emulator.c

// SPDX-License-Identifier: MIT

#include "m68k.h"
#include "emulator.h"
#include "platforms/platforms.h"
#include "input/input.h"

#include "platforms/amiga/Gayle.h"
#include "platforms/amiga/amiga-registers.h"
#include "platforms/amiga/rtg/rtg.h"
#include "platforms/amiga/hunk-reloc.h"
#include "platforms/amiga/piscsi/piscsi.h"
#include "platforms/amiga/piscsi/piscsi-enums.h"
#include "platforms/amiga/net/pi-net.h"
#include "platforms/amiga/net/pi-net-enums.h"
#include "gpio/ps_protocol.h"

#include <assert.h>
#include <dirent.h>
#include <endian.h>
#include <fcntl.h>
#include <poll.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#define KEY_POLL_INTERVAL_MSEC 5000

unsigned char read_ranges;
unsigned int read_addr[8];
unsigned int read_upper[8];
unsigned char *read_data[8];
unsigned char write_ranges;
unsigned int write_addr[8];
unsigned int write_upper[8];
unsigned char *write_data[8];

int kb_hook_enabled = 0;
int mouse_hook_enabled = 0;
int cpu_emulation_running = 1;

uint8_t mouse_dx = 0, mouse_dy = 0;
uint8_t mouse_buttons = 0;
uint8_t mouse_extra = 0;

extern uint8_t gayle_int;
extern uint8_t gayle_ide_enabled;
extern uint8_t gayle_emulation_enabled;
extern uint8_t gayle_a4k_int;
extern volatile unsigned int *gpio;
extern volatile uint16_t srdata;
extern uint8_t realtime_graphics_debug;
extern uint8_t rtg_on;
uint8_t realtime_disassembly, int2_enabled = 0;
uint32_t do_disasm = 0, old_level;
uint32_t last_irq = 8, last_last_irq = 8;

uint8_t end_signal = 0;

char disasm_buf[4096];

#define KICKBASE 0xF80000
#define KICKSIZE 0x7FFFF

int mem_fd, mouse_fd = -1, keyboard_fd = -1;
int mem_fd_gpclk;
int irq;
int gayleirq;

#define MUSASHI_HAX

#ifdef MUSASHI_HAX
#include "m68kcpu.h"
extern m68ki_cpu_core m68ki_cpu;
extern int m68ki_initial_cycles;
extern int m68ki_remaining_cycles;

#define M68K_SET_IRQ(i) old_level = CPU_INT_LEVEL; \
	CPU_INT_LEVEL = (i << 8); \
	if(old_level != 0x0700 && CPU_INT_LEVEL == 0x0700) \
		m68ki_cpu.nmi_pending = TRUE;
#define M68K_END_TIMESLICE 	m68ki_initial_cycles = GET_CYCLES(); \
	SET_CYCLES(0);
#else
#define M68K_SET_IRQ m68k_set_irq
#define M68K_END_TIMESLICE m68k_end_timeslice()
#endif

#define NOP asm("nop"); asm("nop"); asm("nop"); asm("nop");

#define DEBUG_EMULATOR
#ifdef DEBUG_EMULATOR
#define DEBUG printf
#else
#define DEBUG(...)
#endif

// Configurable emulator options
unsigned int cpu_type = M68K_CPU_TYPE_68000;
unsigned int loop_cycles = 300, irq_status = 0;
struct emulator_config *cfg = NULL;
char keyboard_file[256] = "/dev/input/event1";

uint64_t trig_irq = 0, serv_irq = 0;
uint16_t irq_delay = 0;
unsigned int amiga_reset=0, amiga_reset_last=0;
unsigned int do_reset=0;

void *ipl_task(void *args) {
  printf("IPL thread running\n");
  uint16_t old_irq = 0;
  uint32_t value;

  while (1) {
    value = *(gpio + 13);

    if (!(value & (1 << PIN_IPL_ZERO))) {
      irq = 1;
      old_irq = irq_delay;
      //NOP
      M68K_END_TIMESLICE;
      NOP
      //usleep(0);
    }
    else {
      if (irq) {
        if (old_irq) {
          old_irq--;
        }
        else {
          irq = 0;
        }
        M68K_END_TIMESLICE;
        NOP
        //usleep(0);
      }
    }
    if(do_reset==0)
    {
      amiga_reset=(value & (1 << PIN_RESET));
      if(amiga_reset!=amiga_reset_last)
      {
        amiga_reset_last=amiga_reset;
        if(amiga_reset==0)
        {
          printf("Amiga Reset is down...\n");
          do_reset=1;
          M68K_END_TIMESLICE;
        }
        else
        {
          printf("Amiga Reset is up...\n");
        }
      }
    }

