Move source files to src/, add Makefile, fix all build and linkage errors, etc.

exosphere/src/utils.c

@@ -0,0 +1,18 @@
+#include "utils.h"
+
+void panic(uint32_t code) {
+    (void)code; /* TODO */
+}
+
+void generic_panic(void) {
+    /* TODO */
+}
+
+__attribute__((noinline)) bool overlaps(uint64_t as, uint64_t ae, uint64_t bs, uint64_t be)
+{
+    if(as <= bs && bs <= ae)
+        return true;
+    if(bs <= as && as <= be)
+        return true;
+    return false;
+}