/*
 * 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 1 Mbit and 2 Mbit, 8-bit and
 *          16-bit flash devices.
 *
 * Authors: Sarah Walker, <https://pcem-emulator.co.uk/>
 *          Miran Grca, <mgrca8@gmail.com>
 *
 *          Copyright 2008-2019 Sarah Walker.
 *          Copyright 2016-2019 Miran Grca.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/device.h>
#include <86box/mem.h>
#include <86box/machine.h>
#include <86box/timer.h>
#include <86box/nvr.h>
#include <86box/plat.h>
#include <86box/plat_fallthrough.h>

#define FLAG_WORD    4
#define FLAG_BXB     2
#define FLAG_INV_A16 1

enum {
    BLOCK_MAIN1,
    BLOCK_MAIN2,
    BLOCK_DATA1,
    BLOCK_DATA2,
    BLOCK_BOOT,
    BLOCKS_NUM
};

enum {
    CMD_SET_READ         = 0x00,
    CMD_READ_AUTO_SELECT = 0x80,
    CMD_READ_SIGNATURE   = 0x90,
    CMD_ERASE            = 0x20,
    CMD_ERASE_CONFIRM    = 0x20,
    CMD_ERASE_VERIFY     = 0xA0,
    CMD_PROGRAM          = 0x40,
    CMD_PROGRAM_VERIFY   = 0xC0,
    CMD_RESET            = 0xFF
};

typedef struct flash_t {
    uint8_t command;
    uint8_t is_amd;
    uint8_t pad;
    uint8_t pad0;
    uint8_t *array;

    mem_mapping_t mapping;
    mem_mapping_t mapping_h[2];
} flash_t;

static char flash_path[1024];

static uint8_t
flash_read(uint32_t addr, void *priv)
{
    const flash_t *dev = (flash_t *) priv;
    uint8_t        ret = 0xff;

    addr &= biosmask;

    switch (dev->command) {
        case CMD_ERASE_VERIFY:
        case CMD_PROGRAM_VERIFY:
        case CMD_RESET:
        case CMD_SET_READ:
            ret = dev->array[addr];
            break;

        case CMD_READ_AUTO_SELECT:
            if (!dev->is_amd)
                break;
            fallthrough;
        case CMD_READ_SIGNATURE:
            if (dev->is_amd) {
                if (addr == 0x00000)
                    ret = 0x01; /* AMD */
                else if (addr == 0x00001)
                    ret = 0xa7; /* Am28F010 */
            } else {
                if (addr == 0x00000)
                    ret = 0x31; /* CATALYST */
                else if (addr == 0x00001)
                    ret = 0xb4; /* 28F010 */
            }
            break;

        default:
            break;
    }

    return ret;
}

static uint16_t
flash_readw(uint32_t addr, void *priv)
{
    flash_t        *dev = (flash_t *) priv;
    const uint16_t *q;

    addr &= biosmask;

    q = (uint16_t *) &(dev->array[addr]);

    return *q;
}

static uint32_t
flash_readl(uint32_t addr, void *priv)
{
    flash_t        *dev = (flash_t *) priv;
    const uint32_t *q;

    addr &= biosmask;

    q = (uint32_t *) &(dev->array[addr]);

    return *q;
}

static void
flash_write(uint32_t addr, uint8_t val, void *priv)
{
    flash_t *dev = (flash_t *) priv;

    addr &= biosmask;

    switch (dev->command) {
        case CMD_ERASE:
            if (val == CMD_ERASE_CONFIRM)
                memset(dev->array, 0xff, biosmask + 1);
            break;

        case CMD_PROGRAM:
            dev->array[addr] = val;
            break;

        default:
            dev->command = val;
            break;
    }
}

static void
flash_writew(UNUSED(uint32_t addr), UNUSED(uint16_t val), UNUSED(void *priv))
{
    //
}

static void
flash_writel(UNUSED(uint32_t addr), UNUSED(uint32_t val), UNUSED(void *priv))
{
    //
}

static void
catalyst_flash_add_mappings(flash_t *dev)
{
    memcpy(dev->array, rom, biosmask + 1);

    mem_mapping_add(&dev->mapping, 0xe0000, 0x20000,
                    flash_read, flash_readw, flash_readl,
                    flash_write, flash_writew, flash_writel,
                    dev->array, MEM_MAPPING_EXTERNAL | MEM_MAPPING_ROM | MEM_MAPPING_ROMCS, (void *) dev);

    mem_mapping_add(&(dev->mapping_h[0]), 0xfffc0000, 0x20000,
                    flash_read, flash_readw, flash_readl,
                    flash_write, flash_writew, flash_writel,
                    dev->array, MEM_MAPPING_EXTERNAL | MEM_MAPPING_ROM | MEM_MAPPING_ROMCS, (void *) dev);
    mem_mapping_add(&(dev->mapping_h[1]), 0xfffe0000, 0x20000,
                    flash_read, flash_readw, flash_readl,
                    flash_write, flash_writew, flash_writel,
                    dev->array, MEM_MAPPING_EXTERNAL | MEM_MAPPING_ROM | MEM_MAPPING_ROMCS, (void *) dev);
}

static void
catalyst_flash_reset(void *priv)
{
    flash_t *dev = (flash_t *) priv;

    dev->command = CMD_RESET;
}

static void *
catalyst_flash_init(UNUSED(const device_t *info))
{
    FILE    *fp;
    flash_t *dev;

    dev = calloc(1, sizeof(flash_t));

    sprintf(flash_path, "%s.bin", machine_get_nvr_name_ex(machine));

    mem_mapping_disable(&bios_mapping);
    mem_mapping_disable(&bios_high_mapping);

    dev->array = (uint8_t *) malloc(0x20000);
    memset(dev->array, 0xff, 0x20000);

    catalyst_flash_add_mappings(dev);

    dev->command = CMD_RESET;
    dev->is_amd  = info->local;

    fp = nvr_fopen(flash_path, "rb");
    if (fp) {
        (void) !fread(dev->array, 0x20000, 1, fp);
        fclose(fp);
    }

    return dev;
}

static void
catalyst_flash_close(void *priv)
{
    FILE    *fp;
    flash_t *dev = (flash_t *) priv;

    fp = nvr_fopen(flash_path, "wb");
    fwrite(dev->array, 0x20000, 1, fp);
    fclose(fp);

    free(dev->array);
    dev->array = NULL;

    free(dev);
}

const device_t catalyst_flash_device = {
    .name          = "Catalyst 28F010-D Flash BIOS",
    .internal_name = "catalyst_flash",
    .flags         = DEVICE_PCI,
    .local         = 0,
    .init          = catalyst_flash_init,
    .close         = catalyst_flash_close,
    .reset         = catalyst_flash_reset,
    .available     = NULL,
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};

const device_t amd_am28f010_flash_device = {
    .name          = "AMD Am28F010-D Flash BIOS",
    .internal_name = "amd_am28f010_flash",
    .flags         = DEVICE_PCI,
    .local         = 1,
    .init          = catalyst_flash_init,
    .close         = catalyst_flash_close,
    .reset         = catalyst_flash_reset,
    .available     = NULL,
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};
