--- /dev/null
+// X86 utility functions.
+//
+// Copyright (C) 2013 Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "x86.h" // __cpuid
+
+void
+cpuid(u32 index, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
+{
+ // Check for cpu id
+ u32 origflags = save_flags();
+ restore_flags(origflags ^ F_ID);
+ u32 newflags = save_flags();
+ restore_flags(origflags);
+
+ if (((origflags ^ newflags) & F_ID) != F_ID)
+ // no cpuid
+ *eax = *ebx = *ecx = *edx = 0;
+ else
+ __cpuid(index, eax, ebx, ecx, edx);
+}