Buildroot Externals for Allwinner D1 boards

This adds support for the RISC-V boards based on the Allwinner D1 SoC.

Buildroot has support for the main Nezha board, but it does not have built in support for the additional hardware on these boards. This package attempts to add support for all hardware.

Board Status

• Lichee RV Dock - licheedock_defconfig
  • Well supported.
  • Serial Console access.
• Lichee 86 Panel - lichee86panel_defconfig
  • Networking and LCD screen don't work.
  • Access shell via USB-UART interface.
• Clockwork Pi DevTerm - clockworkpi_defconfig
  • Can be used with HDMI monitor and/or external USB keyboard.
  • Networking and LCD screen don't work.
  • Hidden UART interface shows logs but is non-interactive.
• Dongshan Pi - dongshanpi_defconfig
  • External monitor fires up.
  • Still no USB so no keyboard.
  • DEBUG interface provides console. NOTE: this is on /dev/ttyACM0 instead of /dev/ttyUSB0

Kernel Notes

We're running 5.18 rc 4 on the main branch.

There is a branch allwinner_5.4 which compiles some of the interfaces with the version of kernel that these products use. If it provides better hardware support in the long run it will be moved back to mainline.

So far using the 5.4 kernel hasn't made it easier to find devices.

The 5.18 version uses boot.scr to configure the kernel so it can get the live DTC created by U-Boot. I beleive this is done so that we can get dynamic things like memory size.

The 5.4 version uses extlinux/extlinux.conf

Building an image

1. Download this package and the buildroot source in peer directories:

   +-- src
     |- buildroot
     |- buildroot_ext_lichee_rv

2. If you are running the latest LTS (2022.02) you must patch buildroot to get the correct bootloader. This is not required for 2022.05+. Assuming you're using the directory structure above:

   patch -d . -p1 < ../buildroot_ext_lichee_rv/0001-fix-sun20i-d1-spl-in-buildroot.patch 

3. Enter the buildroot directory, enable the external package, and grab a configuration.

   make BR2_EXTERNAL=~/src/buildroot_ext_lichee_rv licheedock_defconfig

   See the config names for each board listed above.

4. You will probably want to do some minimal configuration. For example adding dropbear for ssh access and nano so you don't need to use vi to edit files.

   make menuconfig

5. Build the system.

   make

6. Grab the image in output/images/sdcard.img and deploy it.

Disabling external package

1. If you want to remove the external package run make BR2_EXTERNAL= menuconfig

Lichee Dock Serial Console

If you're developing you'll want this in case you lose screen or keyboard. Get a cheap UART adapter that support 3.3 Volt logic levels. I usually buy one that has a jumper to switch between 5 and 3.3 Volts.

    <USB A CONNECTOR>

                  +------+
          | .  . |
          | .  . |
          | .  . | - GROUND
          | .  . | - TX
          | .  . | - RX
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
          | .  . |
                  +------+

    <HDMI CONNECTOR>

Remember that the TX on the board should be connected to the RX on the UART adapter, and the RX on the board should connect to the TX on the UART adapter!

Setting up wifi credentials

1. Connect to serial console

2. Generate a wpa configuration:

   
   # wpa_passphrase "MyNetwork" foobar88
   network={
           ssid="MyNetwork"
           #psk="foobar88"
           psk=67224fb26d73f404f3c12d2576bc9cb220d068318f9a44b97ad548f15d71058c
   }

3. Replace the network section of /etc/wpa_supplicant.conf on the Lichee RV.

   # cat /etc/wpa_supplicant.conf 
   ctrl_interface=/var/run/wpa_supplicant
   ap_scan=1
   
   network={
           ssid="MyNetwork"
           #psk="foobar88"
           psk=67224fb26d73f404f3c12d2576bc9cb220d068318f9a44b97ad548f15d71058c
   }

4. Reboot: /sbin/reboot

5. get the ip:

   # ifconfig
   lo        Link encap:Local Loopback  
             inet addr:127.0.0.1  Mask:255.0.0.0
             inet6 addr: ::1/128 Scope:Host
             UP LOOPBACK RUNNING  MTU:65536  Metric:1
             RX packets:0 errors:0 dropped:0 overruns:0 frame:0
             TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000 
             RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
   
   wlan0     Link encap:Ethernet  HWaddr 2C:05:47:35:8D:E1  
             inet addr:192.168.1.109  Bcast:192.168.1.255  Mask:255.255.255.0
             inet6 addr: fe80::2e05:47ff:fe35:8de1/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:28 errors:0 dropped:4 overruns:0 frame:0
             TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000 
             RX bytes:5422 (5.2 KiB)  TX bytes:1904 (1.8 KiB)