runtime: add cppruntime/perm

cppruntime/perm.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <cstdint>
+
+
+namespace helos {
+
+// Permission on block devices and files, in all-right Unix fashion.
+// This must be in-line with MAP_PROT_EXEC/WRITE/READ and other Unix perms.
+typedef uint16_t     Permission;
+constexpr Permission PermExecute = 1 << 0;
+constexpr Permission PermWrite   = 1 << 1;
+constexpr Permission PermRead    = 1 << 2;
+
+
+} // namespace helos

cppruntime/runtime.hpp

@@ -0,0 +1,5 @@
+#pragma once
+
+#include "../memory/memory.hpp"
+
+#include "perm.hpp"