stos/amd64: Add port I/O helpers

Signed-off-by: Chloe M. <chloe@mensia.org>

paw/stos/Makefile

@@ -10,7 +10,12 @@
 include ../mk/stos.mk
 
 .PHONY: all
-all: ke machine
+all: target ke machine
+
+.PHONY: target
+target:
+	mkdir -p target/machine/
+	rsync -avr head/arch/$(ST_TARGET_ARCH)/*.h target/machine/
 
 .PHONY: ke
 ke:

paw/stos/head/arch/amd64/pio.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2026, Chloe M.
+ * Provided under the BSD-3 clause.
+ *
+ * Description: Port I/O helpers
+ * Author:      Chloe M.
+ */
+
+#ifndef _MACHINE_PIO_H_
+#define _MACHINE_PIO_H_ 1
+
+#include <stdef.h>
+
+ALWAYS_INLINE static inline UCHAR
+MdInb(USHORT Port)
+{
+    UCHAR result;
+    ASMV("in %%dx, %%al" : "=a" (result) : "d" (Port));
+    return result;
+}
+
+ALWAYS_INLINE static inline USHORT
+MdInw(USHORT Port)
+{
+    USHORT Val;
+    ASMV("inw %w1, %w0" : "=a" (Val) : "Nd" (Port));
+    return Val;
+}
+
+ALWAYS_INLINE static inline ULONG
+MdInl(USHORT Port)
+{
+    ULONG Val;
+    ASMV("inl %w1, %0" : "=a" (Val) : "Nd" (Port));
+    return Val;
+}
+
+ALWAYS_INLINE static inline VOID
+MdOutb(USHORT Port, UCHAR Val)
+{
+    ASMV("out %%al, %%dx" : :"a" (Val), "d" (Port));
+}
+
+ALWAYS_INLINE static inline VOID
+MdOutw(USHORT Port, USHORT Val)
+{
+    ASMV("outw %w0, %w1" : : "a" (Val), "Nd" (Port));
+}
+
+ALWAYS_INLINE static inline VOID
+MdOutl(USHORT Port, ULONG Val)
+{
+    ASMV("outl %0, %w1" : : "a" (Val), "Nd" (Port));
+}
+
+#endif  /* !_MACHINE_PIO_H_ */

paw/stos/ke/Makefile

@@ -23,6 +23,7 @@ CFLAGS =			\
 	-DPRINTF_DISABLE_SUPPORT_PTRDIFF_T \
 	-DPRINTF_DISABLE_SUPPORT_FLOAT	   \
 	-I../head						   \
+	-I../target						   \
 	-I$(ST_PROJECT_ROOT)/paw/spkg/head \
 	-I$(ST_PROJECT_ROOT)/sdk/head	   \
 	-D_BOOT_PROTO="\"$(ST_BOOT_PROTOCOL)\""