#include "pagetable.h"

void load_cr3( void* cr3_value ) {
    asm volatile("mov %0, %%cr3" :: "r"((uint64_t)cr3_value) : "memory");
}
void create_basic_page_table(uintptr_t base){
    //pagedirectory_entry_t *l4 = (pagedirectory_entry_t *)(base + (0 * 4096));
    //pagedirectory_entry_t *l3 = (pagedirectory_entry_t *)(base + (1 * 4096));
    //pagedirectory_entry_t *l2 = (pagedirectory_entry_t *)(base + (2 * 4096));
    //pagetable_entry_t     *l1 = (pagetable_entry_t *)    (base + (7 * 4096));
    four_lvl_paging_t* table = (four_lvl_paging_t*)base;

    table->l4.entries[0] = {
        .present = 1,
        .write = 1,
        .user = 1,
        .address = (uintptr_t)&(table->l3) >> 12,
    };

    table->l3.entries[0] = {
        .present = 1,
        .write = 1,
        .user = 1,
        .address = (uintptr_t)&(table->l2) >> 12,
    };

    for(uint32_t i=0; i<sizeof(table->l1)/sizeof(table->l1[0]); i++){
        table->l2.entries[i] = {
            .present = 1,
            .write = 1,
            .user = 1,
            .address = (uintptr_t)&(table->l1[i]) >> 12,
        };
    }

    //kernel memory
    for(uintptr_t i=0; i<0x4000000/4096; i++){
        table->l1[i/512].entries[i%512] = {
            .present = 1,
            .write = 1,
            .user = 0,
            .address = i,
        };
    }

    //add ioapic address to pagetable
    table->l3.entries[3] = {
        .present = 1,
        .write = 1,
        .user = 1,
        .address = (uintptr_t)&(table->l2_apic) >> 12,
    };
    table->l2_apic.entries[502] = {
        .present = 1,
        .write = 1,
        .user = 1,
        .address = (uintptr_t)&(table->ioapic) >> 12,
    };
    table->ioapic.entries[0] = {
        .present = 1,
        .write = 1,
        .user = 0,
        .address = 0xFEC00,
    };

    //lapic
    table->l2_apic.entries[503] = {
        .present = 1,
        .write = 1,
        .user = 1,
        .address = (uintptr_t)&(table->lapic) >> 12,
    };
    table->lapic.entries[0] = {
        .present = 1,
        .write = 1,
        .user = 0,
        .address = 0xFEE00,
    };


    //unmap 0 page
    table->l1[0].entries[0].present = 0;

    ////map ioapic
    //uintptr_t ioapic_page = 0xfec00000 >> 12;
    //table->l1[ioapic_page/512].entries[ioapic_page%512].address = ioapic_page;
    //table->l1[ioapic_page/512].entries[ioapic_page%512].present = 1;
    //table->l1[ioapic_page/512].entries[ioapic_page%512].write = 1;
}