Network booting RetroPie on Raspberry Pi 4

retropie-network-boot-pi4.md

Diskless RetroPie on Raspberry Pi 4

This should work fine when booting to in ARMv7 mode (32bit) - currently only version of RetroPie.

AArch64 mode (64bit) uses U-Boot and I couldn't set it up yet...

1. Install Raspbian to an SD Card and boot your Raspberry Pi 4

    TODO
   

2. Find your Raspberry Pi 4 serial number, will be referred to as $SERIAL later

    TODO
   

3. Enable Network Booting for Raspberry Pi

    TODO
   

4. Setup NFS shares for boot and root partitions on the NFS server

    192.168.0.10:/tftpboot/$SERIAL/     # /boot
    192.168.0.10:/pi4-$SERIAL/          # /
   

With network booting enabled Raspberry Pi tries to load files from /tftpboot/$SERIAL/ by default. It's configurable with DHCP options but lets stick to defaults here.

1. Setup TFTP server (eg dnsmasq, dhcpd, opentftpd, etc) on NFS server for /tftpboot

2. Setup your DHCP server to provide DHCP options for you Raspberry Pi 4

    # vendor-specific
    option-43='Raspberry Pi Boot   '  # trailing spaces, very important
   
    # vendor-class
    option-60='PXEClient'
   
    # tftp-server-name
    option-66='192.168.0.10'         # NFS/TFTP server
    # in case your DHCP server and TFTP server are on different hosts
   

3. Setup directories

    mkdir -p ~/raspberry/{iso,nfs}root/boot
   

4. Download latest Retropie image

    cd ~/raspberry/
    curl -sSLO https://github.com/RetroPie/RetroPie-Setup/releases/download/4.8/retropie-buster-4.8-rpi4_400.img.gz
   

5. Create loopback devices from partitions in the image, mount filesystems

    sudo kpartx -v -a ~/raspberry/retropie-buster-4.8-rpi4_400.img
    sudo mount /dev/mapper/loop0p2 ~/raspberry/isoroot
    sudo mount /dev/mapper/loop0p1 ~/raspberry/isoroot/boot
   

6. Mount NFS shares

    cd ~/raspberry
    sudo mount -t nfs 192.168.0.10:/pi4-$SERIAL/ ./nfsroot/
    sudo mkdir -p nfsroot/boot
    sudo mount -t nfs 192.168.0.10:/tftpboot/$SERIAL/ ./nfsroot/boot/
   

7. Copy files from ISO into NFS

    cd ~/raspberry
    sudo rsync -azv ./isoroot/ ./nfsroot/
   

8. Update /boot/cmdline.txt. Important bits are root=/dev/nfs, nfsroot=... and ip=dhcp. I've disabled reduced logging for debugging boot issues, you can keep loglevel and quiet if you'd like.

    cd ~/raspberry
    sudo -e ./nfsroot/boot/cmdline.txt
    #contents
    console=serial0,115200 console=tty1 root=/dev/nfs nfsroot=192.168.0.10:/pi4-$SERIAL ip=dhcp rw rootwait consoleblank=0 plymouth.enable=0
   

9. Update /etc/fstab

    cd ~/raspberry
    sudo -e ./nfsroot/etc/fstab
    #contents
    proc /proc proc defaults 0 0
    192.168.0.10:/pi4-$SERIAL / nfs defaults 0 0
    192.168.0.10:/tftpboot/$SERIAL /boot nfs defaults 0 0
   

10. Enable SSH

     sudo ln -s /lib/systemd/system/ssh.service ./nfsroot/etc/systemd/system/sshd.service
     sudo ln -s /lib/systemd/system/ssh.service ./nfsroot/etc/systemd/system/multi-user.target.wants/ssh.service
    

11. Remove SD card from Raspberry Pi and attempt to network boot now.

12. You can SSH into your Raspberry Pi to finish configuring RetroPie