From 4380590af239a44fbde17f3df9afbdcb73e0000e Mon Sep 17 00:00:00 2001
From: Drew Galbraith <dgalbraith33@gmail.com>
Date: Thu, 18 May 2023 11:29:44 -0700
Subject: [PATCH] Add new and delete operator implementations to the kernel
 heap.

For now delete does nothing.
---
 zion/CMakeLists.txt         |  4 +++-
 zion/memory/kernel_heap.cpp | 20 +++++++++++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/zion/CMakeLists.txt b/zion/CMakeLists.txt
index 2f858cb..5bd066e 100644
--- a/zion/CMakeLists.txt
+++ b/zion/CMakeLists.txt
@@ -17,12 +17,14 @@ target_include_directories(zion
 
 # -c -- Don't run the linker (only necessary for the assembler)
 # -ffreestanding
+# -fno-rtti -- No runtime type information (might mess with polymorphism?)
+# -fno-exceptions -- Disable exceptions.
 # -nostdlib -- Don't include the standard library.
 # -mabi=sysv -- Explicitly specify the ABI since we will rely on it.
 # -mno-red-zone -- Don't put data below the stack pointer (clobbered by interrupts).
 # -mcmodel=kernel -- Assume the kernel code is running in the higher half.
 # -mgeneral-regs-only -- Prevent GCC from using a whole host of nonsense registers (that we have to enable).
-set(_Z_COMPILE_FLAGS "${CMAKE_CXX_FLAGS} -c -ffreestanding -nostdlib -mabi=sysv -mno-red-zone -mcmodel=kernel -mgeneral-regs-only")
+set(_Z_COMPILE_FLAGS "${CMAKE_CXX_FLAGS} -c -ffreestanding -fno-rtti -fno-exceptions -nostdlib -mabi=sysv -mno-red-zone -mcmodel=kernel -mgeneral-regs-only")
 
 set(_Z_LINK_SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/linker.ld")
 
diff --git a/zion/memory/kernel_heap.cpp b/zion/memory/kernel_heap.cpp
index 311aae1..d318fea 100644
--- a/zion/memory/kernel_heap.cpp
+++ b/zion/memory/kernel_heap.cpp
@@ -3,8 +3,22 @@
 #include "debug/debug.h"
 #include "memory/paging_util.h"
 
+namespace {
+
+static KernelHeap* gKernelHeap = nullptr;
+
+KernelHeap& GetKernelHeap() {
+  if (!gKernelHeap) {
+    panic("Kernel Heap not initialized.");
+  }
+  return *gKernelHeap;
+}
+}  // namespace
+
 KernelHeap::KernelHeap(uint64_t lower_bound, uint64_t upper_bound)
-    : next_addr_(lower_bound), upper_bound_(upper_bound) {}
+    : next_addr_(lower_bound), upper_bound_(upper_bound) {
+  gKernelHeap = this;
+}
 
 void* KernelHeap::Allocate(uint64_t size) {
   if (next_addr_ + size >= upper_bound_) {
@@ -15,3 +29,7 @@ void* KernelHeap::Allocate(uint64_t size) {
   next_addr_ += size;
   return reinterpret_cast<void*>(address);
 }
+
+void* operator new(uint64_t size) { return GetKernelHeap().Allocate(size); }
+
+void operator delete(void*, uint64_t) {}