iverilog-vpi(1)

NAME
iverilog-vpi - Compile front end for VPI modules

SYNOPSIS
iverilog-vpi [options] sourcefile...

DESCRIPTION

iverilog-vpi is a tool to simplify the compilation of VPI modules for use with Icarus Verilog. It takes on the command line a list of C or C++ source files, and generates as output a linked VPI module. See the vvp(1) man page for a description of how the linked module is loaded by a simulation. By default the output is named after the first source file. For example, if the first source file is named foo.c, the output becomes foo.vpi.

OPTIONS
iverilog-vpi accepts the following options:

-llibrary
    Include the named library in the link of the VPI module. This allows VPI modules to further reference external libraries.

-Ldirectory
    Add directory to the list of directories that will be searched for library files.

-Idirectory
    Add directory to the list of directories that will be searched for header files.

-Ddefine
    Define a macro named define.

--name=name
    Normally, the output VPI module will be named after the first source file passed to the command. This flag sets the name (without the .vpi suffix) of the output vpi module.

PC-ONLY OPTIONS
When built as a native Windows program (using the MinGW toolchain), by default iverilog-vpi will attempt to locate the MinGW tools needed to compile a VPI module on the system path (as set by the PATH environment variable). As an alternative, the user may specify the location of the MinGW tools via the following option.

-mingw=path
    Tell the program the root of the MinGW compiler tool suite. The vvp runtime is compiled with this compiler, and this is the compiler that iverilog-vpi expects to use to compile your source code. If this option accompanies a list of files, it will apply to the current build only. If this option is provided on its own, iverilog-vpi will save the path in the registry and use that path in preference to the system path for subsequent operations, avoiding the need to specify it on the command line every time.

INFORMATIONAL OPTIONS
iverilog-vpi includes additional flags to let Makefile gurus peek at the configuration of the iverilog installation. This way, Makefiles can be written that handle complex VPI builds natively, and without hard-coding values that depend on the system and installation. If used at all, these options must be used one at a time, and without any other options or directives.

--install-dir
    Print the install directory for VPI modules.

--cflags
    Print the compiler flags (CFLAGS or CXXFLAGS) needed to compile source code destined for a VPI module.

--ldflags
    Print the linker flags (LDFLAGS) needed to link a VPI module.

--ldlibs
    Print the libraries (LDLIBS) needed to link a VPI module.

Example GNU makefile that takes advantage of these flags:

    CFLAGS = -Wall -O $(CFLAGS_$@)
    VPI_CFLAGS := $(shell iverilog-vpi --cflags)
    CFLAGS_messagev.o = $(VPI_CFLAGS)
    CFLAGS_fifo.o = $(VPI_CFLAGS)
    messagev.o fifo.o: transport.h
    messagev.vpi: messagev.o fifo.o
        iverilog-vpi $^

AUTHOR
Steve Williams (steve@icarus.com)

SEE ALSO
iverilog(1), vvp(1), <https://steveicarus.github.io/iverilog/>, <http://mingw-w64.yaxm.org/>,

COPYRIGHT
Copyright ©  2002-2026 Stephen Williams
This document can be freely redistributed according to the terms of the
GNU General Public License version 2.0