Adds memory measurement.

prototypes/base/include/pmm.hpp

@@ -30,4 +30,9 @@ public:
    * Frees a given page by pointer.
    */
   static void free(physical_t page);
+  
+  /**
+   * Returns the free memory.
+   */
+  static uint32_t getFreeMemory();
 };

prototypes/base/init.cpp

@@ -33,12 +33,14 @@ extern "C" void init(Structure const & data)
     if(mmap.length == 0) {
       continue;
     }
+    if(mmap.isFree() == false) {
+      continue;
+    }
     Console::main
       << "mmap: "
       << "start: " << hex(mmap.base) << ", length: " << hex(mmap.length)
       << ", " << mmap.entry_size
       << ", " << sizeof(mmap)
-      << ", free:" << mmap.isFree()
       << "\n";
     if(mmap.base > 0xFFFFFFFF) {
         Console::main << "mmap out of 4 gigabyte range." << "\n";
@@ -67,11 +69,23 @@ extern "C" void init(Structure const & data)
     ptr += 0x1000;
   }
   
+  auto freeMemory = PMM::getFreeMemory();
+  Console::main
+    << "Free: "
+    << (freeMemory >> 20) << "MB, "
+    << (freeMemory >> 10) << "KB, "
+    << (freeMemory >>  0) << "B, "
+    << (freeMemory >> 12) << "Pages\n";
+  
+  /*
   for(int i = 0; i < 10; i++) {
     bool success;
     physical_t page = PMM::alloc(success);
     Console::main << "allocated page " << i << " [" << success << "]: " << page << "\n";
   }
+  */
+  
+  
 }
 
 static_assert(sizeof(void*) == 4, "Target platform is not 32 bit.");

prototypes/base/src/pmm.cpp

@@ -96,3 +96,23 @@ void PMM::free(physical_t page)
   // Mark the selected bit as free.
   bitmap[idx] |= (1<<bit);
 }
+
+uint32_t PMM::getFreeMemory()
+{
+  uint32_t freeMemory = 0;
+  for(uint32_t idx = 0; idx < BitmapLength; idx++) {
+    // fast skip when no bit is set
+    if(bitmap[idx] == 0) {
+      continue;
+    }
+    for(uint32_t bit = 0; bit < 32; bit++) {
+      uint32_t mask = (1<<bit);
+      if((bitmap[idx] & mask) == 0) {
+        // If bit is not set, ignore the bit.
+        continue;
+      }
+      freeMemory += 0x1000; 
+    }
+  }
+  return freeMemory;
+}