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

see meta-nightowl

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

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 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 kernel.org

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

as a reference have a look into community.arm.com or linux-sunxi.org

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

dev.rules

/etc/udev/rules.d/50-sunxi-fel.rules

SUBSYSTEMS=="usb", ATTRS{idVendor}=="1f3a", ATTRS{idProduct}=="efe8", MODE:="0666"

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

flashing ubi image

TODO: fix /bin/sh: can't access tty; job control turned off and use overlayfs
if using tiny distro

# offset from u-boot 0x80000 (524288/1024=512K)
sunxi-fel -v -p spiflash-write 0x80000 smart-grid-image-licheepizero-dock.ubi

for booting from flash

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

erasing 16 MB flash

sf probe
sf erase 0x0 0x1000000

using NAND instead of NOR Flash

After some research, i found out that nand boot from spi isn't in u-boot.
However i found Benedikt-Alexander Mokroß openwrt port to Allwinners V3s SoC, which was a huge burst for this part.

Steps to bringup SPI-NAND:

1. build SD-Card image and burn image to SD-Card.
2. enable BOOT_DEV = "nand" and build image again.
3. copy <imagename>.ubi to SD-Card
4. (TODO until know) perare u-boot for NAND load by running u-boot-spi-nand.sh. e.g. ./u-boot-spi-nand.sh mtd0.bin u-boot-sunxi-with-spl.bin-licheepizero-dock 2048 128
5. copy mtd0.bin to SD-Card
6. boot SD-Card

linux based

# erase uboot nand section
mtd_debug erase /dev/mtd0 0x0 0x100000
# write nand
FILE=$1
mtd_debug write /dev/mtd0 0x0 $(ls -l ${FILE} | awk '{ print $5}') ${FILE}

# write ubi to mtd1
ubiformat /dev/mtd1 -f <ubi file>

u-boot based

# erase uboot nand section
mtd erase uboot
# write nand
load mmc 0:1 ${loadaddr} <u-boot-sunxi-with-spl.bin (pepared for nand)>
mtd write uboot ${loadaddr}