// vmm.h
// Author: Josh Holtrop
// Date: 09/30/03
// Rewritten from scratch: 12/23/03, 07/13/04
// Modified: 07/30/04

#ifndef __HOS_VMM__
#define __HOS_VMM__ __HOS_VMM__

#include "hos_defines.h"
#include "multiboot.h"

#define VMM_HE_TYPES	4		//4 types of heap entries
#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/wilderness) section of virtual memory

#define	VMM_MALLOC_GRANULARITY	4	//a power of 2, granularity for all memory requests
#define VMM_MALLOC_GRAN_MASK	VMM_MALLOC_GRANULARITY-1	//mask for determining how much of a request is past granularity


typedef struct {
	void	*base;			//virtual base address
	u32_t	length;			//size in bytes
	void	*next;			//link to next HeapEntry
	void	*prev;			//link to previous HeapEntry
} __attribute__((packed)) HeapEntry_t;

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

typedef struct {
	int	count;
	HeapEntry_t *head;
} HeapEntryQueue_t;


void	vmm_init();
void	*kmalloc(u32_t size);
int	kfree(void *addr);
void	*vmm_palloc();
int	vmm_pfree(void *addr);
void	*kcalloc(unsigned int number, unsigned int size);

#endif