Move include/malloc.h to include/gpxe/malloc.h, since everything in there

is now gPXE-specific.  (The standard malloc() et al have been in stdlib.h
for a while).

Add free memory counter.

src/core/heap.c

-#include <malloc.h>
+#include <gpxe/malloc.h>
 #include <gpxe/heap.h>
 
 /**

src/core/malloc.c

 #include <strings.h>
 #include <io.h>
 #include <gpxe/list.h>
-#include <malloc.h>
+#include <gpxe/malloc.h>
 
 /** @file
  *
 /** List of free memory blocks */
 static LIST_HEAD ( free_blocks );
 
+/** Total amount of free memory */
+size_t freemem;
+
 /**
  * Allocate a memory block
  *
 			 */
 			if ( pre_size < MIN_MEMBLOCK_SIZE )
 				list_del ( &pre->list );
+			/* Update total free memory */
+			freemem -= size;
+			/* Return allocated block */
 			DBG ( "Allocated [%p,%p)\n", block,
 			      ( ( ( void * ) block ) + size ) );
 			return block;
 		freeing->size += block->size;
 		list_del ( &block->list );
 	}
+
+	/* Update free memory counter */
+	freemem += size;
 }
 
 /**

src/include/malloc.h → src/include/gpxe/malloc.h

-#ifndef _MALLOC_H
-#define _MALLOC_H
+#ifndef _GPXE_MALLOC_H
+#define _GPXE_MALLOC_H
 
 #include <stdint.h>
 
 
 /*
  * Prototypes for the standard functions (malloc() et al) are in
- * stdlib.h.  Include <malloc.h> only if you need the non-standard
- * functions, such as malloc_dma().
+ * stdlib.h.  Include <gpxe/malloc.h> only if you need the
+ * non-standard functions, such as malloc_dma().
  *
  */
 #include <stdlib.h>
 
+extern size_t freemem;
+
 extern void * alloc_memblock ( size_t size, size_t align );
 extern void free_memblock ( void *ptr, size_t size );
 extern void mpopulate ( void *start, size_t len );
 	free_memblock ( ptr, size );
 }
 
-#endif /* _MALLOC_H */
+#endif /* _GPXE_MALLOC_H */

src/net/pkbuff.c

  */
 
 #include <stdint.h>
-#include <malloc.h>
+#include <gpxe/malloc.h>
 #include <gpxe/pkbuff.h>
 
 /** @file