tw_osl_vsprintf
tw_osl_vsprintf(event->parameter_data, event_specific_desc, ap);
tw_osl_vsprintf(print_str + tw_osl_strlen(print_str), fmt, ap);
#ifndef tw_osl_vsprintf
extern TW_INT32 tw_osl_vsprintf(TW_INT8 *dest, const TW_INT8 *fmt, va_list ap)