GDB Kernel-Based Debugging - 2020.2 English

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

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2020.2 English

GDB kernel debugging is supported for the software emulation and hardware emulation flows. When the GDB executable is connected to the kernel in the IDE or command line flows, you can set breakpoints and query the content of variables in the kernel, similar to normal host code debugging. This is fully supported in the software emulation flow because the kernel GDB processes attach to the spawned software processes.

However, during hardware emulation, the kernel source code is transformed into RTL, created by Vitis HLS, and executed. As the RTL model is simulated, all transformations for performance optimization and concurrent hardware execution are applied. For that reason, not all C/C++/OpenCL lines can be uniquely mapped to the RTL code, and only limited breakpoints are supported and at only specific variables can be queried. Today, the GDB tool therefore breaks on the next possible line based on requested breakpoint statements and clearly states if variables can not be queried based on the RTL transformations.