes the SUNXI_EHCI driver for Allwinner boards.

Unfortunately, this also affects many USB HID / keyboard devices which would not be detected properly by U-Boot. The typical message in this case is "cannot reset port N!?", where N is whichever USB port those devices were attached to.

Information.png A possible workaround is to place an external USB 2.0 hub between your board and these USB devices.


U-Boot 2015.07+ won't start

If you're using a recent (device model based) U-Boot, and the SPL just hangs after initializing the DRAM (CPU: 912000000Hz, AXI/AHB/APB: 3/2/2 or something similar), chances are that your main U-Boot binary may be missing DTB information / a proper device tree. Depending on the (possibly outdated) instructions you followed: double-check that you're not incorrectly using u-boot.bin instead of u-boot-dtb.bin, or u-boot.img instead of u-boot-dtb.img.

Legacy kernel won't start

  • If your 3.4.x kernel refuses to boot / gets stuck right after "Starting kernel ...": Double-check that bootm_boot_mode is set to "sec"! (see above)
  • If you don't have a serial console and only use VGA/HDMI/LCD, then it might be also the case of "Unrecognized/unsupported machine ID" (see below).

Unrecognized/unsupported machine ID

The sunxi-3.4 kernel may fail to boot with one of the following error messages on the serial console (but this message is not visible on a HDMI monitor or a LCD display!):

Error: unrecognized/unsupported machine ID (r1 = 0x10001008).
Error: unrecognized/unsupported machine ID (r1 = 0x1000102a).
Error: unrecognized/unsupported machine ID (r1 = 0x100010bb).

In this case either upgrade to a recent stage/sunxi-3.4 kernel (github branch) - or try to "Enable workarounds for booting old kernels" in U-Boot:

make menuconfig or make CROSS_COMPILE=arm-linux-gnueabihf- menuconfig, the option is located under "ARM architecture". (Make sure to rebuild your U-Boot after changing it.)

If upgrading to stage/sunxi-3.4 is not an option (i.e. using some old and very much diverged sunxi-3.4 fork is really necessary), then the following patches can be cherry-picked (= selectively merged as a set):

git am 5052b83aa44dc16d6662d8d9d936166c139ad8c5.patch
git am 9a1cd034181af628d4145202289e1993c1687db6.patch
git am c4c4664ed1a2f35e54a33ae4e65f517721ff43b5.patch
git am ade08aa6e5249a9e75a97393e86c250b2bcb3ec8.patch
git am 16b25a95327f45a995f6efcf3e9d83a414231af9.patch
git am dea62f21deb177053b84b15a519dff6c74d061d9.patch
git am d47d367036be38c5180632ec8a3ad169a4593a88.patch

Exclamation.png It is required to apply all of them, as they contain important stability/safety changes. The last patch in this series only takes care of the safety guard, which exists there specifically to block booting problematic kernels. Just removing the safety guard alone without applying all the bugfixes will lead to obscure runtime problems, please don't be tempted to do this.

Adding a new device to upstream U-Boot

DRAM Settings

Failsafe DRAM settings, based on standard JEDEC timings

Each device has DRAM settings configured in its defconfig file in the U-Boot "configs" directory (here is an example for the Cubietruck board). The slow failsafe DRAM settings for an A10/A13/A20 device may look like:


A more complete set of available Kconfig options and their descriptions can be found here:;a=blob;f=board/sunxi/Kconfig;h=e1d4ab148f0838d746889775cfbab5bed57838bf;hb=a705ebc81b7f91bbd0ef7c634284208342901149#l177

The settings from the Android firmware

Somewhat better settings can be retrieved by the meminfo tool from the stock Android or GNU/Linux system, provided by the device manufacturer. It still makes sense to test the reliability of the resulting DRAM configuration. Because some vendors are providing poor configuration for ZQ or EMR1, but nevertheless trying to optimistically set the DRAM clock speed too high.

Performance optimized DRAM settings

Tuning DRAM setting for each individual board can provide much better performance than the failsafe defaults. This involves trial and error testing of different settings using a tool until an optimal combination is found. The DRAM Controller page provides links to start researching this topic. This approach will be time consuming, so a satisfactory solution using one of the other approaches may be best to start with.

See also

Personal tools