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
Please note that upstream support for kernel 3.4.x has ended in 2017 so this kernel will not receive security updates in the future.¶
- 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)
- 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
- 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¶
- 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