-Xbootclasspath:<directories and zip/jar files separated by ;>
                      set search path for bootstrap classes and resources
    -Xbootclasspath/a:<directories and zip/jar files separated by ;>
                      append to end of bootstrap class path
    -Xbootclasspath/p:<directories and zip/jar files separated by ;>
                      prepend in front of bootstrap class path
    -Xnoclassgc       disable class garbage collection
    -Xms<size>        set initial Java heap size
    -Xmx<size>        set maximum Java heap size
    -Xrs              reduce the use of OS signals
    -Xcheck:jni       perform additional checks for JNI functions
    -Xcheck:nabounds  perform additional checks for JNI array operations
    -Xrunhprof[:help]|[:<option>=<value>, ...]
                      perform heap, cpu, or monitor profiling
    -Xdebug           enable remote debugging
    -Xfuture          enable strictest checks, anticipating future default

The -X options are non-standard and subject to change without notice.