Press F9 on power on to select boot device, then select "Boot From EFI File", select ANACONDA and browse to /EFI/BOOT/xen.efi
This will read the default settings from /EFI/BOOT/xen.cfg, so you will have to modify the file on a second machine which can read the USB stick.*
Add "efi=attr=uc" to the end of the first line in the [qubes] section /EFI/BOOT/xen.cfg like so:
...
[qubes]
options=none efi=attr=uc
...
Follow steps 3-5 in https://www.qubes-os.org/doc/uefi-troubleshooting/#system-crashrestart-when-booting-installer to complete the installation.
---
Audio: working
WiFi: working
Ethernet: working
USB: working
DisposableVM: not working
Suspend to RAM: not working, won't start after suspend
Hibernate: not working (?), screen is turned off, can resume to screensaver login screen
Boot time from power on to login screen: 1m 41s
*)
I installed Debian Netinst on the same machine first, this allowed me to do the following:
sudo mount /dev/sdb2 /mnt/usb
sudo sed -i -e 's/^options=.*/\0 efi=attr=uc/' /mnt/usb/EFI/BOOT/xen.cfg
sudo reboot