/*
 * delaep64.c - Cartridge handling, Dela EP64 cart.
 *
 * Written by
 *  Michael Klein <michael.klein@puffin.lb.shuttle.de>
 *
 * This file is part of VICE, the Versatile Commodore Emulator.
 * See README for copyright notice.
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */

#include "vice.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define CARTRIDGE_INCLUDE_SLOTMAIN_API
#include "c64cartsystem.h"
#undef CARTRIDGE_INCLUDE_SLOTMAIN_API
#include "cartio.h"
#include "cartridge.h"
#include "delaep64.h"
#include "export.h"
#include "monitor.h"
#include "snapshot.h"
#include "types.h"
#include "util.h"
#include "vicii-phi1.h"
#include "crt.h"

/*
 * for cart schematics, see http://a98.shuttle.de/~michael/dela-ep64/
 */


/*
    This is an eprom cartridge. It has 1 2764 (8Kb) which  holds  the  base
    eprom with the base menu, and 2 27256 eproms of  which  8Kb  parts  are
    banked into the $8000-9FFF area.

    The bank selecting is done by writing to $DE00. The following bits  are
    used for bank decoding in $DE00:

    bit   meaning
    ---   -------
     0    eprom selection bit 2
     1    eprom selection bit 3
     2    unused
     3    unused
     4    eprom selection bit 0
     5    eprom selection bit 1
     6    unused
     7    EXROM control (1=EXROM off, 0=EXROM on)


    The following eprom select values result in the following bank selection:

    value   bank
    -----   ----
      0      0 (base)
      1      0 (base)
      2      0 (base)
      3      0 (base)
      4      1
      5      2
      6      3
      7      4
      8      5
      9      6
     10      7
     11      8
     12      0 (base)
     13      0 (base)
     14      0 (base)
     15      0 (base)
*/

/* ---------------------------------------------------------------------*/

static int currbank = 0;

static uint8_t regval = 0;

static void delaep64_io1(uint8_t value, unsigned int mode)
{
    uint8_t bank, config;

    regval = value;

    /* D7 -> EXROM */
    config = (value & 0x80) ? 2 : 0;
    cart_config_changed_slotmain(config, config, mode);

    /*
     * bank 0: 2764 (left socket)
     * bank 4-7: 1st 27256 (middle socket)
     * bank 7-11: 2nd 27256 (right socket)
     */
    bank = ((value & 0x30) >> 4) + ((value & 0x03) << 2);
    if (bank < 4 || bank > 11) {
        bank = 0;
    } else {
        bank = bank - 3;  /* turning the banks into 0-8 */
    }
    cart_romlbank_set_slotmain(bank);
    currbank = bank;
}

static uint8_t delaep64_io1_read(uint16_t addr)
{
    uint8_t value = vicii_read_phi1();

    delaep64_io1(value, CMODE_READ);

    return 0;
}

static uint8_t delaep64_io1_peek(uint16_t addr)
{
    return regval;
}

static void delaep64_io1_store(uint16_t addr, uint8_t value)
{
    delaep64_io1(value, CMODE_WRITE);
}

static int delaep64_dump(void)
{
    mon_out("Currently selected EPROM bank: %d, cart status: %s\n",
            currbank,
            (regval & 0x80) ? "Disabled" : "Enabled");
    return 0;
}

/* ---------------------------------------------------------------------*/

static io_source_t delaep64_device = {
    CARTRIDGE_NAME_DELA_EP64, /* name of the device */
    IO_DETACH_CART,           /* use cartridge ID to detach the device when involved in a read-collision */
    IO_DETACH_NO_RESOURCE,    /* does not use a resource for detach */
    0xde00, 0xdeff, 0xff,     /* range for the device, address is ignored, reg:$de00, mirrors:$de01-$deff */
    0,                        /* read is never valid */
    delaep64_io1_store,       /* store function */
    NULL,                     /* NO poke function */
    delaep64_io1_read,        /* read function */
    delaep64_io1_peek,        /* peek function */
    delaep64_dump,            /* device state information dump function */
    CARTRIDGE_DELA_EP64,      /* cartridge ID */
    IO_PRIO_NORMAL,           /* normal priority, device read needs to be checked for collisions */
    0                         /* insertion order, gets filled in by the registration function */
};

static io_source_list_t *delaep64_list_item = NULL;

static const export_resource_t export_res = {
    CARTRIDGE_NAME_DELA_EP64, 0, 1, &delaep64_device, NULL, CARTRIDGE_DELA_EP64
};

