From d8eaa13f2efc1eeca4e5f230d5a2d535aaf27338 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Fri, 2 Jan 2026 00:47:16 +0800
Subject: dev(file-system): establish VFS and Read-only FAT32 File System

---
 src/kernel/cxx.cc | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 src/kernel/cxx.cc

(limited to 'src/kernel/cxx.cc')

diff --git a/src/kernel/cxx.cc b/src/kernel/cxx.cc
new file mode 100644
index 0000000..f9541b5
--- /dev/null
+++ b/src/kernel/cxx.cc
@@ -0,0 +1,68 @@
+#include "common/types.h"
+#include "kernel/pmm.h"
+#include "drivers/uart.h"
+
+/*
+ * C++ Kernel Runtime Support
+ *
+ * * Strategy: Map directly to PMM::alloc_page().
+ * Pros: Simple, works immediately for VFS.
+ * Cons: Allocates 4KB for every object (wasteful for small objects),
+ * but acceptable for current stage.
+ */
+
+void *operator new(unsigned long size)
+{
+    // Safety check: PMM allocates 4096 bytes max per call
+    if (size > 4096)
+    {
+        Drivers::uart_puts("panic: new allocation too big (max 4096)\n");
+        while (1)
+            ;
+    }
+
+    void *p = PMM::alloc_page();
+    if (!p)
+    {
+        Drivers::uart_puts("panic: new out of memory\n");
+        while (1)
+            ;
+    }
+    // PMM::alloc_page returns zeroed memory usually,
+    // but standard 'new' doesn't guarantee it.
+    // The constructor will handle initialization.
+    return p;
+}
+
+void *operator new[](unsigned long size)
+{
+    return operator new(size);
+}
+
+void operator delete(void *p)
+{
+    if (p)
+        PMM::free_page(p);
+}
+
+void operator delete[](void *p)
+{
+    if (p)
+        PMM::free_page(p);
+}
+
+// C++14 Sized Deallocation (Required by modern compilers)
+// The compiler optimizes 'delete' calls to pass the size of the object
+void operator delete(void *p, unsigned long size)
+{
+    (void)size; // We ignore size because PMM always frees a full page
+    if (p)
+        PMM::free_page(p);
+}
+
+void operator delete[](void *p, unsigned long size)
+{
+    (void)size;
+    if (p)
+        PMM::free_page(p);
+}
\ No newline at end of file
-- 
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