    /*if (gayle_ide_enabled) {
      if (((gayle_int & 0x80) || gayle_a4k_int) && (get_ide(0)->drive[0].intrq || get_ide(0)->drive[1].intrq)) {
        //get_ide(0)->drive[0].intrq = 0;
        gayleirq = 1;
        M68K_END_TIMESLICE;
      }
      else
        gayleirq = 0;
    }*/
    //usleep(0);
    //NOP NOP
    NOP NOP NOP NOP NOP NOP NOP NOP
    //NOP NOP NOP NOP NOP NOP NOP NOP
    //NOP NOP NOP NOP NOP NOP NOP NOP
    /*NOP NOP NOP NOP NOP NOP NOP NOP
    NOP NOP NOP NOP NOP NOP NOP NOP
    NOP NOP NOP NOP NOP NOP NOP NOP*/
  }
  return args;
}

void *cpu_task() {
  m68k_pulse_reset();

cpu_loop:
  if (mouse_hook_enabled) {
    get_mouse_status(&mouse_dx, &mouse_dy, &mouse_buttons, &mouse_extra);
  }

  if (realtime_disassembly && (do_disasm || cpu_emulation_running)) {
    m68k_disassemble(disasm_buf, m68k_get_reg(NULL, M68K_REG_PC), cpu_type);
    printf("REGA: 0:$%.8X 1:$%.8X 2:$%.8X 3:$%.8X 4:$%.8X 5:$%.8X 6:$%.8X 7:$%.8X\n", m68k_get_reg(NULL, M68K_REG_A0), m68k_get_reg(NULL, M68K_REG_A1), m68k_get_reg(NULL, M68K_REG_A2), m68k_get_reg(NULL, M68K_REG_A3), \
            m68k_get_reg(NULL, M68K_REG_A4), m68k_get_reg(NULL, M68K_REG_A5), m68k_get_reg(NULL, M68K_REG_A6), m68k_get_reg(NULL, M68K_REG_A7));
    printf("REGD: 0:$%.8X 1:$%.8X 2:$%.8X 3:$%.8X 4:$%.8X 5:$%.8X 6:$%.8X 7:$%.8X\n", m68k_get_reg(NULL, M68K_REG_D0), m68k_get_reg(NULL, M68K_REG_D1), m68k_get_reg(NULL, M68K_REG_D2), m68k_get_reg(NULL, M68K_REG_D3), \
            m68k_get_reg(NULL, M68K_REG_D4), m68k_get_reg(NULL, M68K_REG_D5), m68k_get_reg(NULL, M68K_REG_D6), m68k_get_reg(NULL, M68K_REG_D7));
    printf("%.8X (%.8X)]] %s\n", m68k_get_reg(NULL, M68K_REG_PC), (m68k_get_reg(NULL, M68K_REG_PC) & 0xFFFFFF), disasm_buf);
    if (do_disasm)
      do_disasm--;
    m68k_execute(1);
  }
  else {
    if (cpu_emulation_running)
      m68k_execute(loop_cycles);
  }

  if (irq) {
    while (irq) {
      last_irq = ((read_reg() & 0xe000) >> 13);
      if (last_irq != last_last_irq) {
        last_last_irq = last_irq;
        M68K_SET_IRQ(last_irq);
      }
      m68k_execute(5);
    }
    if (gayleirq && int2_enabled) {
      write16(0xdff09c, 0x8000 | (1 << 3) && last_irq != 2);
      last_last_irq = last_irq;
      last_irq = 2;
      M68K_SET_IRQ(2);
    }
    M68K_SET_IRQ(0);
    last_last_irq = 0;
    m68k_execute(5);
  }
  /*else {
    if (last_irq != 0) {
      M68K_SET_IRQ(0);
      last_last_irq = last_irq;
      last_irq = 0;
    }
  }*/
  if (do_reset) {
    cpu_pulse_reset();
    do_reset=0;
    usleep(1000000); // 1sec
    rtg_on=0;
//    while(amiga_reset==0);
//    printf("CPU emulation reset.\n");
  }

