//----------------------------------------------------------------------------//
//                                    GNU GPL OS/K                                                 //
//                                                                                                     //
//  Desc:  Interrupt 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 <kernel/base.h>
#include <kernel/cpu.h>
#include <kernel/boot.h>
#include <kernel/iomisc.h>

IdtEntry_t idt[256] = { 0 };
IdtPtr_t idtPtr;

void CpuIdtSetup(void)
{
    disablePIC();

    ushort codeSeg = (ushort)(ulong)BtLoaderInfo.codeSegment;

    // Set IDT ptr
    idtPtr.limit = (sizeof(IdtEntry_t) * 256) - 1;
    idtPtr.base = &idt;

    // Set IDT gates
    idtSet(0, (ulong)isr0, codeSeg, 0x8E);
    idtSet(1, (ulong)isr1, codeSeg, 0x8E);
    idtSet(2, (ulong)isr2, codeSeg, 0x8E);
    idtSet(3, (ulong)isr3, codeSeg, 0x8E);
    idtSet(4, (ulong)isr4, codeSeg, 0x8E);
    idtSet(5, (ulong)isr5, codeSeg, 0x8E);
    idtSet(6, (ulong)isr6, codeSeg, 0x8E);
    idtSet(7, (ulong)isr7, codeSeg, 0x8E);
    idtSet(8, (ulong)isr8, codeSeg, 0x8E);
    idtSet(9, (ulong)isr9, codeSeg, 0x8E);
    idtSet(10, (ulong)isr10, codeSeg, 0x8E);
    idtSet(11, (ulong)isr11, codeSeg, 0x8E);
    idtSet(12, (ulong)isr12, codeSeg, 0x8E);
    idtSet(13, (ulong)isr13, codeSeg, 0x8E);
    idtSet(14, (ulong)isr14, codeSeg, 0x8E);
    //idtSet(15, (ulong)isr15, codeSeg, 0x8E);  INTEL RESERVED
    idtSet(16, (ulong)isr16, codeSeg, 0x8E);
    idtSet(17, (ulong)isr17, codeSeg, 0x8E);
    idtSet(18, (ulong)isr18, codeSeg, 0x8E);
    idtSet(19, (ulong)isr19, codeSeg, 0x8E);
    idtSet(20, (ulong)isr20, codeSeg, 0x8E);
    //idtSet(21, (ulong)isr21, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(22, (ulong)isr22, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(23, (ulong)isr23, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(24, (ulong)isr24, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(25, (ulong)isr25, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(26, (ulong)isr26, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(27, (ulong)isr27, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(28, (ulong)isr28, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(29, (ulong)isr29, codeSeg, 0x8E);  INTEL RESERVED
    //idtSet(30, (ulong)isr30, codeSeg, 0x8E);  INTEL RESERVED

    // Load IDT
    DebugLog("[IdtSetup] Filled \n");
    idtInit();
    DebugLog("[IdtSetup] Initialized !\n");
}

void idtSet(uchar rank, ulong base, ushort selector, uchar flags)
{
    // Set Base Address
    idt[rank].baseLow = base & 0xFFFF;
    idt[rank].baseMid = (base >> 16) & 0xFFFF;
    idt[rank].baseHigh = (base >> 32) & 0xFFFFFFFF;

    // Set Selector
    idt[rank].selector = selector;
    idt[rank].flags = flags;

    // Set Reserved Areas to Zero
    idt[rank].reservedIst = 0;
    idt[rank].reserved = 0;
}

void disablePIC(void) {
    // Set ICW1
    IoWriteByteOnPort(0x20, 0x11);
    IoWriteByteOnPort(0xa0, 0x11);

    // Set ICW2 (IRQ base offsets)
    IoWriteByteOnPort(0x21, 0xe0);
    IoWriteByteOnPort(0xa1, 0xe8);

    // Set ICW3
    IoWriteByteOnPort(0x21, 4);
    IoWriteByteOnPort(0xa1, 2);

    // Set ICW4
    IoWriteByteOnPort(0x21, 1);
    IoWriteByteOnPort(0xa1, 1);

    // Set OCW1 (interrupt masks)
    IoWriteByteOnPort(0x21, 0xff);
    IoWriteByteOnPort(0xa1, 0xff);

    // ENABLING LOCAL APIC
    uint *val = (void*)0xfee000f0;
    *val |= (1<<8);
}

void isrHandler(Registers_t regs)
{
    DebugLog("Interrupt %d !!! \n", regs.intNo);
    return;
}