Helper scripts for QEmu emulation for the Rasperry Pi family of virtual boards

This is a collection of a number of helper-scripts for emulating Raspberry Pi boards within QEmu.

Note: to run these scripts, you need a Linux host. I have no idea if they work with the Linux-emulation on Win10 or within an Apple iShell. Feedback and comments on this issue are welcome.

The scripts were developed and tested with QEmu 5.2-rc2.

Typical Usage

# with original image
sudo extract_kernel.sh 2020-08-20-raspios-buster-armhf-lite.img

# resize image (SD card size has to be a power of 2 for QEmu)
qemu-img resize 2020-08-20-raspios-buster-armhf-lite.img 4G

# first boot: resizes second partition and changes /boot/cmdline.txt
raspi2.sh 2020-08-20-raspios-buster-armhf-lite.img

# extract cmdline.txt again (needed once after first boot)
sudo extract_kernel.sh 2020-08-20-raspios-buster-armhf-lite.img

# create qcow2 image for deltas (optional, but recommended)
qemu-img create -f qcow2 -b 2020-08-20-raspios-buster-armhf-lite.img delta.qcow2

# use delta image in future boots
raspi2.sh delta.qcow2

extract_kernel.sh

This script extracts the commandline, kernels and dtbs for the raspi0, raspi2 and raspi3 virtual boards. This script has to be run as root.

This is necessary because QEmu needs these files outside of the image.

Since the first boot changes the file cmdline.txt within the image, the extraction has to take place two times, once before the first boot and once after the first boot.

raspi_.sh

This is the generic start-script for all raspi-boards. Used by the other scripts, but can also be called directly.

raspi0.sh, raspi2.sh, raspi3.sh

This starts the emulator with the hardware configured for the respective board. The script requires an image as the first parameter. You can add additional QEmu-options starting from the second option, e.g.

raspi2.sh 2020-08-20-delta.qcow2 -snapshot

will start the emulator in snapshot mode (i.e. all changes during the session are discarded afterwards).

Random Notes

To add an USB-disk (stick), do the following:

qemu-img create -f qcow2 virt_disk.qcow2 16G
raspi2.sh delta.qcow2 \
        -drive file=virt_disk.qcow2,if=none,node-name=my_disk \
        -device usb-storage,drive=my_disk

This will show up as /dev/sda in the guest. Don't expect great performance, USB-storage seems to use the USB 1.1 interface.

The Pi-Zero kernel currently boots directly into a kernel panic.

After successful shutdown, all kernels end with a kernel panic, which can be safely ignored.