You can use the following process to debug the system in software emulation for
accelerator card. This process launches
a new terminal that allows for
gdb commands to be used,
as well as displaying the source files for code stepping.
- Complete the
sw_emubuild process, using the
--debugoptions when building the host and kernels.
- Add the
kernel-dbg=trueoption to the xrt.ini file prior to running the application:
- As described in Running Emulation on Data Center Accelerator Cards, set the XCL_EMULATION_MODE to
setenv XCL_EMULATION_MODE sw_emu
- Launch the host application with the .xclbin file: ./host.exe
Launching the host application also launches
gdbin a separate terminal to let you debug the PL kernels in the .xclbin. In
gdb, you can perform all the typical activities to set up your debug environment, such as breakpoint insertion for PL kernels, and step or continue commands to walk through the code.
- You can set a breakpoint on either function name or line number in
gdbusing this syntax. During execution, when it reaches that breakpoint,
gdbautomatically opens the file with the right line number, as long as it can locate the sources. For example,
break <filename>:<function name> break <filename>:<line_num >
Also, you can set a breakpoint for a kernel using a command such as
b Vadd_A_B. This command pauses .xclbin execution in
gdbat the invocation of the specified kernel, in this example the
Vadd_A_Bkernel. In an .xclbin file with multiple kernels, you can add breakpoints for all or specific kernels.Note: When you set the breakpoint in
gdb, you will see a note that the function is not defined and prompting you to make the breakpoint pending on future load. Enter y to proceed.
- In the
gdbterminal, press r to run the application and step through the code, set variable values, and continue.Tip: To use a Textual User Interface (TUI) in
gdb, use the following keystrokes:
- If the TUI is displayed, the source code for the kernel is displayed, as well as the path to the source code defined in the .xclbin by the software emulation build process.
- Step through the code, or press c to let the code run through to completion. The results of your software emulation are displayed in the original command terminal.
- Press q to quit
- Close the