Compiling and Linking for Arm - 2021.1 English

Vitis Unified Software Platform Documentation: Application Acceleration Development (UG1393)
Document ID
UG1393
Release Date
2022-03-29
Version
2021.1 English
Tip: Set up the command shell or window as described in Setting Up the Vitis Environment prior to running the tools.

The host program (host.exe), is cross-compiled for an Arm processor, and linked using the following two step process:

  1. Compile the host.cpp into an object file (.o) using the GNU Arm cross-compiler version of g++:
    Note: aarch64 is used for Zynq® UltraScale+™ (A53) and Versal™ (A72) devices. aarch32 is used for Zynq-7000 SoC (A9) and the tool chain is in a different location. 
    $XILINX_VITIS/gnu/aarch64/lin/aarch64-linux/bin/aarch64-linux-gnu-g++ \
-D__USE_XOPEN2K8 -I$SYSROOT/usr/include/xrt -I$XILINX_VIVADO/include \
-I$SYSROOT/usr/include -c -fmessage-length=0 -std=c++14 \
--sysroot=$SYSROOT -o src/host.o ../src/host.cpp
  2. Link the object file with required libraries to build the executable application. 
    $XILINX_VITIS/gnu/aarch64/lin/aarch64-linux/bin/aarch64-linux-gnu-g++ \
-o host.exe src/host.o -lxilinxopencl -lpthread -lrt -lstdc++ -lgmp -lxrt_core \
-L$SYSROOT/usr/lib/ --sysroot=$SYSROOT

When compiling the application for use with an embedded process, you must specify the sysroot for the application. The sysroot is part of the platform where the basic system root file structure is defined, and is installed as described in Installing Embedded Platforms .

Important: The above examples rely on the use of $SYSROOT environment variable that must be used to specify the location of the sysroot for your embedded platform.

The following are key elements to compiling the host code for an edge platform:

Compilation
  • The cross compiler needed is the aarch64-linux-gnu-g++ found in the Vitis installation hierarchy.
  • The required include paths are:
    • $SYSROOT/usr/include
    • $SYSROOT/usr/include/xrt
    • $XILINX_VIVADO/include
Linking
  • $SYSROOT/usr/lib: Library paths location.
  • xilinxopencl: XRT required library.
  • pthread: XRT required library.
  • rt: XRT required library.
  • stdc++: XRT required library.
  • gmp: XRT required library.
  • xrt_core: XRT required library.

Building XRT Native API

XRT provides a native XRT API for C, C++, and Python, as described on the XRT site at https://xilinx.github.io/XRT/2020.2/html/xrt_native_apis.html. To use the native XRT API, the host application must link with the xrt_coreutil library instead of the xlinxopencl library. The command line uses a few different settings as shown in the following example for compilation and linking:

$XILINX_VITIS/gnu/aarch64/lin/aarch64-linux/bin/aarch64-linux-gnu-g++ -c \
-D__USE_XOPEN2K8 -I$SYSROOT/usr/include/xrt -I$XILINX_VIVADO/include \
-I$SYSROOT/usr/include -fmessage-length=0 -std=c++14 --sysroot=$SYSROOT \
-o src/host.o ../src/host.cpp
$XILINX_VITIS/gnu/aarch64/lin/aarch64-linux/bin/aarch64-linux-gnu-g++ -l \
-lxrt_coreutil -lpthread -lrt -lstdc++ -lgmp -lxrt_core -L$SYSROOT/usr/lib/ \
--sysroot=$SYSROOT -o host.exe src/host.o