  if (mouse_hook_enabled && (mouse_extra != 0x00)) {
    // mouse wheel events have occurred; unlike l/m/r buttons, these are queued as keypresses, so add to end of buffer
    switch (mouse_extra) {
      case 0xff:
        // wheel up
        queue_keypress(0xfe, KEYPRESS_PRESS, PLATFORM_AMIGA);
        break;
      case 0x01:
        // wheel down
        queue_keypress(0xff, KEYPRESS_PRESS, PLATFORM_AMIGA);
        break;
    }

    // dampen the scroll wheel until next while loop iteration
    mouse_extra = 0x00;
  }

  if (end_signal)
	  goto stop_cpu_emulation;

  goto cpu_loop;

stop_cpu_emulation:
  printf("[CPU] End of CPU thread\n");
  return (void *)NULL;
}

void *keyboard_task() {
  struct pollfd kbdpoll[1];
  int kpollrc;
  char c = 0, c_code = 0, c_type = 0;
  char grab_message[] = "[KBD] Grabbing keyboard from input layer\n",
       ungrab_message[] = "[KBD] Ungrabbing keyboard\n";

  printf("[KBD] Keyboard thread started\n");

  // because we permit the keyboard to be grabbed on startup, quickly check if we need to grab it
  if (kb_hook_enabled && cfg->keyboard_grab) {
    printf(grab_message);
    grab_device(keyboard_fd);
  }

  kbdpoll[0].fd = keyboard_fd;
  kbdpoll[0].events = POLLIN;

key_loop:
  kpollrc = poll(kbdpoll, 1, KEY_POLL_INTERVAL_MSEC);
  if ((kpollrc > 0) && (kbdpoll[0].revents & POLLHUP)) {
    // in the event that a keyboard is unplugged, keyboard_task will whiz up to 100% utilisation
    // this is undesired, so if the keyboard HUPs, end the thread without ending the emulation
    printf("[KBD] Keyboard node returned HUP (unplugged?)\n");
    goto key_end;
  }

  // if kpollrc > 0 then it contains number of events to pull, also check if POLLIN is set in revents
  if ((kpollrc <= 0) || !(kbdpoll[0].revents & POLLIN)) {
    goto key_loop;
  }

  while (get_key_char(&c, &c_code, &c_type)) {
    if (c && c == cfg->keyboard_toggle_key && !kb_hook_enabled) {
      kb_hook_enabled = 1;
      printf("[KBD] Keyboard hook enabled.\n");
      if (cfg->keyboard_grab) {
        grab_device(keyboard_fd);
        printf(grab_message);
      }
    } else if (kb_hook_enabled) {
      if (c == 0x1B && c_type) {
        kb_hook_enabled = 0;
        printf("[KBD] Keyboard hook disabled.\n");
        if (cfg->keyboard_grab) {
          release_device(keyboard_fd);
          printf(ungrab_message);
        }
      } else {
        if (queue_keypress(c_code, c_type, cfg->platform->id) && int2_enabled && last_irq != 2) {
          //last_irq = 0;
          //M68K_SET_IRQ(2);
        }
      }
    }

    // pause pressed; trigger nmi (int level 7)
    if (c == 0x01 && c_type) {
      printf("[INT] Sending NMI\n");
      M68K_SET_IRQ(7);
    }

