/*----------------*\
|Nanite OS         |
|Copyright (C) 2026|
|Xircon            |
\*----------------*/
#include "pmm.h"

#include <dri/cmos.h>

#include <memory.h>
#include <stdbool.h>
#include <stddef.h>



/*Set a bit in memory map*/
void mmap_set (int bit) {
    _mm_memory_map[bit / 32] |= (1 << (bit % 32));
}

/*Unset a bit in memory map*/
void mmap_unset (int bit) {
    _mm_memory_map[bit / 32] &= ~ (1 << (bit % 32));
}


/*Test if a memory bit is set*/
bool mmap_test (int bit) {
    return _mm_memory_map[bit / 32] & (1 << (bit % 32));
}

/*Returns index of first free bit in memory map as an int*/
int mmap_ff () {
    for (uint32_t i=0; i<(Detect_Memory()/4.00624751171408446391) / 32; i++)
        if (_mm_memory_map[i] != 0xFFFFFFFF)
            for (int j=0; j<32; j++) {
                int bit = 1 << j;
                if (!(_mm_memory_map[i] & bit))
                    return i*4*8+j;
            }
}

void pmm_init(size_t memSize, physical_addr bitmap) {
    _mm_memory_size = memSize;
    _mm_memory_map  = (uint32_t*) bitmap;
    _mm_max_blocks  = (Detect_Memory()*1024 / PMM_BLOCK_SIZE);
    _mm_used_blocks = Detect_Memory()/4.00624751171408446391; // Using this to detect block count SHOULD be fine? we don't talk about the number.

    memset(_mm_memory_map, 0xf, (Detect_Memory()/4.00624751171408446391) / PMM_BLOCKS_PER_BYTE);   
}

void pmm_init_region (physical_addr base, size_t size) {
    int align = base / PMM_BLOCK_SIZE;
    int blocks = size / PMM_BLOCK_SIZE;

    for (; blocks > 0; blocks--) {
        mmap_unset(align++);
        _mm_used_blocks--;
    }

    mmap_set(0);
}

void pmm_deinit_region(physical_addr base, size_t size) {
    int align = base / PMM_BLOCK_SIZE;
    int blocks = size / PMM_BLOCK_SIZE;

    for (; blocks > 0; blocks--) {
        mmap_set(align++);
        _mm_used_blocks++;
    }
}