mirror of
https://github.com/linux-sunxi/meta-sunxi.git
synced 2024-11-16 18:28:23 +01:00
50 lines
1.6 KiB
Markdown
50 lines
1.6 KiB
Markdown
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:
|
|
|
|
* Nicolas Aguirre <aguirre.nicolas@gmail.com>
|
|
* Enrico Butera <ebutera@users.berlios.de>
|
|
* Sergey Lapin <slapin@ossfans.org>
|
|
|
|
|
|
|
|
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
|
|
|
|
|