+ iverilog -o simulation.out -g2005 -s picorv32.v iverilog: no source files. Usage: iverilog [-EiSuvV] [-B base] [-c cmdfile|-f cmdfile] [-g1995|-g2001|-g2005|-g2005-sv|-g2009|-g2012] [-g<feature>] [-D macro[=defn]] [-I includedir] [-L moduledir] [-M [mode=]depfile] [-m module] [-N file] [-o filename] [-p flag=value] [-s topmodule] [-t target] [-T min|typ|max] [-W class] [-y dir] [-Y suf] [-l file] source_file(s) See the man page for details.