===== The Allwinner boot process =====

Most Allwinner systems use U-Boot as the boot program.  This page documents that process.

==== U-Boot layout ====

Recent versions of U-Boot are split into a small first-stage loader called SPL and a main boot program.  The following table shows SD Card layout expected by system ROM:

| SD Card layout |||
| start | size | usage |
| 0 | 8KB | Partition table |
| 8KB | 32KB | Initial SPL loader |
| 40KB | 512KB | U-Boot |
| 552KB | 472KB | Reserved |
| 1024KB | - | Free for partitions |

To write the u-boot files to an SD Card:

<code>
# dd if=/usr/local/share/u-boot/u-boot-<portname>/u-boot-sunxi-with-spl.bin conv=notrunc,sync of=/dev/sd_card_device bs=1k seek=8
</code>

Alternatively on 64 bits %%SoCs%% you can put u-boot in an alternate location that doesn't conflict with GPT table

<code>
# dd if=/usr/local/share/u-boot/u-boot-<portname>/u-boot-sunxi-with-spl.bin conv=sync of=/dev/sd_card_device bs=128k seek=1
</code>

==== U-boot ports ====

The main U-Boot program can be configured with many different options for loading a kernel from SD card, USB drives, SATA drives, or the network. When booting %%FreeBSD%% the usual process is to have U-Boot start **loader.efi** from the FAT partition in either EFI/boot/bootarm.efi or EFI/boot/bootaa64.efi depending on the architecture.

Some precompiled u-boot are available via ports and packages. For instance, you can simply enter ''%%pkg install u-boot-cubieboard%%'', and all the files you will need to get U-Boot onto an SD card are installed for you in ''%%/usr/local/share/u-boot%%'', including a README file that tells you how to install the file(s) onto the SD card.

The following U-Boot ports and packages are available for Allwinner systems:

  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-a13-olinuxino|sysutils/u-boot-a13-olinuxino]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-a64-olinuxino|sysutils/u-boot-a64-olinuxino]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-bananapi|sysutils/u-boot-bananapi]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-bananapim2|sysutils/u-boot-bananapim2]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-cubieboard|sysutils/u-boot-cubieboard]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-cubieboard2|sysutils/u-boot-cubieboard2]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-olimex-a20-som-evb|sysutils/u-boot-olimex-a20-som-evb]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-olinuxino-lime|sysutils/u-boot-olinuxino-lime]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-orangepi-one|sysutils/u-boot-orangepi-one]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-orangepi-pc|sysutils/u-boot-orangepi-pc]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-orangepi-pc2|sysutils/u-boot-orangepi-pc2]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-orangepi-plus-2e|sysutils/u-boot-orangepi-plus-2e]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-orangepi-zero|sysutils/u-boot-orangepi-zero]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-pcduino3|sysutils/u-boot-pcduino3]]
  * [[https://www.freshports.org/sysutils/u-boot-pine-h64|sysutils/u-boot-pine-h64]]
  * [[https://www.freshports.org/sysutils/u-boot-pine64|sysutils/u-boot-pine64]]
  * [[https://www.freshports.org/sysutils/u-boot-pine64-lts|sysutils/u-boot-pine64-lts]]
  * [[https://www.freshports.org/sysutils/u-boot-pinebook|sysutils/u-boot-pinebook]]
  * [[https://www.freshports.org/sysutils/u-boot-pinebookpro|sysutils/u-boot-pinebookpro]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-sinovoip-bpi-m3|sysutils/u-boot-sinovoip-bpi-m3]]
  * [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-sopine|sysutils/u-boot-sopine]]

Technical note: these are all slave ports of [[https://svnweb.freebsd.org/ports/head/sysutils/u-boot-master|sysutils/u-boot-master]] with some predefined variables.