Writing a Custom Makefile - 2022.1 English

Vitis Unified Software Platform Documentation: Application Acceleration Development (UG1393)

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2022.1 English

Your custom Makefile should provide similar functions as the template Makefile. The basic steps to compile in VSC are similar to other Vitis tool flows, as shown below:

v++ --compile my_acc.cpp -o my_acc.o
v++ --link my_acc.o -o hw.xclbin # also outputs hw.o
g++ -c main.cpp -o main.o
g++ -l host.exe main.o my_acc.o hw.o -lvpp_acc -lxrt_core -lpthread
Some things to notice in these commands:
  1. The v++ compile command does not use the -k option to specify a kernel name. This is because the source code defines a class derived from the VPP_ACC class that enables the Vitis tools to compile the VSC system.
  2. The v++ --compile compile command produces .o files instead of .xo files. These files are used by Vitis compiler and g++ to build the hardware and host systems.
  3. The v++ --link command will use the .o files as inputs and generate both an .xclbin for the hardware accelerator, and a hw.o which contains compiled objects for the VSC hardware-software interfaces required by the host application and used by g++.
  4. The commands will also need to have specific options for the respective tools and modes, for example --platform and --target.

Alternatively, you can create a shared (dynamically loadable) library to let the accelerator be easily integrated into a third-party application. For example, libmy_acc.so as given below:

v++ -c my_acc.cpp -o my_acc.o
v++ -l my_acc.o kernel.xo -o hw.xclbin # also produces hw.o
g++ -c -fPIC app.cpp -o app.o 
## Command to create the shared library:
g++ -shared -fPIC -o libmy_acc.so app.o my_acc.o \
    -Wl,--whole-archive ${XILINX_VITIS}/system_compiler/lib/x86/libvpp_acc.a \
## The link command using the shared library
g++ -l host.exe main.o -lmy_acc -lxrt_hw -lpthread