The parameters is used to specify Simics capabilities.
With the option -log you can specify the agent to log TCF traces in the file specified with option log-file. Option log-file defaults to 'tcf.log'. The flag -log is automatically set if log-file is specified. If "-" is set as log file, logs will be sent to stderr.
With the option log-mode you can specify what TCF traces will be logged. The command is a comma separated list of modes. The list of modes is available through auto-completion. By default, all modes are selected.