1 files changed, 7 insertions, 2 deletions

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 957a47aec64e..4dac2f68ed4a 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -292,8 +292,8 @@ default_entry:
  *      be using the global pages. 
  *
  *      NOTE! If we are on a 486 we may have no cr4 at all!
- *      Specifically, cr4 exists if and only if CPUID exists,
- *      which in turn exists if and only if EFLAGS.ID exists.
+ *      Specifically, cr4 exists if and only if CPUID exists
+ *      and has flags other than the FPU flag set.
  */
         movl $X86_EFLAGS_ID,%ecx
         pushl %ecx
@@ -308,6 +308,11 @@ default_entry:
         testl %ecx,%eax
         jz 6f                   # No ID flag = no CPUID = no CR4
 
+        movl $1,%eax
+        cpuid
+        andl $~1,%edx           # Ignore CPUID.FPU
+        jz 6f                   # No flags or only CPUID.FPU = no CR4
+
         movl pa(mmu_cr4_features),%eax
         movl %eax,%cr4