H3 Manual build howto

This page describes the process to combine Allwinners binary boot0, an SDK U-Boot, an SDK linux kernel and other bits together to create a useful SD-card from scratch, the basis for further hacking.

This page is only suited for H3 based devices, please look under See also for other manual build howtos.

We of course do not build a whole distribution, we only build U-Boot, the kernel and a handful of tools, and then use an existing rootfs to get a useful system. Depending on the rootfs size, you might want to use a 2GB or larger SD Card. SD-card partitioning and formatting will be taken care of later.

= Getting a cross toolchain =

For this part, you need to refer to our toolchain page.

= Installing boot0 = SDKs only ship a binary version of boot0. This is a pristine version, and needs to be seeded with information such as the debug UART, DRAM clock rates, NAND/MMC ports. Normally this is done during the packing process. This section goes through the process manually. There are 2 flavors of boot0: 1 for NAND, and 1 for SD/MMC. One will not work with the other, as boot0 loads the next stage bootloader (U-Boot) from the respective supported storage. The boot0 binary can be found under lichee/tools/pack/chips/sun8iw7p1/bin/

The following is a series of commands (ELF 64-bit) to properly prepare boot0 for usage.


 * 1) Using sun8iw7p1 "dolphin-p1" Board as an example
 * 2) Under lichee/tools/pack

cp -fv chips/sun8iw7p1/configs/dolphin-p1/sys_config.fex out/sys_config.fex
 * 1) Copy fex file

cp -fv chips/sun8iw7p1/bin/boot0_sdcard_sun8iw7p1.bin out/boot0_sdcard.fex
 * 1) Copy boot0

dos2unix out/sys_config.fex
 * 1) Fex file compiler requires fex file in CRLF format

For compiling The fex file it's preferable to use fex2bin (fexc) from sunxi-tools fex2bin out/sys_config.fex out/sys_config.bin This will give you some errors, but they are simple to fix.
 * 1) Compile fex file with fex2bin (sunxi-tools)

Continue with commands from SDK: pctools/linux/mod_update/update_boot0 out/boot0_sdcard.fex out/sys_config.bin SDMMC_CARD
 * 1) Patch sdcard boot0

You can then dd the boot0 image onto an SD card. See below for instructions.

= Building u-boot = Building U-Boot is fairly straightforward. But before building check env settings in: brandy/u-boot-2011.09/include/configs/sun8iw7p1.h -> #define CONFIG_EXTRA_ENV_SETTINGS

Then build the U-Boot binary: lichee$ cd brandy/u-boot-2011.09

u-boot-2011.09$ make sun8iw7p1_config

u-boot-2011.09$ make [...] arm-linux-gnueabi-objcopy --gap-fill=0xff -O binary u-boot u-boot.bin 'u-boot-sun8iw7p1.bin' -> '../../tools/pack/chips/sun8iw7p1/bin/u-boot-sun8iw7p1.bin'

The last line shows the U-Boot binary being copied to the packing directory. This is because the binary still needs to be seeded with information from the fex file.

The following is an example to manually patch u-boot with sys_config.bin. See the boot0 section how to prepare it:


 * 1) Under lichee/tools/pack

cp -fv chips/sun8iw7p1/bin/u-boot-sun8iw7p1.bin out/u-boot.fex
 * 1) Copy U-Boot

pctools/linux/mod_update/update_uboot out/u-boot.fex out/sys_config.bin
 * 1) Patch U-Boot

You can then dd the updated u-boot.fex (u-boot.bin) image onto an SD card. See below for instructions.

= Installing onto Storage =

SD card
Allwinner SoCs have a specific boot process, as described in the boot loader page. The on-chip BROM loads boot0 starting from sector 16, or 8 KiB. boot0 then loads u-boot starting from sector 32800, or 16400 KiB.

Each of these binaries have a specific header, which includes a magic string and a checksum. Both must be correct for the binary to be accepted and executed by the previous stage.

The following shows the process of installing boot0 and u-boot built from the H3 SDK to an SD card in /dev/mmcblk0. Note you must leave enough unused space before the first partition (40960), or u-boot may be overwritten by filesystem usage.

dd if=boot0_sdcard.fex of=/dev/sdX bs=1k seek=8
 * 1) write boot0

dd if=u-boot.fex of=/dev/sdX bs=1k seek=16400
 * 1) write u-boot

The SDK default config for u-boot only supports FAT filesystems, so you will need have a small FAT boot partition to store your kernel and other boot files.

= Building the kernel =

This is an example of how to build a minimal kernel using the internal (ELF 32-bit) 4.6.3 linaro toolchain (needs lib32-gcc-libs and lib32-zlib on a 64-bit system) :

export PATH="$PATH":/your_path_to_the_SDK/lichee/brandy/gcc-linaro/bin cd lichee/linux-3.4 mkdir output cp rootfs.cpio.gz output/ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- sun8iw7p1smp_min_defconfig make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- uImage modules make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- INSTALL_MOD_PATH=output modules_install

Now you can copy the generated uImage and modules to your SD card. = Setting up the boot partition =

= Setting up the rootfs =

Please refer to Bootable_SD_card

As a last step you need to copy the kernel modules into the newly created rootfs. Change into the top level directory of the newly created rootfs and run: mount ${cardroot} /mnt mkdir -p /mnt/lib/modules rm -rf /mnt/lib/modules/ cp -r /output/lib /mnt/ umount /mnt (Replace  with the directory you have built your kernel in as described above.)

= Boot! =

Now you should be able to unmount your SDCard filesystems, and you should be able to boot your brand new installation.

= See also =

We have Manual build howtos for all SoCs: