//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:         Mapping and checking memory related functions               //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2019 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K is free software: you can redistribute it and/or modify              //
//  it under the terms of the GNU General Public License as published by      //
//  the Free Software Foundation, either version 3 of the License, or         //
//  any later version.                                                        //
//                                                                            //
//  OS/K is distributed in the hope that it will be useful,                   //
//  but WITHOUT ANY WARRANTY//without even the implied warranty of            //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
//  GNU General Public License for more details.                              //
//                                                                            //
//  You should have received a copy of the GNU General Public License         //
//  along with OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#include <mm/mm.h>

ulong gdtEntries[2] =
{
    (0L),                                    // NULL descriptor
    ((1L<<43) | (1L<<44) | (1L<<47) | (1L<<53)) // KERNEL CS 0x8
};


//Tss_t tssEntry = { 0 };
GdtPtr_t gdtPtr;

/* static void SetGdtEntry(int index, uint base, uint limit, uchar access) */
/* { */
/*     gdtEntries[index].lowBase      = (base & 0xFFFF); */
/*     gdtEntries[index].middleBase   = (base >> 16) & 0xFF; */
/*     gdtEntries[index].highBase     = (base >> 24) & 0xFF; */

/*     gdtEntries[index].lowLimit     = (limit & 0xFFFF); */
/*     gdtEntries[index].granularity  = (limit >> 16) & 0x0F; */

/*     gdtEntries[index].granularity |= 0xA0; */

/*     // 0x10 is system */
/*     // 0x80 is present */
/*     gdtEntries[index].access       = access | 0x10 | 0x80; */
/* } */

/* static void SetTssEntry(uchar index, ulong base, ulong limit) */
/* { */
/*     TssDescriptor_t tssDesc = { 0 }; */

/*     tssDesc.limitLow = limit & 0xffff; */
/*     tssDesc.size = (limit >> 16) & 0xf; */

/*     tssDesc.base00 = base & 0xffff; */
/*     tssDesc.base16 = (base >> 16) & 0xff; */
/*     tssDesc.base24 = (base >> 24) & 0xff; */
/*     tssDesc.base32 = (base >> 32) & 0xffffffff; */
/*     tssDesc.reserved = 0; */

/*     tssDesc.access = 0x01 | 0x08 | 0x10 | 0x80; */

/*     memmove(&gdtEntries[index], &tssDesc, sizeof(TssDescriptor_t)); */
/* } */


void MmInitGdt(void)
{
    gdtPtr.limit = sizeof(gdtEntries) - 1;
    gdtPtr.base = (ulong)&gdtEntries;

    MmLoadGdt();
}