    if (!kb_hook_enabled && c_type) {
      if (c && c == cfg->mouse_toggle_key) {
        mouse_hook_enabled ^= 1;
        printf("Mouse hook %s.\n", mouse_hook_enabled ? "enabled" : "disabled");
        mouse_dx = mouse_dy = mouse_buttons = mouse_extra = 0;
      }
      if (c == 'r') {
        cpu_emulation_running ^= 1;
        printf("CPU emulation is now %s\n", cpu_emulation_running ? "running" : "stopped");
      }
      if (c == 'g') {
        realtime_graphics_debug ^= 1;
        printf("Real time graphics debug is now %s\n", realtime_graphics_debug ? "on" : "off");
      }
      if (c == 'R') {
        cpu_pulse_reset();
        //m68k_pulse_reset();
        printf("CPU emulation reset.\n");
      }
      if (c == 'q') {
        printf("Quitting and exiting emulator.\n");
	      end_signal = 1;
        goto key_end;
      }
      if (c == 'd') {
        realtime_disassembly ^= 1;
        do_disasm = 1;
        printf("Real time disassembly is now %s\n", realtime_disassembly ? "on" : "off");
      }
      if (c == 'D') {
        int r = get_mapped_item_by_address(cfg, 0x08000000);
        if (r != -1) {
          printf("Dumping first 16MB of mapped range %d.\n", r);
          FILE *dmp = fopen("./memdmp.bin", "wb+");
          fwrite(cfg->map_data[r], 16 * SIZE_MEGA, 1, dmp);
          fclose(dmp);
        }
      }
      if (c == 's' && realtime_disassembly) {
        do_disasm = 1;
      }
      if (c == 'S' && realtime_disassembly) {
        do_disasm = 128;
      }
    }
  }

  goto key_loop;

key_end:
  printf("[KBD] Keyboard thread ending\n");
  if (cfg->keyboard_grab) {
    printf(ungrab_message);
    release_device(keyboard_fd);
  }
  return (void*)NULL;
}

void stop_cpu_emulation(uint8_t disasm_cur) {
  M68K_END_TIMESLICE;
  if (disasm_cur) {
    m68k_disassemble(disasm_buf, m68k_get_reg(NULL, M68K_REG_PC), cpu_type);
    printf("REGA: 0:$%.8X 1:$%.8X 2:$%.8X 3:$%.8X 4:$%.8X 5:$%.8X 6:$%.8X 7:$%.8X\n", m68k_get_reg(NULL, M68K_REG_A0), m68k_get_reg(NULL, M68K_REG_A1), m68k_get_reg(NULL, M68K_REG_A2), m68k_get_reg(NULL, M68K_REG_A3), \
            m68k_get_reg(NULL, M68K_REG_A4), m68k_get_reg(NULL, M68K_REG_A5), m68k_get_reg(NULL, M68K_REG_A6), m68k_get_reg(NULL, M68K_REG_A7));
    printf("REGD: 0:$%.8X 1:$%.8X 2:$%.8X 3:$%.8X 4:$%.8X 5:$%.8X 6:$%.8X 7:$%.8X\n", m68k_get_reg(NULL, M68K_REG_D0), m68k_get_reg(NULL, M68K_REG_D1), m68k_get_reg(NULL, M68K_REG_D2), m68k_get_reg(NULL, M68K_REG_D3), \
            m68k_get_reg(NULL, M68K_REG_D4), m68k_get_reg(NULL, M68K_REG_D5), m68k_get_reg(NULL, M68K_REG_D6), m68k_get_reg(NULL, M68K_REG_D7));
    printf("%.8X (%.8X)]] %s\n", m68k_get_reg(NULL, M68K_REG_PC), (m68k_get_reg(NULL, M68K_REG_PC) & 0xFFFFFF), disasm_buf);
    realtime_disassembly = 1;
  }

  cpu_emulation_running = 0;
  do_disasm = 0;
}

unsigned int ovl;
static volatile unsigned char maprom;

void sigint_handler(int sig_num) {
  //if (sig_num) { }
  //cpu_emulation_running = 0;

  //return;
  printf("Received sigint %d, exiting.\n", sig_num);
  if (mouse_fd != -1)
    close(mouse_fd);
  if (mem_fd)
    close(mem_fd);

  if (cfg->platform->shutdown) {
    cfg->platform->shutdown(cfg);
  }

  printf("IRQs triggered: %lld\n", trig_irq);
  printf("IRQs serviced: %lld\n", serv_irq);

  exit(0);
}

int main(int argc, char *argv[]) {
  int g;
  //const struct sched_param priority = {99};

