support booting with more than 255 CPUs

SDM[*1] says that if there are CPUs with APIC ID
greater than 254, BIOS is to pass control to OS
in x2APIC mode. Use the fact that QEMU passes in
"etc/max-cpus" max possible "APIC ID + 1" to
detect need for x2APIC mode. Also instead of
CMOS_BIOS_SMP_COUNT which is limited to 256 CPUs
use a new rom file "etc/boot-cpus" that QEMU
supporting more than 256 CPUs will provide.

*1) SDM: Volume 3: EXTENDED XAPIC (X2APIC):
     Initialization by System Software

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
2 files changed
tree: f92bb03aeb1920e616eea43a397ade1c7fc9a4a7
  1. .gitignore
  2. COPYING
  3. COPYING.LESSER
  4. Makefile
  5. README
  6. docs/
  7. scripts/
  8. src/
  9. vgasrc/