user thread/process and elf loader stub

src/include/string/strerror.c

@@ -0,0 +1,16 @@
+#include <string.h>
+
+static char* strs[] = {
+	"No error",
+	"Not a directory",
+	"No such device",
+	"Out of memory",
+	"Invalid",
+	"Function unimplemented",
+	"File already exists",
+	"No such file or directory"
+};
+
+char* strerror(int errnum){
+	return strs[errnum];
+}