Official sunxi OpenEmbedded layer for Allwinner-based boards.
Go to file
Jens Lucius 8f1c8f67cf fbturbo: increase version, depend libump
- increase version number to correct version (0.5.1)
- depend on libump

Signed-off-by: Jens Lucius <info@jenslucius.com>
2015-09-22 16:58:44 +02:00
classes change filesystem from ext3 to ext4 2015-09-21 14:32:41 +02:00
conf Merge pull request #108 from Noxenious/master 2015-08-10 16:38:31 +02:00
recipes-bsp update to latest sunxi-board-fex 2015-09-21 14:34:35 +02:00
recipes-devtools/python pyA20: Add more olimex boards 2015-03-02 16:39:10 +01:00
recipes-graphics fbturbo: increase version, depend libump 2015-09-22 16:58:44 +02:00
recipes-kernel/linux adjust git kernel version 2015-09-21 16:59:07 +02:00
recipes-multimedia/gstreamer gst-plugin-cedar: import PoC gstreamer 0.10 plugin 2014-01-16 13:52:23 +01:00
recipes-support/sunxi-tools update sunxi-tools 2015-09-21 15:54:00 +02:00
COPYING.MIT allwinner-a10: initial import. 2012-06-03 19:47:57 +02:00
README.md Fix Typos in README.md 2015-07-16 22:46:03 +02:00

meta-sunxi

Official sunxi OpenEmbedded layer for Allwinner-based boards.

This layer depends on the additional layer:

meta-openembedded: git://git.openembedded.org/meta-openembedded

Tested with core-image-base.

Maintainers:

Kernel / U-Boot Version

Most Allwinner devices and hardware are supported in mainline kernel and U-Boot, so this layer builds mainline by default. There is a custom U-Boot and Kernel version for sunxi devices which includes some special drivers not mainlined. These versions are rather old (3.4 for kernel and 2014.04 for U-Boot), but may support more functions and devices than current mainline

If you want to switch back to sunxi versions for some reasons (no device tree available, unsupported hardware), change the file /conf/machine/include/sunxi.inc and set

PREFERRED_PROVIDER_u-boot="u-boot-sunxi"
PREFERRED_PROVIDER_virtual/bootloader="u-boot-sunxi"
PREFERRED_PROVIDER_virtual/kernel="linux-sunxi"

If you already have built the mainline versions it might be necessary to reset the build directories with:

bitbake -c clean linux
bitbake -c clean u-boot

Performance

The default machine settings are meant to be the lowest common denominator, maximizing generality. Significantly better performance (2x-3x) can be achieved with the following settings:

Allwinner A20

For Allwinner A20 (Cubieboard2/CubieTruck), the following tuning options are recommended:

Enable hardfloat, thumb2 and neon capabilities

DEFAULTTUNE = "cortexa7hf-neon-vfpv4"

This tuning profile takes advantage of the Allwinner A20 hardfloat, neon and vfpv4 capabilities.

Change CPU governor to ondemand, and tune settings

echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo 336000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
echo 912000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
#More aggressive
#echo 1008000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 40 > /sys/devices/system/cpu/cpufreq/ondemand/up_threshold
echo 200000 > /sys/devices/system/cpu/cpufreq/ondemand/sampling_rate

This code changes the default CPU governor from fantasy to ondemand, and tunes its settings, as recommended at http://linux-sunxi.org/Cpufreq

For additional discussion, see https://github.com/linux-sunxi/meta-sunxi/issues/25