Extras

The EXTRAS SCons option is a way to add functionality in M5 without adding your files to the M5 source tree. It's present to allow a user to compile in additional functionality that isn't or can't be distributed with M5. This is useful for code that has an incompatible license, or code that is not suitable for inclusion in the M5 source tree at the present time.

The EXTRAS functionality is used to support EIO traces. The trace reader for EIO is licensed under the SimpleScalar license and the code to read these traces is not included in the M5 distribution.

The next examples show how to compile the EIO code, however if the extras path is modified any other suitable extra could be compiled in. To compile in code using EXTRAS simply execute the following

scons EXTRAS=/path/to/m5_2.0_encumbered/eio build/ALPHA_SE/m5.opt

Inside the directory is a SConscript that SCons uses to compile the appropriate sources and add any SimObjects of iterest.

To run a regression with EXTRAS use a command line similar to the following:

./util/regress --scons-opts="EXTRAS=/tmp/m5_2.0b4_encumbered -j2" quick