feat: add minimal C++ ABI stubs for freestanding kernel

2 files changed, 39 insertions, 14 deletions

diff --git a/na/lib/cxx_abi.cc b/na/lib/cxx_abi.cc
new file mode 100644
index 0000000..1ad9d4d
--- /dev/null
+++ b/na/lib/cxx_abi.cc
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * cxx_abi.cc — Minimal C++ ABI stubs for freestanding kernel
+ *
+ * Provides symbols that the compiler/linker expects from the C++
+ * runtime library.  All error paths are fatal (kernel_panic).
+ *
+ * Reference: docs/specs/cpp_runtime.md
+ */
+
+#include <lume/panic.h>
+
+/* Pure virtual function call trap.
+ * Generated by the compiler in vtable entries for pure virtual methods.
+ * Reaching this means a derived class failed to implement a pure virtual. */
+extern "C" void __cxa_pure_virtual()
+{
+    kernel_panic("pure virtual function call");
+}
+
+/* Global destructor registration.
+ * The kernel does not support global object destruction — all global
+ * objects use Placement New with explicit lifetime management.
+ * If the compiler emits a call to this, it indicates a code violation. */
+extern "C" int __cxa_atexit(void (*)(void*), void*, void*)
+{
+    kernel_panic("__cxa_atexit called in kernel");
+    return 0; // unreachable
+}
+
+/* DSO handle — required by __cxa_atexit ABI.
+ * The kernel is statically linked; this symbol just needs to exist. */
+extern "C" {
+void* __dso_handle __attribute__((visibility("hidden"))) = nullptr;
+}
diff --git a/na/lib/panic.cc b/na/lib/panic.cc
index 4745272..753f910 100644
--- a/na/lib/panic.cc
+++ b/na/lib/panic.cc
@@ -11,21 +11,9 @@
  */
 
 #include <lume/types.h>
+#include <lume/addr.h>
 #include <arch/cpu.h>
-
-// Minimal direct UART output (same as main.cc early boot)
-// This can be used by other early-boot code before console_init()
-
-constexpr uint64 kUart0VA = 0x10000000UL + 0xFFFFFFC000000000ULL;
-
-extern "C" void early_putc(char c) {
-    volatile auto* uart = reinterpret_cast<volatile uint8*>(kUart0VA);
-    *uart = static_cast<uint8>(c);
-}
-
-extern "C" void early_puts(const char* s) {
-    while (*s) early_putc(*s++);
-}
+#include <lume/console.h>
 
 extern "C" [[noreturn]] void kernel_panic(const char* msg, const char* detail) {
     arch::cpu::intr_off();