I am trying to install 5.1 on my mid 2017 macbook from a flash drive. I get to the welcome screen, but I can't do anything there, as the trackpad and keyboard are not responding. As the macbook has only one usb-c port that is occupied by the flash drive I can't connect any other keyboard or mouse. I did not find a solution for similar questions here, they mostly refer to trackpad issues that occur after installation, but I don't even get to the point of finishing the installation.
There is a relevant AskUbuntu answer that may help you: https://askubuntu.com/a/968740/22318
Suggestion is to perform installation using external keyboard and mouse (a USB hub may help you here) and then install some specific drivers, following instructions here: https://github.com/Dunedan/mbp-2016-linux#keyboard--touchpad
Instructions for your laptop should be these (from https://github.com/roadrunner2/macbook12-spi-driver#dkms-module-debian--co):
DKMS module (Debian & co):
As root, do the following (all MacBook's and MacBook Pro's except MacBook8,1 (2015)):
echo -e "\n# applespi\napplespi\nspi_pxa2xx_platform\nintel_lpss_pci" >> /etc/initramfs-tools/modules apt install dkms git clone https://github.com/roadrunner2/macbook12-spi-driver.git /usr/src/applespi-0.1 dkms install -m applespi -v 0.1