qemu-rpi-kernel

The build-kernel-qemu script is designed for Debian-based distributions. To build the kernel on Windows or macOS, you must manually replicate the logic found in the build-kernel-qemu script.

Ensure you have the following installed and available:

• An ARM toolchain (e.g., gcc-arm-linux-gnueabihf equivalents for your OS).
• All other dependencies required by the kernel build process.

Refer to the build-kernel-qemu script line-by-line to guide your manual build process on these platforms.

Before attempting native emulation of Rpi2/3 using QEMU's raspi2/raspi3 machine, ensure you have the following:

• Qemu 5.1+
• Raspberry pi img file
• Raspberry pi kernel image
• Relevant dtb files

If you are using libvirt (version 5.0.0 or later), you can use virt-install to create a guest named pi. This allows you to manage the emulation using standard tools like virsh and virt-manager. The kernel and DTB are passed via the --boot flag.

$ virt-install \
  --name pi \
  --arch armv6l \
  --machine versatilepb \
  --cpu arm1176 \
  --vcpus 1 \
  --memory 256 \
  --import \
  --disk /.../2019-09-26-raspbian-buster-lite.img,format=raw,bus=virtio \
  --network user,model=virtio \
  --video vga \
  --graphics spice \
  --rng device=/dev/urandom,model=virtio \
  --boot 'dtb=/.../versatile-pb-buster.dtb,kernel=/.../kernel-qemu-4.19.50-buster,kernel_args=root=/dev/vda2 panic=1' \
  --events on_reboot=destroy

To automate the kernel building process on a Debian-based distribution, use the build-kernel-qemu script. Follow these steps:

1. Clone this repository and navigate to the directory.
2. Prepare configuration files: Create build-kernel-qemu.conf, config_file, and linux-arm.patch for your target kernel version (you can copy existing versioned files as templates).
3. Install required dependencies: sudo apt install build-essential gcc-arm-linux-gnueabihf bison flex libncurses-dev
4. Execute the build script: ./build-kernel-qemu
5. Configure the kernel: Use the menu configuration interface to make desired choices or save the defaults.

Note on USB Webcams: If you enable USB webcam modules in the build script, ensure you select the correct drivers in menuconfig. Be aware that while USB generally works in QEMU, USB webcams may encounter issues.

To emulate a Raspberry Pi using QEMU's native raspi2 or raspi3 machines, you must first extract the kernel image and relevant Device Tree Blob (DTB) files from your Raspberry Pi .img file.

Follow these steps:

1. Mount the image file: Use losetup to create a loop device and mount the first partition.
2. Copy files: Copy all files matching kernel* and *.dtb from the mounted partition to your current working directory.
3. Cleanup: Unmount the partition and detach the loop device.

# Mount the image file
sudo mkdir /mnt/rpi
sudo losetup -f --show -P <path-to-rpi-image-file>
sudo mount /dev/loop<no>p01 /mnt/rpi

# Copy kernel files / dtb files
cp /mnt/rpi/kernel* .
cp /mnt/rpi/*.dtb .

# Unmount the image file
sudo umount /mnt/rpi
sudo losetup -d /dev/loop<no>

For kernel version 5.4.51, use a specific QEMU command configuration that utilizes virtio-blk-pci and updated kernel arguments. Ensure the root parameter in -append points to /dev/vda2.

$ qemu-system-arm \
  -M versatilepb \
  -cpu arm1176 \
  -m 256 \
  -drive "file=/.../2020-05-27-raspios-buster-lite-armhf.img,if=none,index=0,media=disk,format=raw,id=disk0" \
  -device "virtio-blk-pci,drive=disk0,disable-modern=on,disable-legacy=off" \
  -net "user,hostfwd=tcp::5022-:22" \
  -dtb /.../versatile-pb-buster-5.4.51.dtb \
  -kernel /.../kernel-qemu-5.4.51-buster \
  -append 'root=/dev/vda2 panic=1' \
  -no-reboot

Run the following command to start emulation of a Raspberry Pi 3B+ using the qemu-system-aarch64 emulator.

Note: Ensure you have already extracted the kernel8.img and the appropriate .dtb file from your image, and that the -sd argument points to your actual Raspberry Pi image file.

sudo qemu-system-aarch64 -M raspi3b -append "rw earlyprintk loglevel=8 console=ttyAMA0,115200 dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2 rootdelay=1" -dtb ./dtbs/bcm2710-rpi-3-b-plus.dtb -sd 2020-08-20-raspios-buster-armhf-full.img -kernel kernel8.img -m 1G -smp 4 -serial stdio -usb -device usb-mouse -device usb-kbd

You can use the lukechilds/dockerpi Docker image to automate the process of running a Raspberry Pi emulation.

docker run -it lukechilds/dockerpi