Files
gem5/util/systemc/gem5_within_systemc
Gabe Black 7121bc58ac util,systemc: Update the stats API used in one of the examples.
A new parameter as added to the initText method in March of this year,
but this example code was not updated which prevents it from compiling.

This change adds the parameter to the call and sets it to what the
documenting comments say is the default, true.

Change-Id: Ic8da46dba03f01f338c38a7bc02ba232a90ae349
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32641
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2020-08-16 04:29:34 +00:00
..

This directory contains a demo of C++ configuration of gem5.  The intention
is to provide a mechanism to allow pre-generated config.ini files generated
by Python-based gem5 to be reloaded in library-base versions of gem5
embedded in other systems using C++ calls for simulation control.

This directory contain a demo of hosting a C++ configured version of gem5
onto SystemC's event loop.  The hosting is achieved by replacing 'simulate'
with a SystemC object which implements an event loop using SystemC scheduler
mechanisms.

The sc_... files here should probably be hosted in a diferent directory and
buildable as a library.

Files:

    main.cc                 -- demonstration top level
    sc_logger.{cc,hh}       -- rehosting of DPRINTF onto SC_REPORT
    sc_module.{cc,hh}       -- SystemC simulation loop base class
    sc_gem5_control.{cc,hh} -- Alternative extra wrapping to allow gem5
                                Systems to be instantiated as single
                                sc_module objects.
    stats.{cc,hh}           -- Stats dumping (copied from util/cxx_config)

Read main.cc for more details of the implementation and sc_... files for

To build:

First build gem5 as a library with cxx-config support and (optionally)
without python.  When building the library, disable gem5's native SystemC
API support, as that will conflict with the external version.  Also build a
normal gem5 (cxx-config not needed, Python needed):

> cd ../../..
> scons build/ARM/gem5.opt
> scons --with-cxx-config --without-python USE_SYSTEMC=0 \
>       build/ARM/libgem5_opt.so
> cd util/systemc

Note: For MAC / OSX this command should be used:
> scons --with-cxx-config --without-python USE_SYSTEMC=0 \
>       build/ARM/libgem5_opt.dylib

Set a proper LD_LIBRARY_PATH e.g. for bash:
> export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/path/to/gem5/build/ARM/"

or for MAC / OSX:
> export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/path/to/gem5/build/ARM/"


Then edit the Makefile to set the paths for SystemC, e.g:

    Linux:
    SYSTEMC_INC = /opt/systemc/include
    SYSTEMC_LIB = /opt/systemc/lib-linux64

    MAC / OSX:
    SYSTEMC_INC = /opt/systemc/include
    SYSTEMC_LIB = /opt/systemc/lib-macosx64

Then run make:

> make

Make a config file for the C++-configured gem5 using normal gem5

> ../../../build/ARM/gem5.opt ../../../configs/example/se.py -c \
>       ../../../tests/test-progs/hello/bin/arm/linux/hello

The binary 'gem5.opt.cxx' can now be used to load in the generated config
file from the previous normal gem5 run.

Try:

> ./gem5.opt.cxx m5out/config.ini

This should print:

> Hello world!

The .ini file can also be read by the Python .ini file reader example:

> ../../../build/ARM/gem5.opt ../../../configs/example/read_ini.py \
>       m5out/config.ini

If you are interested in SystemC Transaction Level Modeling (TLM2) please have
a look into /util/tlm.