diff --git a/paw/stos/head/arch/amd64/cpuid.h b/paw/stos/head/arch/amd64/cpuid.h
new file mode 100644
index 0000000..033c271
--- /dev/null
+++ b/paw/stos/head/arch/amd64/cpuid.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2026, Chloe M.
+ * Provided under the BSD-3 clause.
+ *
+ * Description: CPUID helper
+ * Author:      Chloe M.
+ */
+
+#ifndef _MACHINE_CPUID_H_
+#define _MACHINE_CPUID_H_ 1
+
+#define CPUID(level, a, b, c, d)                        \
+    ASMV("cpuid\n\t"                                    \
+            : "=a" (a), "=b" (b), "=c" (c), "=d" (d)    \
+            : "0" (level))
+
+#endif  /* !_MACHINE_CPUID_H_ */