spi/amd64: Add CPUID helpers

Signed-off-by: Ian Moffett <ian@mirocom.org>

.gitignore

@@ -6,3 +6,4 @@
 *.o
 /var
 /usr/src/boot/stand
+/usr/src/sp1/head/target

usr/src/sp1/Makefile

@@ -10,7 +10,12 @@
 #
 
 .PHONY: all
-all: common $(ARCH)
+all: target common $(ARCH)
+
+.PHONY: target
+target:
+	mkdir -p head/target/machine/
+	rsync -avr head/$(ARCH)/*.h head/target/machine/
 
 .PHONY: common
 common:

usr/src/sp1/amd64/Makefile

@@ -27,7 +27,8 @@ LD =				\
 CFLAGS = 					\
 	$(SYS_CFLAGS)   		\
 	-I../../head    		\
-	-I../../sp1/head\
+	-I../../sp1/head/target \
+	-I../../sp1/head		\
 	-D_KERNEL
 
 .PHONY: all

usr/src/sp1/common/Makefile

@@ -22,6 +22,7 @@ CC = ../../../../$(SYS_CC)
 CFLAGS = 			\
 	$(SYS_CFLAGS)   \
 	-I../head		\
+	-I../head/target/ \
 	-I../../head	\
 	-I../ext/flanterm/src/ \
 	-D_KERNEL		\

usr/src/sp1/head/amd64/cpuid.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#ifndef _MACHINE_CPUID_H_
+#define _MACHINE_CPUID_H_ 1
+
+#include <sys/cdefs.h>
+
+#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_ */