Computers/A20-OLinuXino-LIME2

1 Device information

This computer continues to be produced over the years. Because of that it's normal to have small to medium variations of the device over time to continue to be able to produce it.

While tiny variations are probably not a noticeable, at some point the chip used for the Ethernet changed two times (probably because the older one was not available anymore).

The differences and support for it in Parabola were summarized in the table below:

Revisions	Chip	Supported
A to E	Realtek RTL8211CL	Probably works
F to G2	Realtek RTL8211E PHY	Yes
H to L	Micrel KSZ9031 PHY	Work in progress: A special u-boot that is needed to make Ethernet work is available outside of Parabola in the meantime.

2 Other resources

There is a wiki page on the Lime2 and Lime2 eMMC on the linux-sunxi.org wiki.

3 Upstream status

For the supported versions:

Software	Status
Linux	(Almost) complete support in Linux.
u-boot (bootloader)	(Almost) complete support in u-boot.

The easiest way to Interact with that computer is to connect an HDMI display and an USB keyboard. This way it will be pretty similar to x86 laptops or desktop computers.

If you need to debug boot issues, you might also find it convenient to setup the UART.

For more details on how to setup the UART, see the the Adding a serial port section on the lime2 page on the linux-sunxi wiki.

Here's more details below on what user input / output peripheral work out of the box or not:

	Display	USB Keyboard	UART	USB OTG	Ethernet
Bootrom	Unsupported	Unsupported	?	FEL mode only under certain circumstances	?
U-boot (bootloader)	HDMI displays work out of the box	USB Keyboards work out of the box	Settings: 1152008N1 (from u-boot environment)	Works but needs configuration	?
Linux	Shows boot messages with loglevel=8 Works out of the box in Linux consoles	Works out of the box in Linux consoles	Settings: 1152008N1 (from /boot/extlinux/extlinux.conf)	Works but needs configuration	Works but needs usual user configuration
Systemd	N/A		Settings: 1152008N1 (from /boot/extlinux/extlinux.conf)	Works but needs configuration	Works but needs usual user configuration
OpenRC	N/A		TODO: Test it	TODO: Test it	TODO: Test it
Xorg	Work out of the box (tested with xfce4 and lightdm-gtk-greeter)		N/A
Wayland	Work out of the box (tested with weston and lightdm-gtk-greeter)		N/A

If something doesn't work as intended it may be because of some bugs which needs to be fixed.

4 Booting

The boot-rom of a typical ARM computer supports booting only from specific storage devices. See the table below for which storage devices on which you can install the boot-loader on the A20-OLinuXino-LIME2:

Storage device	Boot-loader can be installed	Accessible after boot
eMMC	yes (some models)	yes (some models)
SATA	no	yes
MicroSD	yes	yes
SPI	yes (some models)	n/a
USB flash, USB Hard drive, etc	no	yes

Note that hardware and feature support in ARM boot-loaders such as u-boot, often lags behind Linux. For example, currently:

• u-boot doesn't support all the newer ext4 filesystem features
• u-boot cannot open encrypted partitions

You may need to format your target filesystem (or re-format an existing filesystem) in a special way. The Parabola ARM installation guide explains these caveats.

5 Installation

Available bootloaders:

• uboot4extlinux-a20-olinuxino-lime2

6 Free software status

• To use it you probably need a microSD and potentially other mass storage devices. MicroSD and most of the mass storage devices (HDD, SSD, eMMC, USB keys, etc) have a firmware inside.
• The board could probably meet the RYF requirements pretty easily as as far as I know everything works with free software (including the GPU and the video decoding offload). Note that certain software configurations might be needed to use the GPU such as Wayland or configuring randr render offload in Xorg.

7 Technical references

dts	sun7i-a20-olinuxino-lime2.dts
u-boot configuration	A20-OLinuXino-Lime2_defconfig

8 See also

• A20-OLinuXino-LIME2 (eMMC)