• Raspberry Pi Zero (2) (W)
• Waveshare 1.3inch OLED HAT
• Tested on Rasberry Pi OS Buster, Bullseye and DietPi Bullseye

• gadget_cdrom converts your Raspberry Pi to virtual usb cdrom.
• https://video.ploud.fr/videos/watch/6d0b1014-bb39-4714-a984-15a24a9ac58e
• https://www.youtube.com/watch?v=DntezzK9Eqc

• You can switch between HDD mode, virtual cdrom mode, and virtual flash drive mode.
• HDD mode - in that mode your Raspberry Pi is basically USB flash drive connected to your computer.
• CD mode - in that mode you select some iso you uploaded to Raspberry Pi in HDD mode, and the rpi will pretend to be that cdrom.
• USB mode - the rpi will pretend to be a flash drive, presenting the usb .img you selected.

• Key1 - Activate selected image
• Key2 - Deactivate image
• Key3 - Change mode
• Joystick Down - next image
• Joystick Up - previous image
• Joystick Left - shutdown / power on

There are customized DietPi images with gadget_cdrom and kernel patch for big isos in the releases section, just write it to sd-card (you can use rpi-imager, dd, etc.), turn rpi on and wait a few minutes to get everything ready.

https://github.com/rzrbld/gadget_cdrom_bpi_m2_zero

sudo apt install -y p7zip-full python3-rpi.gpio python3-smbus python3-spidev \
                    python3-numpy python3-pil fonts-dejavu ntfs-3g

# sudo ./create_image.sh
Space available: 24G
Size, e.g. 16G? 8G"
Creating 8G image...
Done!

• Add dtoverlay=dwc2 to /boot/config.txt
• Add dwc2 to /etc/modules
• Enable SPI

sudo raspi-config
Interfacing Options
SPI
Yes

• Clone gadget_cdrom

cd /opt
sudo git clone https://github.com/tjmnmk/gadget_cdrom.git

• Enable systemd service:

sudo ln -s /opt/gadget_cdrom/gadget_cdrom.service /etc/systemd/system/gadget_cdrom.service
sudo systemctl enable gadget_cdrom.service

• reboot rpi

sudo reboot

• Apply this patch
• Build kernel: https://www.raspberrypi.org/documentation/linux/kernel/building.md