hjking / gdb_systemc_trace

gdb python scripts for SystemC design introspection and tracing

gdb_systemc_trace

GDB Python scripts for SystemC design introspection and tracing

Automatically creates a trace of all signals and module member variables in design

Limitations

Fixed-point datatypes are not supported yet

Installation

Prerequisites

• GDB 8.2 configured with Python scripting support https://www.gnu.org/software/gdb/download/
• libstdc++ pretty printers initialized with .gdbinit https://sourceware.org/gdb/wiki/STLSupport
• Python : to run top-level gdb_systemc_trace.py script
• SystemC 2.3.3 built as .so library with debuginfo (see below)

Running basic example

1. clone gdb_systemc_trace from git and add to $PATH
2. Download SystemC 2.3.3 https://accellera.org/downloads/standards/systemc
3. Build with debug info:

   $ tar xvf systemc-2.3.3.tar.gz 
   $ cd systemc-2.3.3/
   $ mkdir build_debug
   $ cd build_debug/
   $ cmake ../ -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_STANDARD=14
   $ make -j8
   # build SystemC examples
   $ make check -j8
   # it is important to cd into example directory, sometimes they read some files from workdir
   $ cd examples/sysc/risc_cpu
   $ gdb_systemc_trace.py risc_cpu
   # systemc_trace.vcd file will be created
   

4. Use GTKWave or other VCD viewer to view generated vcd:

 $ gtkwave systemc_trace.vcd 

Running simulation with full trace dump

• ./gdb_systemc_trace.py path/to/your/simulation_executable
• systemc_trace.vcd will be created
• Use vcd_hierarchy_manipulator to create hierarchical VCDs: https://github.com/yTakatsukasa/vcd_hierarchy_manipulator
• Use GtkWave to view vcd waveform : http://gtkwave.sourceforge.net/

Tracing only required signals

• ./gdb_systemc_trace.py -l path/to/your/simulation_executable
• List of all detected signals in design will be printed to console
• Copy required signal names (full hierarchical names) into some file, say signals.txt
• ./gdb_systemc_trace.py -f signals.txt
• systemc_trace.vcd will be created

Print design tree

• ./gdb_systemc_trace.py -p path/to/your/simulation_executable

Passing arguments to simulation executable

• ./gdb_systemc_trace.py path/to/your/simulation_executable argument_1 argument_2 ...