mirror of
https://github.com/linux-sunxi/meta-sunxi.git
synced 2024-11-08 22:38:22 +01:00
89 lines
3.5 KiB
Markdown
89 lines
3.5 KiB
Markdown
meta-sunxi
|
|
==============
|
|
|
|
Official sunxi OpenEmbedded layer for Allwinner-based boards.
|
|
|
|
This layer depends on the additional layers:
|
|
|
|
* [meta-openembedded/meta-oe](http://git.openembedded.org/meta-openembedded/tree/meta-oe)
|
|
* [meta-arm](https://git.yoctoproject.org/meta-arm)
|
|
|
|
Tested with core-image-base.
|
|
|
|
Maintainers:
|
|
|
|
* Nicolas Aguirre <aguirre.nicolas@gmail.com>
|
|
* Enrico Butera <ebutera@users.sourceforge.net>
|
|
* Sergey Lapin <slapin@ossfans.org>
|
|
* Marek Belisko <marek.belisko@gmail.com>
|
|
|
|
Community
|
|
===========
|
|
|
|
You can reach community + ask your question on gitter: https://matrix.to/#/#meta-sunxi:gitter.im
|
|
|
|
Kernel / U-Boot Version
|
|
===========
|
|
Most Allwinner devices and hardware are supported in mainline kernel and U-Boot, so this layer builds mainline by default.
|
|
|
|
Legacy sunxi Kernel / U-Boot
|
|
-----------
|
|
|
|
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"
|
|
KERNEL_DEVICETREE = ""
|
|
|
|
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
|
|
|
|
Mainline Kernel / U-Boot
|
|
-----------
|
|
|
|
For mainline kernel we have now support for latest LTS and stable.
|
|
By default we use latest LTS. If you would like to change version please update ```PREFERRED_VERSION_linux-mainline``` in:
|
|
* [conf/machine/include/sunxi.inc](https://github.com/linux-sunxi/meta-sunxi/blob/fa0846c0eb23e3424b89acb4d5a327e921f73497/conf/machine/include/sunxi.inc#L16)
|
|
|
|
When using mainline kernel ≥ 5.2 it is now possible to use the mainline graphics drivers *lima* and *panfrost*, instead of the *mali* driver provided by ARM. To enable open source mainline graphics support add the following line in your `local.conf`:
|
|
|
|
MACHINEOVERRIDES .= ":use-mailine-graphics"
|
|
|
|
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
|
|
|
|
|