// vmm.h
// Author: Josh Holtrop
// Date: 09/30/03
// Rewritten from scratch: 12/23/03
// Modified: 03/02/04

#include "hos_defines.h"

#ifndef __HOS_VMM__
#define __HOS_VMM__ __HOS_VMM__

#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 {
	unsigned int	base;			//virtual base address
	unsigned int	size;			//size in bytes
	unsigned int	attributes;		//free/used/hole
	unsigned int	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(unsigned int bytes);
int	free(void *ptr);
void	vmm_map1(unsigned int virt, unsigned int physical);
void	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n);
void	vmm_unmap1(unsigned int virt);
void	vmm_unmapn(unsigned int virt, unsigned int n);
void	vmm_heb_init(HeapEntryBlock *heb);
void	*vmm_getFreeChunk(unsigned int bytes);
HeapEntry *vmm_nextHeapEntry();
unsigned int	vmm_heapEntriesLeft();
HeapEntry *vmm_getLastHeapEntry();
HeapEntry *vmm_getFirstUnusedHeapEntry();
HeapEntry *vmm_getFirstHoleHeapEntry(unsigned int minBytes);
void	vmm_addHeapEntryBlock();
int	vmm_moreCore(unsigned int bytes);
void	vmm_coalesceHeapEntry(HeapEntry *he);
HeapEntry *vmm_getHeapEntryByBase(unsigned int base);

#endif