meta-chai

yocto layer for lichee-pi zero (Allwinner V3s) based on mainline u-boot 2021.xx and kernel 5.x

for easy start

repo init -u [email protected]:DAMEK86/lichee-manifests.git
repo sync

How to use

For instance if you like to build variant licheepizero-dock, you can start with the following bash script:

export TEMPLATECONF=$PWD/sources/meta-nightowl/conf/variant/licheepizero-dock
source sources/poky/oe-init-build-env build

bitbake chai-image

how to use zero-dock mic

First of all, the v3s audio coded has no MIC1 bias. Instead, it looks to me like an differential input. I was able to get the mic working by changing the MIC setting from single ended to Left/Right within alsamixer.

For easy verification, use the chai-image-audio with the alsa-tools. Just plugin your headphone, setup ALSA like the picture above and run alsaloop and verify the microphone 😎️

enable/disable kernel features

depending on the enabled machine features, kernel features are added.

• alsa - sound and codec are baked in
• screen - FB are backed in
• touchscreen - PWM and Touchscreen for NS2009 (onboard) is backed in

you can add machine features by edit conf/local.conf just use MACHINE_FEATURES_append or MACHINE_FEATURES_remove

UI images

there are 2 images

chai-image-ui
qt5-image

The chai-image-ui starts htop as a example. The qt5 image instead contains an calculator example. For best user-experience, enable touchscreen support. To start the calculator, execute /opt/qt-simple-calc/simpleCalculator.

To start bad_apple on chai-image-ui, execute gst-play-1.0 --videosink=fbdevsink /usr/share/bad_apple_30.mp4

The backed in splash screen appears on first reboot or second start.

shutdown / reboot

The Zero and Zero-Dock uses an EA3036 PMIC with routed enable pins to 5V. As a result, the power consumption will not drop to zero on a shutdown. A possible workaround could be using a pin to drive a self-holding circuit. reboot instead works as expected.

u-boot / network boot

tftp

on startup you can download kernel and corresponding device-tree over tftp

setenv ipaddr <licheeip>
tftp 0x42000000 <serverip>:zImage; tftp 0x43000000 <serverip>:sun8i-v3s-licheepi-zero-dock.dtb; bootz 0x42000000 - 0x43000000"

HINT: u-boot reads unique mac from chip

as a starting point, you can use this simple script to host a local tftp server in docker

docker run --rm -it -p 69:69/udp \
    -v ${PWD}/zImage:/tftpboot/zImage:ro \
    -v ${PWD}/sun8i-v3s-licheepi-zero-dock.dtb:/tftpboot/sun8i-v3s-licheepi-zero-dock.dtb:ro \
    darkautism/k8s-tftp

this image is based on a tiny golang implementation and works very well for my purposes, see https://github.com/darkautism/k8s-tftp

network boot / nfsroot

to enable network boot, you need to enable kernel features by adding KERNEL_ENABLE_NFS = "1" to your __local.conf. after this, your kernel shall be able to mount a nfs as rootfs

use the kernel cmdline to tell the kernel we want to use a network rootfs. I used the following script in u-boot cmd for my testing:

setenv bootargs "console=ttyS0,115200 root=/dev/nfs ip=192.168.5.78:192.168.5.80:192.168.5.80:255.255.255.0:licheepizero-dock:eth0 nfsroot=192.168.5.80:/export,tcp,v3 rootwait panic=2 debug"
setenv origbootcmd "$bootcmd"
setenv ipaddr 192.168.5.78
setenv bootcmd "tftp 0x42000000 192.168.5.80:zImage; tftp 0x43000000 192.168.5.80:sun8i-v3s-licheepi-zero-dock.dtb; bootz 0x42000000 - 0x43000000"
run bootcmd

for a detailed description of nfsroot parameters see https://www.kernel.org/doc/Documentation/filesystems/nfs/nfsroot.txt

as a starting point, you can use nfs-kernel-server

as a reference have a look into https://community.arm.com/developer/tools-software/oss-platforms/w/docs/542/nfs-remote-network-userspace-using-u-boot or http://linux-sunxi.org/How_to_boot_the_A10_or_A20_over_the_network#TFTP_booting

sunxi-tools / flash boot

sunxi-tools from github can be used for u-boot / kernel developing and nor-flash programming HINT: official prebuilt packages for ubuntu/debian seems to not working on ubuntu 20.x

how to build sunxi-tools

sudo apt install libfdt-dev libusb-1.0-0-dev
git clone [email protected]:linux-sunxi/sunxi-tools.git
cd sunxi-tools
make

fel boot

sudo sunxi-tools/sunxi-fel -v uboot u-boot-sunxi-with-spl.bin \
    write 0x42000000 zImage \
    write 0x43000000 sun8i-v3s-licheepi-zero-dock.dtb \
    write 0x43100000 boot.scr

program flash and boot from fel / flash

write kernel, dtb to flash and start uboot from fel cli

sudo ./sunxi-tools/sunxi-fel \
    spiflash-write 0x0e0000 sun8i-v3s-licheepi-zero-dock-licheepizero-dock.dtb \
    spiflash-write 0x100000 zImage-licheepizero-dock.bin
sudo ./sunxi-tools/sunxi-fel uboot u-boot-sunxi-with-spl.bin

for booting from flash

sudo ./sunxi-tools/sunxi-fel spiflash-write 0x0 u-boot-sunxi-with-spl.bin

qemu target

# make sure, qemu-helper-native is bitbaked
bitbake qemu-helper-native

# Set up networking for qemu
$ sudo ../sources/poky/scripts/runqemu-gen-tapdevs 1000 1000 4 tmp/sysroots-components/x86_64/qemu-helper-native/usr/bin

# Give qemu permissions to access tun interfaces
$ sudo setcap cap_net_admin+ep $(find tmp/work/ -name qemu-system-x86_64 | grep qemu-helper-native)

# run qemu instance
runqemu nographic qemuparams="-m 256 -enable-kvm"