Tell BIOS about the number of CPUs

Previously, the BIOS would probe the CPUs for SMP guests.  This tends to be
very unreliably because of startup timing issues.  By passing the number of
CPUs in the CMOS, the BIOS can detect the number of CPUs much more reliably.

(Anthony Liguori)


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4114 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 3 insertions, 0 deletions

diff --git a/hw/pc.c b/hw/pc.c
index 2a569c7..4fec2d4 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -213,6 +213,9 @@ static void cmos_init(int ram_size, const char *boot_device, BlockDriverState **
     rtc_set_memory(s, 0x34, val);
     rtc_set_memory(s, 0x35, val >> 8);
 
+    /* set the number of CPU */
+    rtc_set_memory(s, 0x5f, smp_cpus - 1);
+
     /* set boot devices, and disable floppy signature check if requested */
 #define PC_MAX_BOOT_DEVICES 3
     nbds = strlen(boot_device);