  // Some command line switch stuffles
  for (g = 1; g < argc; g++) {
    if (strcmp(argv[g], "--cpu_type") == 0 || strcmp(argv[g], "--cpu") == 0) {
      if (g + 1 >= argc) {
        printf("%s switch found, but no CPU type specified.\n", argv[g]);
      } else {
        g++;
        cpu_type = get_m68k_cpu_type(argv[g]);
      }
    }
    else if (strcmp(argv[g], "--config-file") == 0 || strcmp(argv[g], "--config") == 0) {
      if (g + 1 >= argc) {
        printf("%s switch found, but no config filename specified.\n", argv[g]);
      } else {
        g++;
        cfg = load_config_file(argv[g]);
      }
    }
    else if (strcmp(argv[g], "--keyboard-file") == 0 || strcmp(argv[g], "--kbfile") == 0) {
      if (g + 1 >= argc) {
        printf("%s switch found, but no keyboard device path specified.\n", argv[g]);
      } else {
        g++;
        strcpy(keyboard_file, argv[g]);
      }
    }
  }

  if (!cfg) {
    printf("No config file specified. Trying to load default.cfg...\n");
    cfg = load_config_file("default.cfg");
    if (!cfg) {
      printf("Couldn't load default.cfg, empty emulator config will be used.\n");
      cfg = (struct emulator_config *)calloc(1, sizeof(struct emulator_config));
      if (!cfg) {
        printf("Failed to allocate memory for emulator config!\n");
        return 1;
      }
      memset(cfg, 0x00, sizeof(struct emulator_config));
    }
  }

  if (cfg) {
    if (cfg->cpu_type) cpu_type = cfg->cpu_type;
    if (cfg->loop_cycles) loop_cycles = cfg->loop_cycles;

    if (!cfg->platform)
      cfg->platform = make_platform_config("none", "generic");
    cfg->platform->platform_initial_setup(cfg);
  }

  if (cfg->mouse_enabled) {
    mouse_fd = open(cfg->mouse_file, O_RDWR | O_NONBLOCK);
    if (mouse_fd == -1) {
      printf("Failed to open %s, can't enable mouse hook.\n", cfg->mouse_file);
      cfg->mouse_enabled = 0;
    } else {
      /**
       * *-*-*-* magic numbers! *-*-*-*
       * great, so waaaay back in the history of the pc, the ps/2 protocol set the standard for mice
       * and in the process, the mouse sample rate was defined as a way of putting mice into vendor-specific modes.
       * as the ancient gpm command explains, almost everything except incredibly old mice talk the IntelliMouse
       * protocol, which reports four bytes. by default, every mouse starts in 3-byte mode (don't report wheel or
       * additional buttons) until imps2 magic is sent. so, command $f3 is "set sample rate", followed by a byte.
       */
      uint8_t mouse_init[] = { 0xf4, 0xf3, 0x64 }; // enable, then set sample rate 100
      uint8_t imps2_init[] = { 0xf3, 0xc8, 0xf3, 0x64, 0xf3, 0x50 }; // magic sequence; set sample 200, 100, 80
      if (write(mouse_fd, mouse_init, sizeof(mouse_init)) != -1) {
        if (write(mouse_fd, imps2_init, sizeof(imps2_init)) == -1)
          printf("[MOUSE] Couldn't enable scroll wheel events; is this mouse from the 1980s?\n");
      } else
        printf("[MOUSE] Mouse didn't respond to normal PS/2 init; have you plugged a brick in by mistake?\n");
    }
  }

  if (cfg->keyboard_file)
    keyboard_fd = open(cfg->keyboard_file, O_RDONLY | O_NONBLOCK);
  else
    keyboard_fd = open(keyboard_file, O_RDONLY | O_NONBLOCK);

  if (keyboard_fd == -1) {
    printf("Failed to open keyboard event source.\n");
  }

  if (cfg->mouse_autoconnect)
    mouse_hook_enabled = 1;

  if (cfg->keyboard_autoconnect)
    kb_hook_enabled = 1;

  InitGayle();

  signal(SIGINT, sigint_handler);
  /*setup_io();

  //goto skip_everything;

  // Enable 200MHz CLK output on GPIO4, adjust divider and pll source depending
  // on pi model
  printf("Enable 200MHz GPCLK0 on GPIO4\n");
  gpio_enable_200mhz();

  // reset cpld statemachine first

  write_reg(0x01);
  usleep(100);
  usleep(1500);
  write_reg(0x00);
  usleep(100);

