Official sunxi OpenEmbedded layer for Allwinner-based boards.
Go to file
Maciej Pijanowski 628b14b9fd README.md: meta-openembedded/meta-oe as dependency
Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>
2019-05-29 19:14:33 +02:00
classes sdcard_image-sunxi.bbclass: fix dtb naming conventions 2018-11-09 23:09:54 +03:00
conf conf/layer.conf: add LAYERDEPENDS 2019-05-29 19:09:40 +02:00
recipes-bsp u-boot: upgrade to 2018.09 2018-11-10 21:58:32 +03:00
recipes-devtools/python pypi requires a https connection 2017-10-27 13:46:41 +02:00
recipes-graphics misc: Replace dri2proto with xorgproto 2019-05-27 16:26:37 +02:00
recipes-kernel recipes-kernel: xradio-firmware: Update git repository und paths 2019-02-09 21:37:20 +01:00
recipes-multimedia/gstreamer gst-plugin-cedar: import PoC gstreamer 0.10 plugin 2014-01-16 13:52:23 +01:00
recipes-support/sunxi-tools sunxi-tools: add inherit pkgconfig 2019-04-17 15:45:37 +00:00
COPYING.MIT allwinner-a10: initial import. 2012-06-03 19:47:57 +02:00
README.md README.md: meta-openembedded/meta-oe as dependency 2019-05-29 19:14:33 +02:00

meta-sunxi

Official sunxi OpenEmbedded layer for Allwinner-based boards.

This layer depends on the additional layers:

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), either:

  • change the file conf/machine/include/sunxi.inc to include the following block

  • edit your conf/local.conf to add the following block

    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 virtual/kernel virtual/bootloader

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