qemu: check rtc presence before reading cpu count from cmos

Read month register which should never have a value larger than 12.
In case the read returns 0xff assume the rtc isn't there.
Don't try to read the cpu count from cmos without rtc.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
1 file changed
tree: 60b23738f6b4679576a5416f55f4dd81365f791a
  1. .gitignore
  2. COPYING
  3. COPYING.LESSER
  4. Makefile
  5. README
  6. docs/
  7. scripts/
  8. src/
  9. vgasrc/