This option is useful to load things like EtherBoot.
ETEXI
-HXCOMM Silently ignored for compatibility
-DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
-
DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
"-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
" set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",