Environment

This section describes the environment variables used by Verilator and associated programs.

LD_LIBRARY_PATH

A generic Linux/OS variable specifying what directories have shared object (.so) files. This path should include SystemC and any other shared objects needed at simulation runtime.

MAKE

Names the executable of the make command invoked when using the --build option. Some operating systems may require “gmake” to this variable to launch GNU make. If this variable is not specified, “make” is used.

OBJCACHE

Optionally specifies a caching or distribution program to place in front of all runs of the C++ compiler. For example, “ccache”. If using distcc or icecc/icecream, they would generally be run under ccache; see the documentation for those programs. If OBJCACHE is not set, and at configure time ccache was present, ccache will be used as a default.

SYSTEMC

Deprecated. Used only if SYSTEMC_INCLUDE or SYSTEMC_LIBDIR is not set. If set, specifies the directory containing the SystemC distribution. If not specified, it will come from a default optionally specified at configure time (before Verilator was compiled).

SYSTEMC_ARCH

Deprecated. Used only if SYSTEMC_LIBDIR is not set. Specifies the architecture name used by the SystemC kit. This is the part after the dash in the “lib-{…}” directory name created by a make in the SystemC distribution. If not set, Verilator will try to intuit the proper setting, or use the default optionally specified at configure time (before Verilator was compiled).

SYSTEMC_CXX_FLAGS

Specifies additional flags that are required to be passed to GCC when building the SystemC model. System 2.3.0 may need this set to “-pthread”.

SYSTEMC_INCLUDE

If set, specifies the directory containing the systemc.h header file. If not specified, it will come from a default optionally specified at configure time (before Verilator was compiled), or computed from SYSTEMC/include.

SYSTEMC_LIBDIR

If set, specifies the directory containing the libsystemc.a library. If not specified, it will come from a default optionally specified at configure time (before Verilator was compiled), or computed from SYSTEMC/lib-SYSTEMC_ARCH.

VERILATOR_BIN

If set, specifies an alternative name of the verilator binary. May be used for debugging and selecting between multiple operating system builds.

VERILATOR_COVERAGE_BIN

If set, specifies an alternative name of the verilator_coverage binary. May be used for debugging and selecting between multiple operating system builds.

VERILATOR_GDB

If set, the command to run when using the --gdb option, such as “ddd”. If not specified, it will use “gdb”.

VERILATOR_ROOT

Specifies the directory containing the distribution kit. This is used to find the executable, Perl library, and include files. If not specified, it will come from a default optionally specified at configure time (before Verilator was compiled). It should not be specified if using a pre-compiled Verilator package as the hard-coded value should be correct. See Installation.