/* ---------------------------------------------------------------------*/

void delaep64_config_init(void)
{
    delaep64_io1(0, CMODE_READ);
}

void delaep64_config_setup(uint8_t *rawcart)
{
    memcpy(roml_banks, rawcart, 0x2000 * 9);
    delaep64_io1(0, CMODE_READ);
}

/* ---------------------------------------------------------------------*/
static int delaep64_common_attach(void)
{
    if (export_add(&export_res) < 0) {
        return -1;
    }
    delaep64_list_item = io_source_register(&delaep64_device);
    return 0;
}

int delaep64_bin_attach(const char *filename, uint8_t *rawcart)
{
    int size = 0x12000;

    memset(rawcart, 0xff, 0x12000);
    while (size != 0) {
        if (util_file_load(filename, rawcart, size, UTIL_FILE_LOAD_SKIP_ADDRESS) < 0) {
            size -= 0x2000;
        } else {
            return delaep64_common_attach();
        }
    }
    return -1;
}

int delaep64_crt_attach(FILE *fd, uint8_t *rawcart)
{
    int rom_size = -1;
    crt_chip_header_t chip;

    /*
     * 0x00000-0x01fff: 2764
     * 0x02000-0x09fff: 1st 27256
     * 0x0a000-0x11fff: 2nd 27256
     */
    memset(rawcart, 0xff, 0x12000);

    if (crt_read_chip_header(&chip, fd)) {
        return -1;
    }

    /* First handle the base image */
    if (chip.size != 0x2000) {
        return -1;
    }

    if (crt_read_chip(rawcart, 0, &chip, fd)) {
        return -1;
    }

    while (1) {
        if (crt_read_chip_header(&chip, fd)) {
            break;
        }

        /* check for the size of the following rom images,
           they can be of either 0x2000 or 0x8000 */
        if (chip.size != 0x2000 && chip.size != 0x8000) {
            return -1;
        }

        /* make sure all rom images are of the same size */
        if (rom_size < 0) {
            rom_size = chip.size;
        }
        if (chip.size != rom_size) {
            return -1;
        }

        /* maximum of 2 32kb or 8 8kb images allowed */
        if ((rom_size == 0x8000 && chip.bank > 2) || (rom_size == 0x2000 && chip.bank > 8)) {
            return -1;
        }

        /* put the images in the right place */
        if (crt_read_chip(rawcart, 0x2000 + ((chip.bank - 1) * rom_size), &chip, fd)) {
            return -1;
        }
    }
    return delaep64_common_attach();
}

void delaep64_detach(void)
{
    export_remove(&export_res);
    io_source_unregister(delaep64_list_item);
    delaep64_list_item = NULL;
}

/* ---------------------------------------------------------------------*/

/* CARTDELAEP64 snapshot module format:

   type  | name   | version | description
   --------------------------------------
   BYTE  | regval |   0.1   | register
   BYTE  | bank   |   0.0+  | current bank
   ARRAY | ROML   |   0.0+  | 73728 BYTES of ROML data
 */

static const char snap_module_name[] = "CARTDELAEP64";
#define SNAP_MAJOR   0
#define SNAP_MINOR   1

int delaep64_snapshot_write_module(snapshot_t *s)
{
    snapshot_module_t *m;

    m = snapshot_module_create(s, snap_module_name, SNAP_MAJOR, SNAP_MINOR);

    if (m == NULL) {
        return -1;
    }

    if (0
        || (SMW_B(m, regval) < 0)
        || (SMW_B(m, (uint8_t)currbank) < 0)
        || (SMW_BA(m, roml_banks, 0x2000 * 9) < 0)) {
        snapshot_module_close(m);
        return -1;
    }

    return snapshot_module_close(m);
}

int delaep64_snapshot_read_module(snapshot_t *s)
{
    uint8_t vmajor, vminor;
    snapshot_module_t *m;

    m = snapshot_module_open(s, snap_module_name, &vmajor, &vminor);

    if (m == NULL) {
        return -1;
    }

    /* Do not accept versions higher than current */
    if (snapshot_version_is_bigger(vmajor, vminor, SNAP_MAJOR, SNAP_MINOR)) {
        snapshot_set_error(SNAPSHOT_MODULE_HIGHER_VERSION);
        goto fail;
    }

    /* new in 0.1 */
    if (!snapshot_version_is_smaller(vmajor, vminor, 0, 1)) {
        if (SMR_B(m, &regval) < 0) {
            goto fail;
        }
    } else {
        regval = 0;
    }

    if (0
        || (SMR_B_INT(m, &currbank) < 0)
        || (SMR_BA(m, roml_banks, 0x2000 * 9) < 0)) {
        goto fail;
    }

    snapshot_module_close(m);

    return delaep64_common_attach();

fail:
    snapshot_module_close(m);
    return -1;
}