  // reset amiga and statemachine
  skip_everything:;

  usleep(1500);

  m68k_init();
  printf("Setting CPU type to %d.\n", cpu_type);
  m68k_set_cpu_type(cpu_type);
  cpu_pulse_reset();

  if (maprom == 1) {
    m68k_set_reg(M68K_REG_PC, 0xF80002);
  } else {
    m68k_set_reg(M68K_REG_PC, 0x0);
  }*/
  ps_setup_protocol();
  ps_reset_state_machine();
  ps_pulse_reset();

  usleep(1500);
  m68k_init();
  printf("Setting CPU type to %d.\n", cpu_type);
  m68k_set_cpu_type(cpu_type);
  cpu_pulse_reset();

  pthread_t ipl_tid, cpu_tid, kbd_tid;
  int err;
  err = pthread_create(&ipl_tid, NULL, &ipl_task, NULL);
  if (err != 0)
    printf("[ERROR] Cannot create IPL thread: [%s]", strerror(err));
  else {
    pthread_setname_np(ipl_tid, "pistorm: ipl");
    printf("IPL thread created successfully\n");
  }

  // create keyboard task
  err = pthread_create(&kbd_tid, NULL, &keyboard_task, NULL);
  if (err != 0)
    printf("[ERROR] Cannot create keyboard thread: [%s]", strerror(err));
  else {
    pthread_setname_np(kbd_tid, "pistorm: kbd");
    printf("[MAIN] Keyboard thread created successfully\n");
  }

  // create cpu task
  err = pthread_create(&cpu_tid, NULL, &cpu_task, NULL);
  if (err != 0)
    printf("[ERROR] Cannot create CPU thread: [%s]", strerror(err));
  else {
    pthread_setname_np(cpu_tid, "pistorm: cpu");
    printf("[MAIN] CPU thread created successfully\n");
  }

  // wait for cpu task to end before closing up and finishing
  pthread_join(cpu_tid, NULL);
  printf("[MAIN] All threads appear to have concluded; ending process\n");

  if (mouse_fd != -1)
    close(mouse_fd);
  if (mem_fd)
    close(mem_fd);

  return 0;
}

void cpu_pulse_reset(void) {
  ps_pulse_reset();
  //write_reg(0x00);
  // printf("Status Reg%x\n",read_reg());
  //usleep(100000);
  //write_reg(0x02);
  // printf("Status Reg%x\n",read_reg());
  if (cfg->platform->handle_reset)
    cfg->platform->handle_reset(cfg);

  //m68k_write_memory_16(INTENA, 0x7FFF);
  ovl = 1;
  m68k_write_memory_8(0xbfe201, 0x0001);  // AMIGA OVL
  m68k_write_memory_8(0xbfe001, 0x0001);  // AMIGA OVL high (ROM@0x0)

  m68k_pulse_reset();
}

int cpu_irq_ack(int level) {
  printf("cpu irq ack\n");
  return level;
}

static unsigned int target = 0;
static uint8_t send_keypress = 0;

uint8_t cdtv_dmac_reg_idx_read();
void cdtv_dmac_reg_idx_write(uint8_t value);
uint32_t cdtv_dmac_read(uint32_t address, uint8_t type);
void cdtv_dmac_write(uint32_t address, uint32_t value, uint8_t type);

#define PLATFORM_CHECK_READ(a) \
  if (address >= cfg->custom_low && address < cfg->custom_high) { \
    unsigned int target = 0; \
    switch(cfg->platform->id) { \
      case PLATFORM_AMIGA: { \
        if (address >= PISCSI_OFFSET && address < PISCSI_UPPER) { \
          return handle_piscsi_read(address, a); \
        } \
        if (address >= PINET_OFFSET && address < PINET_UPPER) { \
          return handle_pinet_read(address, a); \
        } \
        if (address >= PIGFX_RTG_BASE && address < PIGFX_UPPER) { \
          return rtg_read((address & 0x0FFFFFFF), a); \
        } \
        if (custom_read_amiga(cfg, address, &target, a) != -1) { \
          return target; \
        } \
        break; \
      } \
      default: \
        break; \
    } \
  } \
  if (ovl || (address >= cfg->mapped_low && address < cfg->mapped_high)) { \
    if (handle_mapped_read(cfg, address, &target, a) != -1) \
      return target; \
  }

unsigned int m68k_read_memory_8(unsigned int address) {
  PLATFORM_CHECK_READ(OP_TYPE_BYTE);

