ripopov / 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 ...

gdb_systemc_trace's Issues

GDB MemoryError : Cannot access memory at address ...

Hi,
I just tried to use this tool, I am on ubuntu, using SystemC 2.3.3, GNU GDB 9.2, but I get the following error:

** ALERT ** ID: initialize Architectural Registers
** ALERT ** BIOS: initialize BIOS
** ALERT ** DCU: initialize Data Cache

Breakpoint 2, sc_core::sc_simcontext::prepare_to_simulate (this=0x555555618510)
    at /media/skander/data/systemc-2.3.3/src/sysc/kernel/sc_simcontext.cpp:678
678 {
Traceback (most recent call last):
  File "/media/skander/data/gdb_systemc_trace/gdb_scripts/run_trace.py", line 58, in <module>
    design = sc_design.SCModule(simctx)
  File "/media/skander/data/gdb_systemc_trace/gdb_scripts/sc_design.py", line 59, in __init__
    self.__init_from_simctx()
  File "/media/skander/data/gdb_systemc_trace/gdb_scripts/sc_design.py", line 66, in __init_from_simctx
    m_child_objects = stdlib_hacks.StdVectorView(self.value['m_child_objects'])
  File "/media/skander/data/gdb_systemc_trace/gdb_scripts/stdlib_hacks.py", line 42, in __init__
    self.size = self.end - self.begin
**gdb.MemoryError: Cannot access memory at address 0x98**

Do you have any ideas?
Thanks in advance

What would be needed to get fixed point datatypes working?

Does not run!

Hi,

When I followed the process you mentioned in README, I ended up with below eeor? Any clue why?

Here is the error:

simctx = gdb.lookup_symbol("sc_core::sc_curr_simcontext")[0].value().dereference()
AttributeError: 'gdb.Symbol' object has no attribute 'value'

Thank you!

VCD Dump signals/port with different names

Hi @ripopov,
tks for the excellent scripting, I have just a small question, can you point me why the signals/ports name are name port_X some rather than the name written in the sysc?
ps.: I'm compiling with -g -Og