gadget_cdrom

Requirements

Banana Pi M2 Zero
Waveshare 1.3inch OLED HAT
Tested on Armbian jammy current (5.15.77)

Description

gadget_cdrom converts your Banana Pi M2 Zero to virtual usb cdrom.
Original tjmnmk Youtube video

Usage

You can switch between HDD mode, virtual cdrom mode, and virtual flash drive mode.

Mode	Description	Button
`CD Mode`	the BPI will pretend to be a cdrom and presenting the `.iso` you selected	`Key3`
`USB Mode`	the BPI will pretend to be a flash drive, presenting the usb `.img` you selected.	`Key3`
`HDD Mode`	in that mode your Banana Pi M2 Zero is basically USB flash drive connected to your computer. You can store any files and upload `.iso` and `.img` files to use in `CD` and `USB` Modes	`Key3`
`Shutdown`	Halt/Shutdown PBI	`Joystick Left`
`Init`	State that you'll see during internal storage initialization process after first boot	`-`

Keys

Key1 - Activate selected image
Key2 - Deactivate image
Key3 - Change mode
Joystick Down - next image (only in CD/USB modes)
Joystick Up - previous image (only in CD/USB modes)
Joystick Left - shutdown

Performance

In HDD Mode with MicroSDXC Kingston CANVAS Select Plus 1st class V10 A1 64GB as main storage, my file transfer speed is around 7-8MB/s for read and write.

BPI Images options

Ready to use Armbian + gadget_cdrom image

There are customized Armbian 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 BPI on and wait a few minutes (5-7) to get everything ready. Latest prebuild images uses exFAT as defaut HDD Mode partition iso.img.

Build your own Armbian image

chekout current armbian-build repo git clone https://github.com/armbian/build.git
chekout current gadget_cdrom_bpi_m2_zero repo git clone -b banana_pi_m2_zero https://github.com/rzrbld/gadget_cdrom_bpi_m2_zero.git
copy userpatches form gadget_cdrom_bpi_m2_zero directory to armbian build folder cp -r /git/gadget_cdrom_bpi_m2_zero/armbian/banapi_m2_zero/userpatches/* /git/build/userpatches/
compile image cd /git/build/ && ./compile.sh BOARD=bananapim2zero BRANCH=current RELEASE=jammy BUILD_MINIMAL=yes BUILD_DESKTOP=no KERNEL_ONLY=no KERNEL_CONFIGURE=no COMPRESS_OUTPUTIMAGE=sha,gpg,gz in case of error with debian repos - add this parameters DEBIAN_MIRROR='%my_favorite_mirror%' NO_APT_CACHER=yes list of Debian mirrors i.e. cd /git/build/ && ./compile.sh BOARD=bananapim2zero BRANCH=current RELEASE=jammy BUILD_MINIMAL=yes BUILD_DESKTOP=no KERNEL_ONLY=no KERNEL_CONFIGURE=no COMPRESS_OUTPUTIMAGE=sha,gpg,gz DEBIAN_MIRROR='ftp.ru.debian.org/debian/' NO_APT_CACHER=yes

Userpatches

 banapi_m2_zero
    └── userpatches
        ├── customize-image.sh #pre install gadget cdrom
        ├── kernel #patch for support isos bigger than ~2.5GB (Optional)
        ├── linux-sunxi-current.config #default linux kernel config (ensure that SPIDEV & Mass Storage is set to <m>/<y>)
        └── README.md #compile parameters

Manual Installation

Install dependencies

apt update -y -q && \
apt install -y -q sed \
                  git \
                  vim p7zip-full \
                  armbian-config \
                  python3-smbus \
                  python3-numpy \
                  python3-pil \
                  fonts-dejavu \
                  ntfs-3g \
                  exfat-fuse \
                  exfatprogs \
                  python3-dev \
                  python3-pip \
                  zip \
                  unzip \
                  dosfstools

Create a file for wiringPi

#make a file for wiringPi
mkdir /var/lib/bananapi/ && touch /var/lib/bananapi/board.sh
echo "BOARD=bpi-m2z" >> /var/lib/bananapi/board.sh
echo "BOARD_AUTO=bpi-m2z" >> /var/lib/bananapi/board.sh

Checkout patched WiringPi2, RPi.GPIO repos and gadget_cdrom (Banana-pi edition)

mkdir -p /opt/BPI-WiringPi2 && git clone https://github.com/bontango/BPI-WiringPi2.git /opt/BPI-WiringPi2/
mkdir -p /opt/RPi.GPIO && git clone https://github.com/GrazerComputerClub/RPi.GPIO.git /opt/RPi.GPIO
mkdir -p /opt/gadget_cdrom && git clone --branch banana_pi_m2_zero https://github.com/rzrbld/gadget_cdrom_bpi_m2_zero.git /opt/gadget_cdrom

Install Python dependencies

#install pip deps
pip3 install wheel && pip3 install spidev

Build patched WiringPi for BPI

cd /opt/BPI-WiringPi2/ && ./build

Build PRi.GPIO for BPI

cd /opt/RPi.GPIO/ && CFLAGS="-fcommon" python3 setup.py install

Enable spi-spidev

echo "overlays=spi-spidev" >> /boot/armbianEnv.txt
echo "param_spidev_spi_bus=0" >> /boot/armbianEnv.txt

Remove conflicted modules

sed -i '/g_serial/d' /etc/modules
sed -i '/g_ether/d' /etc/modules

Prepare storage

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

Reboot

reboot

Check is everything is ok

gpio readall #shows pinout table 
ls -al /dev/spi* #shows spi device

Add cdrom_gadget to systemd and start

ln -s /opt/gadget_cdrom/gadget_cdrom.service /etc/systemd/system/gadget_cdrom.service && \
systemctl enable gadget_cdrom.service
systemctl start gadget_cdrom.service

Optional

Recompile kernel for support isos bigger than ~2.5GB

Apply this patch
Build kernel: Armbian Linux Build Framework

rzrbld / gadget_cdrom_bpi_m2_zero