Download image from uConsole github. Unzip with p7zip:
$> sudo apt-get install p7zip
$> p7zip -d uConsole_CM4_v1.3g_64bit.img.7z
Find the SD card, probably at /dev/sda. Write image with dd:
sudo dd if=uConsole_CM4_v1.3g_64bit.img of=/dev/sda bs=4M conv=fsync status=progress
Mount the newly created SD card:
$> udisksctl mount -b /dev/sda2
Create an empty ssh file under /boot and add wpa_supplicant.conf for wifi. Google this if it is unclear.
And unmount at the end:
$> udisksctl unmount -b /dev/sda2
Insert the new SD card into uConsole and boot. It takes a while to boot for the first time. Don't panic. Once it boots, it asks to set up username and others.
dd only write the image, but does not take the whole SD card. run sudo raspi-config and expand the system to the whole SD disk.
Add this in /etc/udev/rules.d/99-devterm-charging.rules:
KERNEL=="axp20x-battery",
ATTR{constant_charge_current_max}="2500000",
ATTR{constant_charge_current}="2400000"
It is easy to update keyboard firmware. It now supports Fn+trackball as scrolling, which is quite nice to have.
And Volume key=volume down, Shift key+Volume key=volume up, Fn key+Volume key=mute.
If wifi reception is poor, try add this to the bottom of /boot/config.txt:
dtparam=ant2
It may or may not work, though.
Be careful of updating packages because if may render some hardwares unusable. Always keep the original SD card just in case.
$> sudo apt update
$> sudo apt upgrade