Allwinner A10 & A20 boards

Overview

Both kernels are stable and production ready, but you should use them for different purposes since their basic support differ:

  • legacy: video acceleration, NAND support, connecting displays
  • mainline: headless server, office desktop operations (not multimedia oriented)

Legacy

System images with legacy kernel

  • Kernel 3.4.x with large hardware support, headers and some firmware included
  • Enabled audio devices: analog, 8 channel HDMI, spdif and I2S (if wired and enabled in HW configuration)
  • IR functional and preconfigured – tested with LG remote
  • LIRC GPIO send and receive driver – tested but unconfigured
  • Bluetooth ready (working with supported external keys)
  • Enabled overlayfs
  • I2C ready and tested with small 16×2 LCD. Basic i2c tools included.
  • SPI ready and tested with ILI9341 based 2.4″ TFT LCD display.
  • Drivers for small TFT LCD display modules.
  • Clustering / stacking
  • USB redirector – for sharing USB over TCP/IP (disabled by default /etc/init.d/rc.usbsrvd)
  • Onboard LED attached to SD card activity (script.bin)

Bugs or limitation

  • NAND install sometime fails. Workaround: install Lubuntu to NAND with Phoenix tools and run install again.
  • Shutdown results into reboot under certain conditions.

Mainline

System images with mainline kernel

  • Mainline with large hardware support, headers and some firmware included
  • Docker ready
  • Enabled audio devices: analog, SPDIF (if available) & USB
  • USB / UAS – more efficient disk access over USB (A20 and H3)
  • CAN bus – Controller Area Network
  • USB OTG connector – OTG or host mode
  • Bluetooth ready (working with supported external keys)
  • I2C ready and tested with small 16×2 LCD. Basic i2c tools included.
  • Onboard LED attached to SD card activity (not enabled on all boards yet)

Bugs or limitation

  • No HW acceleration for desktop and video decoding
  • NAND is not supported yet
  • Screen output from kernel is set to HDMI by default. Boot loader can detect and switch, kernel not.
  • HDMI audio is not supported yet
  • SATA port multiplier support is disabled by default, can be enabled by adding kernel parameter ahci_sunxi.enable_pmp=1

Desktop

YOUTUBE

  • HW accelerated video playback (legacy kernel only)
  • MALI Open GLES (legacy kernel only)
  • Pre-installed: Firefox, LibreOffice Writer, Thunderbird
  • Lightweight XFCE desktop
  • Autologin, when normal user is created – no login manager (/etc/default/nodm)

Notes

Setting non-standard monitor settings for A10, A20 and A31 based boards in u-boot

Following commands (example) needs to be executed in u-boot command prompt:

setenv video-mode sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=0,overscan_x=1,overscan_y=2
saveenv

Since environment is reset after flashing u-boot, you need to do this after every u-boot upgrade or put this to u-boot script

Resources

Armbian packages repository