// vmm.h
// Author: Josh Holtrop
// Date: 09/30/03
// Rewritten from scratch: 12/23/03
// Modified: 12/30/03


#define	VMM_HE_UNUSED	0		//available entry
#define	VMM_HE_FREE	1		//free section of memory
#define	VMM_HE_USED	2		//used section of memory
#define	VMM_HE_HOLE	3		//a "hole" (unmapped) section of virtual memory
#define	VMM_HE_HEB	4		//HeapEntryBlock

#define	VMM_MALLOC_GRANULARITY	4	//granularity for all memory requests

typedef struct {
	dword	base;			//virtual base address
	dword	size;			//size in bytes
	dword	attributes;		//free/used/hole
	dword	link;			//link to next HeapEntry
} __attribute__((packed)) HeapEntry;


typedef struct {
	HeapEntry	entry[256];	//256 HeapEntry objects = 4kb (1 page)
} __attribute__((packed)) HeapEntryBlock;


void	vmm_init();
void   *malloc(dword bytes);
int	free(void *ptr);
void	vmm_map1(dword virt, dword physical);
void	vmm_mapn(dword virt, dword physical, dword n);
void	vmm_unmap1(dword virt);
void	vmm_unmapn(dword virt, dword n);
void	vmm_heb_init(HeapEntryBlock *heb);
void	*vmm_getFreeChunk(dword bytes);
HeapEntry *vmm_nextHeapEntry();
dword	vmm_heapEntriesLeft();
HeapEntry *vmm_getLastHeapEntry();
HeapEntry *vmm_getFirstUnusedHeapEntry();
HeapEntry *vmm_getFirstHoleHeapEntry(dword minBytes);
void	vmm_addHeapEntryBlock();
int	vmm_moreCore(dword bytes);
void	vmm_coalesceHeapEntry(HeapEntry *he);
HeapEntry *vmm_getHeapEntryByBase(dword base);


HeapEntry *firstHeapEntry = (HeapEntry *)0xD0000000;	//this is where heap memory starts