/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		Implementation of the Intel 440FX PCISet chip.
 *
 * Version:	@(#)i440fx.c	1.0.1	2017/06/17
 *
 * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
 *		Miran Grca, <mgrca8@gmail.com>
 *		Copyright 2008-2017 Sarah Walker.
 *		Copyright 2016-2017 Miran Grca.
 */
#include <string.h>
#include "ibm.h"
#include "cpu/cpu.h"
#include "io.h"
#include "mem.h"
#include "pci.h"
#include "device.h"
#include "model.h"


static uint8_t card_i440fx[256];


static void i440fx_map(uint32_t addr, uint32_t size, int state)
{
        switch (state & 3)
        {
                case 0:
                mem_set_mem_state(addr, size, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
                break;
                case 1:
                mem_set_mem_state(addr, size, MEM_READ_INTERNAL | MEM_WRITE_EXTERNAL);
                break;
                case 2:
                mem_set_mem_state(addr, size, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
                break;
                case 3:
                mem_set_mem_state(addr, size, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
                break;
        }
        flushmmucache_nopc();        
}


static void i440fx_write(int func, int addr, uint8_t val, void *priv)
{
        if (func)
           return;
           
        if ((addr >= 0x10) && (addr < 0x4f))
                return;
                
        switch (addr)
        {
                case 0x00: case 0x01: case 0x02: case 0x03:
                case 0x08: case 0x09: case 0x0a: case 0x0b:
                case 0x0c: case 0x0e:
                return;
                
                case 0x04: /*Command register*/
                val &= 0x02;
                val |= 0x04;
                break;
                case 0x05:
                val = 0;
                break;
                
                case 0x06: /*Status*/
                val = 0;
                break;
                case 0x07:
                val &= 0x80;
                val |= 0x02;
                break;
                
                case 0x59: /*PAM0*/
                if ((card_i440fx[0x59] ^ val) & 0xf0)
                {
                        i440fx_map(0xf0000, 0x10000, val >> 4);
                        shadowbios = (val & 0x10);
                }
                break;
                case 0x5a: /*PAM1*/
                if ((card_i440fx[0x5a] ^ val) & 0x0f)
                        i440fx_map(0xc0000, 0x04000, val & 0xf);
                if ((card_i440fx[0x5a] ^ val) & 0xf0)
                        i440fx_map(0xc4000, 0x04000, val >> 4);
                break;
                case 0x5b: /*PAM2*/
                if ((card_i440fx[0x5b] ^ val) & 0x0f)
                        i440fx_map(0xc8000, 0x04000, val & 0xf);
                if ((card_i440fx[0x5b] ^ val) & 0xf0)
                        i440fx_map(0xcc000, 0x04000, val >> 4);
                break;
                case 0x5c: /*PAM3*/
                if ((card_i440fx[0x5c] ^ val) & 0x0f)
                        i440fx_map(0xd0000, 0x04000, val & 0xf);
                if ((card_i440fx[0x5c] ^ val) & 0xf0)
                        i440fx_map(0xd4000, 0x04000, val >> 4);
                break;
                case 0x5d: /*PAM4*/
                if ((card_i440fx[0x5d] ^ val) & 0x0f)
                        i440fx_map(0xd8000, 0x04000, val & 0xf);
                if ((card_i440fx[0x5d] ^ val) & 0xf0)
                        i440fx_map(0xdc000, 0x04000, val >> 4);
                break;
                case 0x5e: /*PAM5*/
                if ((card_i440fx[0x5e] ^ val) & 0x0f)
                        i440fx_map(0xe0000, 0x04000, val & 0xf);
                if ((card_i440fx[0x5e] ^ val) & 0xf0)
                        i440fx_map(0xe4000, 0x04000, val >> 4);
                break;
                case 0x5f: /*PAM6*/
                if ((card_i440fx[0x5f] ^ val) & 0x0f)
                        i440fx_map(0xe8000, 0x04000, val & 0xf);
                if ((card_i440fx[0x5f] ^ val) & 0xf0)
                        i440fx_map(0xec000, 0x04000, val >> 4);
                break;
        }
                
        card_i440fx[addr] = val;
}


static uint8_t i440fx_read(int func, int addr, void *priv)
{
        if (func)
           return 0xff;

        return card_i440fx[addr];
}
 

static void i440fx_reset(void)
{
        memset(card_i440fx, 0, 256);
        card_i440fx[0x00] = 0x86; card_i440fx[0x01] = 0x80; /*Intel*/
        card_i440fx[0x02] = 0x37; card_i440fx[0x03] = 0x12; /*82441FX*/
        card_i440fx[0x04] = 0x03; card_i440fx[0x05] = 0x01;
        card_i440fx[0x06] = 0x80; card_i440fx[0x07] = 0x00;
        card_i440fx[0x08] = 0x02; /*A0 stepping*/
        card_i440fx[0x09] = 0x00; card_i440fx[0x0a] = 0x00; card_i440fx[0x0b] = 0x06;
	card_i440fx[0x0d] = 0x00;
	card_i440fx[0x0f] = 0x00;
	card_i440fx[0x2c] = 0xf4;
	card_i440fx[0x2d] = 0x1a;
	card_i440fx[0x2e] = 0x00;
	card_i440fx[0x2f] = 0x11;
	card_i440fx[0x50] = 0x00;
	card_i440fx[0x51] = 0x01;
	card_i440fx[0x52] = card_i440fx[0x54] = card_i440fx[0x55] = card_i440fx[0x56] = 0x00;
        card_i440fx[0x53] = 0x80;
        card_i440fx[0x57] = 0x01;
        card_i440fx[0x58] = 0x10;
	card_i440fx[0x5a] = card_i440fx[0x5b] = card_i440fx[0x5c] = card_i440fx[0x5d] = card_i440fx[0x5e] = 0x11;
	card_i440fx[0x5f] = 0x31;
        card_i440fx[0x72] = 0x02;
}
    

static void i440fx_pci_reset(void)
{
	i440fx_write(0, 0x59, 0x00, NULL);
}


void i440fx_init(void)
{
        pci_add_specific(0, i440fx_read, i440fx_write, NULL);
        
	i440fx_reset();

	pci_reset_handler.pci_master_reset = i440fx_pci_reset;
}