/*
 *	========================================================
 *
 *	hCore
 * 	Copyright Mahrouss Logic, all rights reserved.
 *
 * 	========================================================
 */

#include <HALKit/AMD64/HalPageAlloc.hpp>
#include <NewKit/Defines.hpp>
#include <NewKit/Panic.hpp>

// this files handles paging.

static hCore::UIntPtr kPagePtr = 0x0900000;
static hCore::SizeT kPageCnt = 0UL;

namespace hCore
{
    namespace HAL
    {
        static auto hal_try_alloc_new_page(SizeT sz, Boolean rw, Boolean user) -> PageTable64*
        {
            char *ptr = &(reinterpret_cast<char*>(kPagePtr))[kPageCnt + 1];

            PageTable64 *pte = reinterpret_cast<PageTable64*>(ptr);
            pte->Rw = rw;
            pte->User = user;
            pte->Present = true;

            return pte;
        }

        auto hal_alloc_page(SizeT sz, Boolean rw, Boolean user) -> PageTable64*
        {
            for (SizeT i = 0; i < kPageCnt; ++i)
            {
                PageTable64 *pte = (reinterpret_cast<PageTable64*>(&kPagePtr) + i);

                if (!pte->Present) {
                    pte->User = user;
                    pte->Rw = rw;
                    pte->Present = true;

                    return pte;
                }
            }

            return hal_try_alloc_new_page(sz, rw, user);
        }

        auto hal_create_page(Boolean rw, Boolean user) -> UIntPtr
        {
            PageTable64 *new_pte = hal_alloc_page(sizeof(PageTable64), rw, user);
            MUST_PASS(new_pte);

            return reinterpret_cast<UIntPtr>(new_pte);
        }
    } // namespace HAL
} // namespace hCore