Add page directory cloning, beginning of multitasking
diff --git a/src/kernel/kint.h b/src/kernel/kint.h
index d892f88..f70b22f 100644
--- a/src/kernel/kint.h
+++ b/src/kernel/kint.h
@@ -18,3 +18,6 @@
 #define NULL 0
 #define MIN(a, b) ((a)>(b)?(b):(a))
 #define MAX(a, b) ((a)>(b)?(a):(b))
+
+// Coerce into 1 or 0
+#define BOOL(a) (!(!(a)))