QEMU emulation of Raspberry Pi 3b

raspiqemu.md

1. Install QEMU.
2. Since the recent Raspberry Pi OS has removed the preset user, use a legacy version like 2022-01-28 will work. Download the Raspberry Pi OS and extract these files from the image:

• bcm2710-rpi-3-b.dtb
• kernel8.img

3. Resize the image to 8G to avoid the disk error. Since the disk space has to be the square of 2 and the image itself occupies 3.8G already. If you want to make more actions, please allocate a larger space.

qemu-img resize 2022-01-28-raspios-bullseye-arm64.img 8G

4. Write the following code to a bash file launch.sh, reference to this repo and this spec.

qemu-system-aarch64 \
    -M raspi3b \
    -cpu cortex-a53 \
    -append "rw earlyprintk loglevel=8 console=ttyAMA0,115200 dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2 rootdelay=1" \
    -dtb bcm2710-rpi-3-b.dtb \
    -sd 2022-01-28-raspios-bullseye-arm64.img \
    -kernel kernel8.img \
    -m 1G -smp 4 \
    -serial stdio \
    -usb -device usb-mouse -device usb-kbd \
       -device usb-net,netdev=net0 \
       -netdev user,id=net0,hostfwd=tcp::2222-:22,hostfwd=tcp::9090-:9090 \

and add the permission to run the script by

chmod +x launch.sh

You can now run the OS by

./launch.sh

5. The default user for logging in:

pi
raspberry

6. Open SSH connection on the raspberry pi, use the command

sudo raspi-config

And then go to [Interface Options]->[SSH]->[Yes]->[Finish], reboot the system. And on the host side, use the command to connect to the raspberry pi by SSH.

ssh -p 2222 pi@localhost

7. Extend the disk. First check the sector number by

$ sudo fdisk -l

Device         Boot  Start     End Sectors  Size Id Type
/dev/mmcblk0p1        8192  532479  524288  256M  c W95 FAT32 (LBA)
/dev/mmcblk0p2      532480 8118271 7585792  3.6G 83 Linux

note down the start section of mmcblk0p2 (here is 532480). Next change the partition by fdisk:

pi@raspberrypi:~$ sudo fdisk /dev/mmcblk0 # mmcblk0 is the device

Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): d  # delete the partition
Partition number (1,2, default 2): 2 # number 2

Partition 2 has been deleted.

Command (m for help): n # new a partition
Partition type
   p   primary (1 primary, 0 extended, 3 free)
   e   extended (container for logical partitions)
Select (default p): p # primary
Partition number (2-4, default 2): 2 # the second
First sector (2048-16777215, default 2048): 532480 # the start section noted before
Last sector, +/-sectors or +/-size{K,M,G,T,P} (532480-16777215, default 16777215): # use default end

Created a new partition 2 of type 'Linux' and of size 7.7 GiB.
Partition #2 contains a ext4 signature.

Do you want to remove the signature? [Y]es/[N]o: N # just extend, no need to remove the signature

Command (m for help): w # execute.

The partition table has been altered.
Syncing disks.

Now reboot the system

sudo reboot

And then take the change into effect.

sudo resize2fs /dev/mmcblk0p2

You can now see the space is extended:

pi@raspberrypi:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       7.6G  3.3G  4.0G  46% /
# ...

8. To avoid the certificate expired error, we need to calibrate the date and time.

sudo date --s="2022-12-07 22:30:00"