  /*if (address >= 0xE90000 && address < 0xF00000) {
    printf("BYTE read from DMAC @%.8X:", address);
    uint32_t v = cdtv_dmac_read(address & 0xFFFF, OP_TYPE_BYTE);
    printf("%.2X\n", v);
    M68K_END_TIMESLICE;
    cpu_emulation_running = 0;
    return v;
  }*/

  /*if (m68k_get_reg(NULL, M68K_REG_PC) >= 0x080032F0 && m68k_get_reg(NULL, M68K_REG_PC) <= 0x080032F0 + 0x4000) {
    stop_cpu_emulation(1);
  }*/


  if (address & 0xFF000000)
    return 0;

  unsigned char result = (unsigned int)read8((uint32_t)address);

  if (mouse_hook_enabled) {
    if (address == CIAAPRA) {
      if (mouse_buttons & 0x01) {
        //mouse_buttons -= 1;
        return (unsigned int)(result ^ 0x40);
      }

      return (unsigned int)result;
    }
  }

  if (kb_hook_enabled) {
    if (address == CIAAICR) {
      if (get_num_kb_queued() && (!send_keypress || send_keypress == 1)) {
        result |= 0x08;
        if (!send_keypress)
          send_keypress = 1;
      }
      if (send_keypress == 2) {
        //result |= 0x02;
        send_keypress = 0;
      }
      return result;
    }
    if (address == CIAADAT) {
      //if (send_keypress) {
        uint8_t c = 0, t = 0;
        pop_queued_key(&c, &t);
        t ^= 0x01;
        result = ((c << 1) | t) ^ 0xFF;
        send_keypress = 2;
        //M68K_SET_IRQ(0);
      //}
      return result;
    }
  }

  return result;
}

unsigned int m68k_read_memory_16(unsigned int address) {
  PLATFORM_CHECK_READ(OP_TYPE_WORD);

  /*if (m68k_get_reg(NULL, M68K_REG_PC) >= 0x080032F0 && m68k_get_reg(NULL, M68K_REG_PC) <= 0x080032F0 + 0x4000) {
    stop_cpu_emulation(1);
  }*/

  /*if (address >= 0xE90000 && address < 0xF00000) {
    printf("WORD read from DMAC @%.8X:", address);
    uint32_t v = cdtv_dmac_read(address & 0xFFFF, OP_TYPE_WORD);
    printf("%.2X\n", v);
    M68K_END_TIMESLICE;
    cpu_emulation_running = 0;
    return v;
  }*/

  if (mouse_hook_enabled) {
    if (address == JOY0DAT) {
      // Forward mouse valueses to Amyga.
      unsigned short result = (mouse_dy << 8) | (mouse_dx);
      return (unsigned int)result;
    }
    /*if (address == CIAAPRA) {
      unsigned short result = (unsigned int)read16((uint32_t)address);
      if (mouse_buttons & 0x01) {
        return (unsigned int)(result | 0x40);
      }
      else
          return (unsigned int)result;
    }*/
    if (address == POTGOR) {
      unsigned short result = (unsigned int)read16((uint32_t)address);
      // bit 1 rmb, bit 2 mmb
      if (mouse_buttons & 0x06) {
        return (unsigned int)((result ^ ((mouse_buttons & 0x02) << 9))   // move rmb to bit 10
                            & (result ^ ((mouse_buttons & 0x04) << 6))); // move mmb to bit 8
      }
      return (unsigned int)(result & 0xfffd);
    }
  }

  if (address & 0xFF000000)
    return 0;

  if (address & 0x01) {
    return ((read8(address) << 8) | read8(address + 1));
  }
  return (unsigned int)read16((uint32_t)address);
}

unsigned int m68k_read_memory_32(unsigned int address) {
  PLATFORM_CHECK_READ(OP_TYPE_LONGWORD);

  /*if (m68k_get_reg(NULL, M68K_REG_PC) >= 0x080032F0 && m68k_get_reg(NULL, M68K_REG_PC) <= 0x080032F0 + 0x4000) {
    stop_cpu_emulation(1);
  }*/

