This is the second blog entry in the Acceleration Platform series. Previously, we discussed how to create the hardware and how to pass the metadata to Vitis™ via the XSA.
In this entry we will discuss how to use this XSA and create the software images needed to accelerate your design on your target platform.
You can find the other entries at the links below:
Part One: Creating the hardware project for the Acceleration Platform in Vivado
Part Three: Packaging the Accelerated Platform in Vitis
Part Four: Testing the Custom Acceleration Platform in Vitis
Introduction:
Users familiar with OpenCL might be aware of the term "kernel", where a function executing in OpenCL is called a "kernel".
The same nomenclature is used in the Vitis acceleration flows. However, the Xilinx Runtime (XRT) API is used to execute the kernels.
The XRT is Linux based, and will run on the x86, or on the development boards (aarch64 or arm). The XRT is functionality independent from the architecture it is executing on, meaning it does not know if it is executing on an x86 or a development board (aarch64, or arm).
However, for the edge (aarch64, or arm) platforms we need to add the ZOCL driver. The ZOCL driver is used to allocate resources for each kernel. In this blog we will discuss how to add the XRT and ZOCL to a new or existing PetaLinux project.
Adding the XRT to the PetaLinux Project:
petalinux-create -t project --template zynqMP -n zcu104_base_sw cd zcu104_base_sw petalinux-config --get-hw-description=<path to XSA>
Select DTG Settings -> (zcu104-revc) MACHINE_NAME
Open the project-spec/meta-user/conf/user-rootfsconfig, and add the following:
CONFIG_xrt CONFIG_xrt-dev CONFIG_zocl CONFIG_opencl-clhpp-dev CONFIG_opencl-headers-dev CONFIG_packagegroup-petalinux-opencv
petalinux-config -c rootfs
User Packages, and select all here
Now add the zocl driver node to the system-user.dtsi.
/include/ "system-conf.dtsi"
/{
};
&axi_intc_0 {
xlnx,kind-of-intr = <0x0>;
xlnx,num-intr-inputs = <0x20>;
};
&amba {
zyxclmm_drm {
compatible = "xlnx,zocl";
status = "okay";
interrupt-parent = <&axi_intc_0>;
interrupts = <0 4>, <1 4>, <2 4>, <3 4>,
<4 4>, <5 4>, <6 4>, <7 4>,
<8 4>, <9 4>, <10 4>, <11 4>,
<12 4>, <13 4>, <14 4>, <15 4>,
<16 4>, <17 4>, <18 4>, <19 4>,
<20 4>, <21 4>, <22 4>, <23 4>,
<24 4>, <25 4>, <26 4>, <27 4>,
<28 4>, <29 4>, <30 4>, <31 4>;
};
};
Then run the following commands:
petalinux-build cd images/linux petalinux-build --sdk petalinux-package --sysroot
Sanity Check:
Before we package our platform it is worth doing a sanity check to make sure that the XRT is added to the rootfs, and that the ZOCL has also been added.
We can do this by booting the Linux image on our board:
cd images/linux petalinux-package --boot --fpga --u-boot
Place the following files onto the boot device, and then boot
- image.ub
- BOOT.BIN
- boot.scr
Verify the XRT library:
Do a grep on the XRT lib in the /usr/lib directory:
ls /usr/lib | grep libxrt_core
Repeat for libxilinxopencl:
ls /usr/lib | grep libxilinxopencl
Verify the ZOCL DT node:
List all of the nodes under amba
ls /sys/devices/platform/amba
And that's it.
We now have a Linux image with XRT support enabled for our development board. We have also generated the sysroot that is needed in Vitis for cross compilation.
If you plan on a series of custom platforms for the same architecture, then you only need to create the one sysroot per version (for example, 2020.1).
For the next steps, see part three of this series: Packaging the Accelerated Platform in Vitis