#ifndef MM_H
#define MM_H MM_H

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

#define KERNEL_CODE_SEGMENT 0x08
#define KERNEL_DATA_SEGMENT 0x10

typedef u32_t pagedirectory_entry_t;

#define NUM_PAGETABLE_ENTRIES (PAGE_SIZE / sizeof(pagedirectory_entry_t))

typedef pagedirectory_entry_t pagedirectory_t[NUM_PAGETABLE_ENTRIES];

typedef struct
{
    u64_t   base;
    u64_t   length;
} mm_mem_range_t;

/* http://courses.ece.illinois.edu/ece391/references/descriptors.pdf */
/* granularity: 0: limit in bytes; 1: limit in pages */
/* dpl: 0: system mode; 3: user mode */
/* normal: 0: TSS/LDT/call gate; 1: code/data segment */
/* code_seg: 0: data segment; 1: code segment */
#define MAKE_DESCRIPTOR(base, limit, granularity, dpl, normal, code_seg)       \
        (u64_t) ( ( (((u64_t) base) & 0xFF000000ull) << 32 ) /* base 31:24 */  \
                | ( (((u64_t) granularity) & 0x1ull) << 55 ) /* granularity */ \
                | ( ( (u64_t) 0x1ull) << 54 )                /* 32-bit */      \
                | ( (((u64_t) limit) & 0xF0000ull) << 32 )   /* limit 19:16 */ \
                | ( ( (u64_t) 0x1ull) << 47 )                /* present */     \
                | ( (((u64_t) dpl) & 0x3ull) << 45 )         /* dpl */         \
                | ( (((u64_t) normal) & 0x1ull) << 44 )      /* normal */      \
                | ( (((u64_t) code_seg) & 0x1ull) << 43 )    /* code seg */    \
                | ( ( (u64_t) 0x2ull) << 40 )                /* ? */           \
                | ( (((u64_t) base) & 0x00FFFFFFull) << 16)  /* base 23:00 */  \
                | ( (((u64_t) limit) & 0x0000FFFFull) ) )    /* limit 15:00 */

typedef u64_t descriptor_t;

void mm_record_mmap_entry(mb_mmap_t * mmap);
void mm_bootstrap();

int mm_early_map(u32_t virtual_address, u32_t physical_address,
                 u32_t user_mode, u32_t writable);
int mm_map(u32_t virtual_address, u32_t physical_address,
           u32_t user_mode, u32_t writable);

u32_t mm_early_page_alloc();
u32_t mm_page_alloc();

void mm_print_memory_map();

#endif