PetaLinux

PetaLinux can be built for these reference designs by using the Makefile in the PetaLinux directory of the repository.

Requirements

To build the PetaLinux projects, you will need a physical or virtual machine running one of the supported Linux distributions as well as the Vitis Core Development Kit installed.

Attention

You cannot build the PetaLinux projects in the Windows operating system. Windows users are advised to use a Linux virtual machine to build the PetaLinux projects.

How to build

From a command terminal, clone the Git repository and cd into it.

git clone --recursive https://github.com/fpgadeveloper/zynqmp-hailo-ai.git
cd zynqmp-hailo-ai

Launch PetaLinux by sourcing the settings.sh bash script, eg:
```
source <path-to-installed-petalinux>/settings.sh
```
Launch Vivado by sourcing the settings64.sh bash script, eg:
```
source <vivado-install-dir>/settings64.sh
```
Build the Vivado and PetaLinux project for your specific target platform by running the following commands and replacing <target> with one of the following: zcu104, zcu106, zcu106_hpc0, pynqzu, uzev.
```
cd PetaLinux
make petalinux TARGET=<target>
```

The last command will launch the build process for the corresponding Vivado project if that project has not already been built and it’s hardware exported.

Note that there currently is no PetaLinux project for the Genesys-ZU board, because there is currently no PetaLinux BSP available for that board.

Prepare the SD card

Once the build process is complete, you must prepare the SD card for booting PetaLinux.

The SD card must first be prepared with two partitions: one for the boot files and another for the root file system.
- Plug the SD card into your computer and find it’s device name using the dmesg command. The SD card should be found at the end of the log, and it’s device name should be something like /dev/sdX, where X is a letter such as a,b,c,d, etc. Note that you should replace the X in the following instructions.

Warning

Do not continue these steps until you are certain that you have found the correct device name for the SD card. If you use the wrong device name in the following steps, you risk losing data on one of your hard drives.

Run fdisk by typing the command sudo fdisk /dev/sdX
Make the boot partition: typing n to create a new partition, then type p to make it primary, then use the default partition number and first sector. For the last sector, type +1G to allocate 1GB to this partition.
Make the boot partition bootable by typing a
Make the root partition: typing n to create a new partition, then type p to make it primary, then use the default partition number, first sector and last sector.
Save the partition table by typing w
Format the boot partition (FAT32) by typing sudo mkfs.vfat -F 32 -n boot /dev/sdX1
Format the root partition (ext4) by typing sudo mkfs.ext4 -L root /dev/sdX2

Copy the following files to the boot partition of the SD card: Assuming the boot partition was mounted to /media/user/boot, follow these instructions:

$ cd /media/user/boot/
$ sudo cp /<petalinux-project>/images/linux/BOOT.BIN .
$ sudo cp /<petalinux-project>/images/linux/boot.scr .
$ sudo cp /<petalinux-project>/images/linux/image.ub .

Create the root file system by extracting the rootfs.tar.gz file to the root partition. Assuming the root partition was mounted to /media/user/root, follow these instructions:
```
$ cd /media/user/root/
$ sudo cp /<petalinux-project>/images/linux/rootfs.tar.gz .
$ sudo tar xvf rootfs.tar.gz -C .
$ sync
```
Once the sync command returns, you will be able to eject the SD card from the machine.

Boot from SD card

Plug the SD card into your target board.
Ensure that the target board is configured to boot from SD card:
- ZCU10x: DIP switch SW6 must be set to 1000 (1=ON,2=OFF,3=OFF,4=OFF)
- PYNQ-ZU: Switch labelled “JTAG SD” must be flipped to the right (towards “SD”)
- UltraZed-EV: DIP switch SW2 (on the SoM) is set to 1000 (1=ON,2=OFF,3=OFF,4=OFF)
Connect the M.2 M-key Stack FMC and RPi Camera FMC to the FMC connector of the target board. Connect one or more Raspberry Pi camera module v2 to the RPi Camera FMC. For zcu106 design: Connect the [FPGA Drive FMC Gen4] to the HPC1 connector and the RPi Camera FMC to the HPC0 connector.
Connect the USB-UART to your PC and then open a UART terminal set to 115200 baud and the comport that corresponds to your target board.
Connect and power your hardware.

Test the cameras

Log into PetaLinux using the username root and password root.

Check that the cameras have been enumerated correctly by running the v4l2-ctl --list-devices command. The output should be similar to the following:

zcu104rpicamfmc20221:~$ v4l2-ctl --list-devices
vcap_mipi_0_v_proc output 0 (platform:vcap_mipi_0_v_proc:0):
        /dev/video0

vcap_mipi_1_v_proc output 0 (platform:vcap_mipi_1_v_proc:0):
        /dev/video1

vcap_mipi_2_v_proc output 0 (platform:vcap_mipi_2_v_proc:0):
        /dev/video2

vcap_mipi_3_v_proc output 0 (platform:vcap_mipi_3_v_proc:0):
        /dev/video3

Xilinx Video Composite Device (platform:xilinx-video):
        /dev/media0
        /dev/media1
        /dev/media2
        /dev/media3

Note that there will only be video and media devices for the cameras that you have physically connected, so if you have only connected 2 cameras for example, then you should only see 2 video devices and 2 media devices listed.

Run the camera display script with the command displaycams.sh. The script is located in /usr/bin and it can be used to display the video streams from all connected cameras on the monitor.
Run the Hailo demo script with the command hailodemo.sh. The script is located in /usr/bin and it can be used to run YOLOv5 on all connected cameras and display the video streams with bounding boxes on the monitor.

Known issues and limitations

PYNQ-ZU and Genesys-ZU limits

The ZynqMP devices on the PYNQ-ZU and Genesys-ZU boards are relatively small devices in terms of FPGA resources. Fitting the necessary logic to handle four video streams simultaneously can be a challenge on these boards. For this reason, in our Vivado designs for these boards we have included the video pipes for only two cameras: CAM1 and CAM2. We have also removed the VVAS Multi-scaler kernel from these designs, however the kernel is not required to run the Hailo demo.