feat: Symmetric Multiprocessing, text editor improvements, merge doom libc, implement math functions

kernel/src/CppLib/Spinlock.hpp

@@ -15,4 +15,20 @@ namespace kcp {
         void Acquire();
         void Release();
     };
+
+    // Non-interrupt-disabling mutex for subsystems that are only called
+    // from process/syscall context (never from interrupt handlers).
+    // Keeps interrupts enabled while spinning and while held.
+    class Mutex {
+        std::atomic_flag flag{ATOMIC_FLAG_INIT};
+    public:
+        void Acquire() {
+            while (flag.test_and_set(std::memory_order_acquire)) {
+                asm volatile("pause");
+            }
+        }
+        void Release() {
+            flag.clear(std::memory_order_release);
+        }
+    };
 };