GNet Solutions » Hardware Hacking » Raspberry Pi

This is a guide on virtualizing an ARM based operating system, in this case Raspbian for the Raspberry Pi 3, on an x86_64 Arch Linux system.

Prepare the environment¶

• Make sure the system is up to date:
  

  sudo pacman -Syu
  

• Install a few dependencies:
  

  sudo pacman -S git base-devel wget
  

Prepare Disk Image¶

• Create the guest drive:
  

  dd if=/dev/zero of=~/raspi.img bs=1M count=16384
  

• Format the guest drive:
  

  fdisk ~/raspi.img
  

  • Basic format:
    

    n
    p
    1
    <enter>
    +200M
    n
    p
    <enter>
    <enter>
    <enter>
    w
    

• Download the latest raspberry pi OS image:
  

  mkdir ~/raspios && cd ~/raspios
  wget https://downloads.raspberrypi.org/raspios_lite_armhf/images/raspios_lite_armhf-2022-01-28/2022-01-28-raspios-bullseye-armhf-lite.zip
  unzip 2022-01-28-raspios-bullseye-armhf-lite.zip
  

• Populate the guest drive:
  

  mkdir ~/src_boot && mkdir ~/src_root && mkdir ~/dst_boot && mkdir dst_root
  sudo losetup -f --show ~/raspi.img
  sudo partx -a /dev/loop0
  sudo mkfs.vfat /dev/loop0p1
  sudo mkfs.ext4 /dev/loop0p2
  sudo mount /dev/loop0p1 ~/dst_boot
  sudo mount /dev/loop0p2 ~/dst_root
  sudo losetup -f -o 4194304 --show ~/raspbian/2022-01-28-raspios-bullseye-armhf-lite.img
  sudo mount /dev/loop1 ~/src_boot
  sudo losetup -f -o 272629760 --show ~/raspios/2022-01-28-raspios-bullseye-armhf-lite.img
  sudo mount /dev/loop2 ~/src_root
  sudo cp -r ~/src_boot/*.* ~/dst_boot/
  sudo cp -r ~/src_root/* ~/dst_root/
  

• Edit the guest drive fstab:
  

  sudo nano ~/root/etc/fstab
  

  • And change the following:
    

    /dev/sda1  /boot           vfat    defaults          0       2
    /dev/sda2  /               ext4    defaults,noatime  0       1
    

• Unmount the guest drive:
  

  sudo umount ~/src_boot
  sudo umount ~/src_root
  sudo umount ~/dst_boot
  sudo umount ~/dst_root
  sudo losetup -d /dev/loop2
  sudo losetup -d /dev/loop1
  sudo losetup -d /dev/loop1
  

Install Qemu¶

• Install qemu and the extra architectures:
  

  pacman -S git qemu qemu-arch-extra wget
  

• Download prebuilt kernels:
  

  mkdir ~/git && cd ~/git
  git clone https://github.com/dhruvvyas90/qemu-rpi-kernel.git
  

Run Qemu¶

• Run the newly built kernel with the latest raspbian:
  

  qemu-system-aarch64 -kernel ~/git/qemu-rpi-kernel/kernel-qemu-5.10.63-bullseye -cpu arm1176 -M raspi3b -m 1024 -dtb ~/git/qemu-rpi-kernel/native-emulation/dtbs/bcm2711-rpi-4-b.dtb -serial stdio -append "root=/dev/sda2 rootfstype=ext4 rw" -drive format=raw,file=/media/winshare/raspi.img -net nic,macaddr=20:20:20:67:89:0a -net user,hostfwd=tcp::5022-:22 -no-reboot
  

• Log in as the user pi with the password raspberry

• Configure the pi to your use case:
  

  sudo raspi-config
  

  • Go to Interfacing and enable SSH.
  • Change Localization.

Compiling Latest kernel¶

Install ARM toolchain:¶

• Clone the toolchain repo (using --depth 1 will decrease the overall download size by 400MB):
  

  mkdir ~/git && cd ~/git
  git clone --depth 1 https://github.com/raspberrypi/tools.git
  

• Add the tools to your path:
  

  echo 'export PATH=$PATH:~/git/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin' >> ~/.bash_profile
  

• Source the .bash_profile:
  

  source ~/.bash_profile
  

Compile Kernel¶

• Download the qemu-rpi-kernel repo:
  

  cd ~/git
  git clone https://github.com/dhruvvyas90/qemu-rpi-kernel.git
  

• Clone the specific kernel version to use:
  

  cd qemu-rpi-kernel/tools
  git clone -b rpi-5.10.y --depth 1 https://github.com/raspberrypi/linux.git
  

• Modify the kernel compile script to use Arch commands:
  

  sed -i.bak -e's/sudo\ apt-get\ update/sudo\ pacman\ -Syu/g' -e's/sudo\ apt-get\ install\ git\ libncurses5-dev\ gcc-arm-linux-gnueabihf/sudo\ pacman\ -S\ git/g' build-kernel-qemu
  

• Edit the build-kernel-qemu script:
  

  vi build-kernel-qemu
  

  • And comment out all COMMIT versions except for the desired commit, and also comment out the exit command before the make commands:
    

    #COMMIT=6820d0cbec64cfee481b961833feffec8880111e
    #COMMIT=raspberrypi-kernel_1.20171029-1
    #COMMIT="" 
    COMMIT=rpi-5.10.y
    
    #exit
    

• Run the build script:
  

  ./build-kernel-qemu
  

Resources¶

• https://azeria-labs.com/emulate-raspberry-pi-with-qemu/
• http://graznik.de/posts/emulate-raspberry-pi-with-qemu/
• http://downloads.raspberrypi.org/raspbian/images/raspbian-2018-03-14/
• https://github.com/raspberrypi/linux/releases
• https://github.com/dhruvvyas90/qemu-rpi-kernel