kernel: Reworking kernel to support virtual memory.

Signed-off-by: Amlal El Mahrouss <amlal@el-mahrouss-logic.com>

1 files changed, 23 insertions, 68 deletions

diff --git a/Private/Source/KernelHeap.cxx b/Private/Source/KernelHeap.cxx
index e7dd09ed..359e3cbd 100644
--- a/Private/Source/KernelHeap.cxx
+++ b/Private/Source/KernelHeap.cxx
@@ -5,50 +5,35 @@
 ------------------------------------------- */
 
 #include <NewKit/Crc32.hpp>
-#include <NewKit/KernelHeap.hpp>
+#include <KernelKit/KernelHeap.hpp>
+#include <NewKit/PageManager.hpp>
 
-//! @file KernelHeap.cpp
+//! @file KernelHeap.cxx
 //! @brief Kernel allocator.
 
-#define kHeapMaxWrappers (4096 * 8)
-#define kHeapMagic 0xAA55
+#define kHeapMagic 0xD4D7
 
 namespace HCore {
-STATIC Ref<PTEWrapper *> kWrapperList[kHeapMaxWrappers];
-STATIC SizeT kHeapCount = 0UL;
-STATIC Ref<PTEWrapper *> kLastWrapper;
-STATIC PageManager kPageManager;
+STATIC SizeT            kHeapCount = 0UL;
+STATIC Ref<PTEWrapper>  kHeapLastWrapper;
+STATIC PageManager      kHeapPageManager;
 
 namespace Detail {
 /// @brief Kernel heap information block.
-/// Located before the address.
-/// | HIB |                ADDRESS                |
+/// Located before the address bytes.
+/// | HIB |  ADDRESS  |
 struct HeapInformationBlock final {
-  UInt16 hMagic;
+  UInt16  hMagic;
   Boolean hPresent;
-  Int32 hCRC32;
-  Int64 hSizeAddress;
-  VoidPtr hAddress;
+  Int32   hCRC32;
+  Int64   hSizeAddress;
+  UIntPtr hAddress;
 };
 
 typedef HeapInformationBlock *HeapInformationBlockPtr;
-
-STATIC VoidPtr ke_find_heap(const SizeT &sz, const bool rw, const bool user) {
-  for (SizeT indexWrapper = 0; indexWrapper < kHeapMaxWrappers;
-       ++indexWrapper) {
-    if (!kWrapperList[indexWrapper]->Present()) {
-      kWrapperList[indexWrapper]
-          ->Reclaim(); /* very straight-forward as you can see. */
-      return reinterpret_cast<VoidPtr>(
-          kWrapperList[indexWrapper]->VirtualAddress());
-    }
-  }
-
-  return nullptr;
-}
 }  // namespace Detail
 
-/// @brief Allocate pointer.
+/// @brief allocate chunk of memory.
 /// @param sz size of pointer
 /// @param rw read write (true to enable it)
 /// @param user is it accesible by user processes?
@@ -56,28 +41,21 @@ STATIC VoidPtr ke_find_heap(const SizeT &sz, const bool rw, const bool user) {
 VoidPtr ke_new_ke_heap(SizeT sz, const bool rw, const bool user) {
   if (sz == 0) ++sz;
 
-  if (auto ptr = Detail::ke_find_heap(sz, rw, user); ptr) return ptr;
-
-  Ref<PTEWrapper *> wrapper = kPageManager.Request(user, rw, false);
-
-  Ref<PageManager> refMan(kPageManager);
-  wrapper->FlushTLB(refMan);
-
-  kLastWrapper = wrapper;
+  auto wrapper = kHeapPageManager.Request(rw, user, false);
+  kHeapLastWrapper = wrapper;
 
   Detail::HeapInformationBlockPtr heapInfo =
       reinterpret_cast<Detail::HeapInformationBlockPtr>(
-          wrapper->VirtualAddress());
+          wrapper.VirtualAddress());
 
   heapInfo->hSizeAddress = sz;
   heapInfo->hMagic = kHeapMagic;
-  heapInfo->hCRC32 = ke_calculate_crc32((Char *)wrapper->VirtualAddress(), sz);
-  heapInfo->hAddress = (VoidPtr)wrapper->VirtualAddress();
+  heapInfo->hCRC32 = 0; // dont fill it for now.
+  heapInfo->hAddress = wrapper.VirtualAddress();
 
-  kWrapperList[kHeapCount] = wrapper;
   ++kHeapCount;
 
-  return reinterpret_cast<VoidPtr>(wrapper->VirtualAddress() +
+  return reinterpret_cast<VoidPtr>(wrapper.VirtualAddress() +
                                    sizeof(Detail::HeapInformationBlock));
 }
 
@@ -90,35 +68,12 @@ Int32 ke_delete_ke_heap(VoidPtr ptr) {
         reinterpret_cast<Detail::HeapInformationBlockPtr>(ptr) -
         sizeof(Detail::HeapInformationBlock);
 
-    if (kLastWrapper && virtualAddress->hMagic == kHeapMagic &&
-        (UIntPtr)virtualAddress->hAddress == kLastWrapper->VirtualAddress()) {
-      if (kPageManager.Free(kLastWrapper)) {
+    if (kHeapLastWrapper && virtualAddress->hMagic == kHeapMagic &&
+        virtualAddress->hAddress == kHeapLastWrapper.Leak().VirtualAddress()) {
         virtualAddress->hSizeAddress = 0UL;
         virtualAddress->hPresent = false;
 
-        return true;
-      }
-
-      return false;
-    }
-
-    Ref<PTEWrapper *> wrapper{nullptr};
-
-    for (SizeT indexWrapper = 0; indexWrapper < kHeapCount; ++indexWrapper) {
-      if (kWrapperList[indexWrapper]->VirtualAddress() ==
-          (UIntPtr)virtualAddress->hAddress) {
-        wrapper = kWrapperList[indexWrapper];
-
-        // if page is no more, then mark it also as non executable.
-        if (kPageManager.Free(wrapper)) {
-          virtualAddress->hSizeAddress = 0UL;
-          virtualAddress->hPresent = false;
-
-          return true;
-        }
-
-        return false;
-      }
+      return true;
     }
   }