The latest Pi firmware has an option for a boot menu so you can boot from SD, USB or SSD.
The hotkey during boot is the .
dd CommandHow to copy from your Linux PC an image file to an SD-card.
dd bs=4M if=<image-file> of=/dev/sdX status=progress
Where bs=4M means a block size of 4 MByte is used.
Where conv=fsync means to physically write output file data before finishing also write metadata.
Where status=progress makes it show progress.
This is all done as root user of course.
Install package rpi-imager.
Run the imager and do an easy installation.
To change the hostname use the command hostnamectl.
Do not edit the file /etc/hostname.
hostnamectl set-hostname <hostname>
From the default user use sudo set the password.
sudo passwd <root-password>
See page on network manager for that.
When no graphics is needed free up resource by disabling the display manager
The display manager for Ubuntu Mate is gdm.
systemctl stop gdm.service
systemctl disable gdm.service
apt install joe mc git
First an image needs to be created from the SD-card using another system.
dd bs=<sector-size> if=/dev/sdX of=<image-file> count=<amount-sectors> status=progress
When the initial image is 7650410496 bytes and the SD is bigger then that copy should be limited.
So when the sector size is 512, the amount of sectors than is 14942208.
Resulting in:
dd bs=512 if=/dev/sdX of=<image-file> count=14942208 status=progress
dd bs=<sector-size> if=<image-file> of=/dev/mmcblkX status=progress
On the fat32 boot partition modify the file config.txt and add the following section to that file.
When the Pi is running the same file is located here /boot/formware/config.txt.
[all]
over_voltage=6
arm_freq=2000
gpu_freq=750
[all]
max_framebuffers=2
arm_freq=2900
#arm_freq_min=1000
gpu_freq=1050
over_voltage_delta=60000
Install the package kubuntu-desktop.
When the sddm service is not starting and the startx application reports an error like the following
in the log file:
VGA arbiter: cannot open kernel arbiter, no multi-card support
Create the file /etc/X11/xorg.conf.d/99-fbdev.conf having the following content.
Section "Device"
Identifier "Framebuffer"
Driver "fbdev"
Option "fbdev" "/dev/fb0"
EndSection
Enable the sddm service if not already.
systemctl enable sddm
Set the default target opf systemd from multi-user.target to graphical.target
so sddm can start without errors.
systemctl set-default graphical.target