Before starting the kernel development process, the developer should have familiarity with high-level synthesis (HLS) concepts. The HLS compiler turns C/C++ code into RTL designs which then map onto the device fabric.
The HLS compiler is more restrictive than standard software compilers. For example, there are unsupported constructs including: system function calls, dynamic memory allocation and recursive functions. For more information, see the Vitis High-Level Synthesis User Guide (UG1399).
More importantly, always keep in mind that the structure of the C/C++ source code has a strong impact on the performance of the generated hardware implementation. This methodology guide will help you structure the code to meet the application throughput goals. For specific information on programming kernels, see Developing PL Kernels using C++.