mango/arch/x86_64/include/arch/paging.h

#ifndef ARCH_PAGING_H_
#define ARCH_PAGING_H_

#include <mango/types.h>
#include <mango/compiler.h>

#ifdef __cplusplus
extern "C" {
#endif

#define PTE_PRESENT      0x01ULL
#define PTE_RW           0x02ULL
#define PTE_USR          0x04ULL
#define PTE_WRITETHROUGH 0x08ULL
#define PTE_NOCACHE      0x10ULL
#define PTE_PAGESIZE     0x80ULL
#define PTE_NX           0x8000000000000000ULL

typedef phys_addr_t pml4t_ptr_t;
typedef uint64_t pte_t;

struct pml4t {
	phys_addr_t p_entries[512];
} __packed;

struct pdpt {
	union {
		/* 4KiB and 2MiB pages */
		phys_addr_t p_entries[512];
		/* 1GiB pages */
		pte_t p_pages[512];
	};
} __packed;

struct pdir {
	union {
		/* 4KiB pages */
		phys_addr_t p_entries[512];
		/* 2MiB pages */
		pte_t p_pages[512];
	};
} __packed;

struct ptab {
	pte_t p_pages[512];
} __packed;

enum page_size {
	PS_4K,
	PS_2M,
	PS_1G,
};

/* returns 1 if gigabyte pages are supported by the CPU, 0 otherwise.
   defined in pmap_ctrl.S */
extern int gigabyte_pages(void);
extern int enable_nx(void);

#ifdef __cplusplus
}
#endif

#endif