2 files changed, 22 insertions, 0 deletions
diff --git a/arm9/lib/include/MI_swap.h b/arm9/lib/include/MI_swap.h
new file mode 100644
index 00000000..433b5804
--- /dev/null
+++ b/arm9/lib/include/MI_swap.h
@@ -0,0 +1,6 @@
+#ifndef NITRO_MI_SWAP_H_
+#define NITRO_MI_SWAP_H_
+
+u32 MI_SwapWord(u32 setData, volatile u32 * destp);
+
+#endif //NITRO_MI_SWAP_H_
diff --git a/arm9/lib/src/MI_swap.c b/arm9/lib/src/MI_swap.c
new file mode 100644
index 00000000..b72e1386
--- /dev/null
+++ b/arm9/lib/src/MI_swap.c
@@ -0,0 +1,16 @@
+#include "global.h"
+#include "MI_swap.h"
+
+/*
+ * Exchange 32 bits of data between register and memory.
+ *
+ * The SDK also defines an 8-bit version of this routine,
+ * but it is not linked in pokediamond.
+ */
+
+asm
+u32 MI_SwapWord(register u32 setData, register vu32 * destp)
+{
+    swp setData, setData, [destp]
+    bx lr
+}