m1x/x86_64: Implement processor primitives

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

src/m1x/include/arch/x86_64/prim.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * Provided under the BSD-3 clause
+ */
+
+#ifndef _MACHINE_PRIM_H_
+#define _MACHINE_PRIM_H_ 1
+
+#include <sys/types.h>
+#include <sys/cdefs.h>
+
+/* Hint to the processor that we are in a spinloop */
+#define hal_cpu_spinwait() \
+    __asmv("pause" ::: "memory")
+
+/* Halt the current processor core */
+#define hal_cpu_halt()  \
+    __asmv("hlt" ::: "memory")
+
+/*
+ * Atomic swap operation
+ *
+ * @p: Location to swap with `v`
+ * @v: Value to swap to `p`
+ */
+__always_inline static inline size_t
+hal_cpu_aswap(size_t *p, size_t v)
+{
+    size_t vret;
+
+    if (p == NULL) {
+        return 0;
+    }
+
+    vret = *(volatile size_t *)p;
+    __asmv(
+        "xchg %0, %1\n"
+        : "+m" (*p), "+r" (v)
+        :
+        : "memory"
+    );
+
+    return vret;
+}
+
+#endif  /* !_MACHINE_PRIM_H_ */

src/m1x/include/hal/cpu.h

@@ -6,6 +6,12 @@
 #ifndef _HAL_CPU_H_
 #define _HAL_CPU_H_ 1
 
+/*
+ * Each architecture is to implement their own version
+ * of the standard processor primitives.
+ */
+#include <machine/prim.h>
+
 /*
  * Initialize the current processor
  */

src/m1x/kern/Makefile

@@ -17,6 +17,7 @@ CFLAGS = 					\
 	-MMD					\
 	-I../../sdk/include/	\
 	-I../include/			\
+	-I../target/			\
 	-I../foreign/flanterm/src	\
 	-DPRINTF_DISABLE_SUPPORT_PTRDIFF_T \
 	-DPRINTF_DISABLE_SUPPORT_FLOAT		\