  /*if (address >= 0xE90000 && address < 0xF00000) {
    printf("LONGWORD read from DMAC @%.8X:", address);
    uint32_t v = cdtv_dmac_read(address & 0xFFFF, OP_TYPE_LONGWORD);
    printf("%.2X\n", v);
    M68K_END_TIMESLICE;
    cpu_emulation_running = 0;
    return v;
  }*/

  if (address & 0xFF000000)
    return 0;

  if (address & 0x01) {
    uint32_t c = read8(address);
    c |= (be16toh(read16(address+1)) << 8);
    c |= (read8(address + 3) << 24);
    return htobe32(c);
  }
  uint16_t a = read16(address);
  uint16_t b = read16(address + 2);
  return (a << 16) | b;
}

#define PLATFORM_CHECK_WRITE(a) \
  if (address >= cfg->custom_low && address < cfg->custom_high) { \
    switch(cfg->platform->id) { \
      case PLATFORM_AMIGA: { \
        if (address >= PISCSI_OFFSET && address < PISCSI_UPPER) { \
          handle_piscsi_write(address, value, a); \
        } \
        if (address >= PINET_OFFSET && address < PINET_UPPER) { \
          handle_pinet_write(address, value, a); \
        } \
        if (address >= PIGFX_RTG_BASE && address < PIGFX_UPPER) { \
          rtg_write((address & 0x0FFFFFFF), value, a); \
          return; \
        } \
        if (custom_write_amiga(cfg, address, value, a) != -1) { \
          return; \
        } \
        break; \
      } \
      default: \
        break; \
    } \
  } \
  if (address >= cfg->mapped_low && address < cfg->mapped_high) { \
    if (handle_mapped_write(cfg, address, value, a) != -1) \
      return; \
  }

void m68k_write_memory_8(unsigned int address, unsigned int value) {
  PLATFORM_CHECK_WRITE(OP_TYPE_BYTE);

  /*if (address >= 0xE90000 && address < 0xF00000) {
    printf("BYTE write to DMAC @%.8X: %.2X\n", address, value);
    cdtv_dmac_write(address & 0xFFFF, value, OP_TYPE_BYTE);
    M68K_END_TIMESLICE;
    cpu_emulation_running = 0;
    return;
  }*/

  if (address == 0xbfe001) {
    if (ovl != (value & (1 << 0))) {
      ovl = (value & (1 << 0));
      printf("OVL:%x\n", ovl);
    }
  }

  if (address & 0xFF000000)
    return;

  write8((uint32_t)address, value);
  return;
}

void m68k_write_memory_16(unsigned int address, unsigned int value) {
  PLATFORM_CHECK_WRITE(OP_TYPE_WORD);

  /*if (address >= 0xE90000 && address < 0xF00000) {
    printf("WORD write to DMAC @%.8X: %.4X\n", address, value);
    cdtv_dmac_write(address & 0xFFFF, value, OP_TYPE_WORD);
    M68K_END_TIMESLICE;
    cpu_emulation_running = 0;
    return;
  }*/

  if (address == 0xDFF030) {
    char *serdat = (char *)&value;
    // SERDAT word. see amiga dev docs appendix a; upper byte is control codes, and bit 0 is always 1.
    // ignore this upper byte as it's not viewable data, only display lower byte.
    printf("%c", serdat[0]);
  }
  if (address == 0xDFF09A) {
    if (!(value & 0x8000)) {
      if (value & 0x04) {
        int2_enabled = 0;
      }
    }
    else if (value & 0x04) {
      int2_enabled = 1;
    }
  }

  if (address & 0xFF000000)
    return;

  if (address & 0x01)
    printf("Unaligned WORD write!\n");

  write16((uint32_t)address, value);
  return;
}

void m68k_write_memory_32(unsigned int address, unsigned int value) {
  PLATFORM_CHECK_WRITE(OP_TYPE_LONGWORD);

  /*if (address >= 0xE90000 && address < 0xF00000) {
    printf("LONGWORD write to DMAC @%.8X: %.8X\n", address, value);
    cdtv_dmac_write(address & 0xFFFF, value, OP_TYPE_LONGWORD);
    M68K_END_TIMESLICE;
    cpu_emulation_running = 0;
    return;
  }*/

  if (address & 0xFF000000)
    return;

  if (address & 0x01)
    printf("Unaligned LONGWORD write!\n");

  write16(address, value >> 16);
  write16(address + 2, value);
  return;
}