diff --git a/prototypes/base/init.cpp b/prototypes/base/init.cpp
index 3d062e5..fbed94a 100644
--- a/prototypes/base/init.cpp
+++ b/prototypes/base/init.cpp
@@ -10,6 +10,12 @@
 using namespace multiboot;
 using namespace console_tools;
 
+struct dummy;
+
+// Symbols generated by linker, no useful content in there...
+extern dummy kernelStartMarker;
+extern dummy kernelEndMarker;
+
 extern "C" void init(Structure const & data)
 {
 	Console::main
@@ -38,17 +44,29 @@ extern "C" void init(Structure const & data)
         Console::main << "mmap out of 4 gigabyte range." << "\n";
         continue;
     }    
-    if(mmap.isFree()) {      
+    if(mmap.isFree()) {
       // Mark all free memory free...
-      uintptr_t lower = (mmap.base + 0x0FFF) & 0xFFFFF000; // align at upper 4096
-      uintptr_t upper = (mmap.base + mmap.length) & 0xFFFFF000; // align at lower 4096
-      while (lower < upper) {
-          PMM::markFree(physical_t(lower));
-          lower += 0x1000;
+      physical_t lower = physical_t(mmap.base).alignUpper(4096);
+      physical_t upper = physical_t(mmap.base + mmap.length).alignLower(4096);
+      
+      uint32_t ptr = lower.numeric();
+      while (ptr < upper.numeric()) {
+        PMM::markFree(physical_t(ptr));
+        ptr += 0x1000;
       }
     }
   }
   
+  // Mark all memory used by the kernel used...
+  physical_t lower = physical_t(&kernelStartMarker).alignLower(4096);
+  physical_t upper = physical_t(&kernelEndMarker).alignUpper(4096);
+  
+  uint32_t ptr = lower.numeric();
+  while (ptr < upper.numeric()) {
+    PMM::markUsed(physical_t(ptr));
+    ptr += 0x1000;
+  }
+  
   for(int i = 0; i < 10; i++) {
     bool success;
     physical_t page = PMM::alloc(success);
diff --git a/prototypes/base/linker.ld b/prototypes/base/linker.ld
index fd6acd8..ed97bd5 100644
--- a/prototypes/base/linker.ld
+++ b/prototypes/base/linker.ld
@@ -6,7 +6,7 @@ SECTIONS
 {
     . = 0x100000;
 
-    kernelStart = .;
+    kernelStartMarker = .;
 
     .text : {
         *(multiboot)
@@ -33,5 +33,5 @@ SECTIONS
 
     /* Align the end of the kernel to the page size */
     . = ALIGN(4096);
-    kernelEnd = .;
+    kernelEndMarker = .;
 }
\ No newline at end of file