kernel/inc/mm/page_map.h

#ifndef NOX_PAGE_MAP_H
#define NOX_PAGE_MAP_H

#include "utils/stdtypes.h"

#define VIRTUAL_ADDRESS_MAX 0x1000000000000     // 256 TB (the limit of PML4s)

typedef enum {
    PM_FLAG_PRESENT         = 0b0000000000000001,   // 1 << 0
    PM_FLAG_READ_WRITE      = 0b0000000000000010,   // 1 << 1
    PM_FLAG_USER_SUPER      = 0b0000000000000100,   // 1 << 2
    PM_FLAG_WRITE_THROUGH   = 0b0000000000001000,   // 1 << 3
    PM_FLAG_CACHE_DISABLED  = 0b0000000000010000,   // 1 << 4
    PM_FLAG_ACCESSED        = 0b0000000000100000,   // 1 << 5
    PM_FLAG_DIRTY           = 0b0000000001000000,   // 1 << 6
    PM_FLAG_LARGER_PAGES    = 0b0000000010000000,   // 1 << 7
    PM_FLAG_CUSTOM_0        = 0b0000001000000000,   // 1 << 9
    PM_FLAG_CUSTOM_1        = 0b0000010000000000,   // 1 << 10
    PM_FLAG_CUSTOM_2        = 0b0000100000000000,   // 1 << 11
    PM_FLAG_NO_EXECUTE      = 0x8000000000000000    // 1 << 63
} page_map_flag_E;

typedef struct {
    uint64_t entries[512];
}__attribute__((aligned(0x1000))) page_map_T;

page_map_T*         page_map_create                 ();
extern page_map_T*  page_map_fetch_current          ();
extern void         page_map_load                   (page_map_T* page_map);
void                page_map_map_memory             (page_map_T* page_map, void* virtual_address, void* physical_address, uint64_t flags);
void                page_map_unmap_memory           (page_map_T* page_map, void* virtual_address);
bool                page_map_check_memory           (page_map_T* page_map, void* virtual_address);
void*               page_map_get_physical_address   (page_map_T* page_map, void* virtual_address);
void                page_map_destruct               (page_map_T* page_map);
void                page_map_dump_info              (page_map_T* page_map);

void                page_map_entry_set_flags        (uint64_t* entry, uint64_t flags);
bool                page_map_entry_get_flag         (uint64_t* entry, page_map_flag_E flag);
void                page_map_entry_set_address      (uint64_t* entry, void* address);
void*               page_map_entry_get_address      (uint64_t* entry);

void                paging_init                     ();

extern page_map_T* g_kernel_page_map;

#endif //NOX_PAGE_MAP_H