/* unofficial gameplaySP kai
 *
 * Copyright (C) 2006 Exophase <exophase@gmail.com>
 * Copyright (C) 2007 takka <takka@tfact.net>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "common.h"

const uint8_t bit_count[256] =
{
  0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
};

const uint32_t psr_masks[16] =
{
  0x00000000, 0x000000FF, 0x0000FF00, 0x0000FFFF, 0x00FF0000,
  0x00FF00FF, 0x00FFFF00, 0x00FFFFFF, 0xFF000000, 0xFF0000FF,
  0xFF00FF00, 0xFF00FFFF, 0xFFFF0000, 0xFFFF00FF, 0xFFFFFF00,
  0xFFFFFFFF
};

void set_cpu_mode(CPU_MODE_TYPE new_mode)
{
  uint32_t i;
  CPU_MODE_TYPE cpu_mode = reg[CPU_MODE];

  if(cpu_mode != new_mode)
  {
    if(new_mode == MODE_FIQ)
    {
      for(i = 8; i < 15; i++)
      {
        reg_mode[cpu_mode][i - 8] = reg[i];
      }
    }
    else
    {
      reg_mode[cpu_mode][5] = reg[REG_SP];
      reg_mode[cpu_mode][6] = reg[REG_LR];
    }

    if(cpu_mode == MODE_FIQ)
    {
      for(i = 8; i < 15; i++)
      {
        reg[i] = reg_mode[new_mode][i - 8];
      }
    }
    else
    {
      reg[REG_SP] = reg_mode[new_mode][5];
      reg[REG_LR] = reg_mode[new_mode][6];
    }

    reg[CPU_MODE] = new_mode;
  }
}

void raise_interrupt(IRQ_TYPE irq_raised)
{
  // The specific IRQ must be enabled in IE, master IRQ enable must be on,
  // and it must be on in the flags.
  io_registers[REG_IF] |= irq_raised;

  if((io_registers[REG_IME] & 0x01) && (io_registers[REG_IE] & io_registers[REG_IF]) && ((reg[REG_CPSR] & 0x80) == 0))
  {
    bios_read_protect = 0xe55ec002;

    // Interrupt handler in BIOS
    reg_mode[MODE_IRQ][6] = reg[REG_PC] + 4;
    spsr[MODE_IRQ] = reg[REG_CPSR];
    reg[REG_CPSR] = 0xD2;
    reg[REG_PC] = 0x00000018;
    bios_region_read_allow();
    set_cpu_mode(MODE_IRQ);
    reg[CPU_HALT_STATE] = CPU_ACTIVE;
    reg[CHANGED_PC_STATUS] = 1;
  }
}