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bsnes/Core/gb.c

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#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#ifndef _WIN32
#include <sys/select.h>
#include <unistd.h>
#endif
#include "gb.h"
/* The libretro frontend does not link against rewind.c, so we provide empty weak alternatives to its functions */
void __attribute__((weak)) GB_rewind_free(GB_gameboy_t *gb) { }
void __attribute__((weak)) GB_rewind_push(GB_gameboy_t *gb) { }
void GB_attributed_logv(GB_gameboy_t *gb, GB_log_attributes attributes, const char *fmt, va_list args)
{
char *string = NULL;
vasprintf(&string, fmt, args);
if (string) {
if (gb->log_callback) {
gb->log_callback(gb, string, attributes);
}
else {
/* Todo: Add ANSI escape sequences for attributed text */
printf("%s", string);
}
}
free(string);
}
void GB_attributed_log(GB_gameboy_t *gb, GB_log_attributes attributes, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
GB_attributed_logv(gb, attributes, fmt, args);
va_end(args);
}
void GB_log(GB_gameboy_t *gb, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
GB_attributed_logv(gb, 0, fmt, args);
va_end(args);
}
#ifndef DISABLE_DEBUGGER
static char *default_input_callback(GB_gameboy_t *gb)
{
char *expression = NULL;
size_t size = 0;
if (getline(&expression, &size, stdin) == -1) {
/* The user doesn't have STDIN or used ^D. We make sure the program keeps running. */
GB_set_async_input_callback(gb, NULL); /* Disable async input */
return strdup("c");
}
if (!expression) {
return strdup("");
}
size_t length = strlen(expression);
if (expression[length - 1] == '\n') {
expression[length - 1] = 0;
}
return expression;
}
static char *default_async_input_callback(GB_gameboy_t *gb)
{
#ifndef _WIN32
fd_set set;
FD_ZERO(&set);
FD_SET(STDIN_FILENO, &set);
struct timeval time = {0,};
if (select(1, &set, NULL, NULL, &time) == 1) {
if (feof(stdin)) {
GB_set_async_input_callback(gb, NULL); /* Disable async input */
return NULL;
}
return default_input_callback(gb);
}
#endif
return NULL;
}
#endif
void GB_init(GB_gameboy_t *gb)
{
memset(gb, 0, sizeof(*gb));
gb->ram = malloc(gb->ram_size = 0x2000);
gb->vram = malloc(gb->vram_size = 0x2000);
#ifndef DISABLE_DEBUGGER
gb->input_callback = default_input_callback;
gb->async_input_callback = default_async_input_callback;
#endif
gb->cartridge_type = &GB_cart_defs[0]; // Default cartridge type
gb->clock_multiplier = 1.0;
GB_reset(gb);
}
void GB_init_cgb(GB_gameboy_t *gb)
{
memset(gb, 0, sizeof(*gb));
gb->ram = malloc(gb->ram_size = 0x2000 * 8);
gb->vram = malloc(gb->vram_size = 0x2000 * 2);
gb->is_cgb = true;
#ifndef DISABLE_DEBUGGER
gb->input_callback = default_input_callback;
gb->async_input_callback = default_async_input_callback;
#endif
gb->cartridge_type = &GB_cart_defs[0]; // Default cartridge type
gb->clock_multiplier = 1.0;
GB_reset(gb);
}
void GB_free(GB_gameboy_t *gb)
{
gb->magic = 0;
if (gb->ram) {
free(gb->ram);
}
if (gb->vram) {
free(gb->vram);
}
if (gb->mbc_ram) {
free(gb->mbc_ram);
}
if (gb->rom) {
free(gb->rom);
}
if (gb->apu_output.buffer) {
free(gb->apu_output.buffer);
}
if (gb->breakpoints) {
free(gb->breakpoints);
}
for (int i = 0x200; i--;) {
if (gb->bank_symbols[i]) {
GB_map_free(gb->bank_symbols[i]);
}
}
for (int i = 0x400; i--;) {
while (gb->reversed_symbol_map.buckets[i]) {
GB_symbol_t *next = gb->reversed_symbol_map.buckets[i]->next;
free(gb->reversed_symbol_map.buckets[i]);
gb->reversed_symbol_map.buckets[i] = next;
}
}
GB_rewind_free(gb);
memset(gb, 0, sizeof(*gb));
}
int GB_load_boot_rom(GB_gameboy_t *gb, const char *path)
{
FILE *f = fopen(path, "rb");
if (!f) {
GB_log(gb, "Could not open boot ROM: %s.\n", strerror(errno));
return errno;
}
fread(gb->boot_rom, sizeof(gb->boot_rom), 1, f);
fclose(f);
return 0;
}
void GB_load_boot_rom_from_buffer(GB_gameboy_t *gb, const unsigned char *buffer, size_t size)
{
if (size > sizeof(gb->boot_rom)) {
size = sizeof(gb->boot_rom);
}
memset(gb->boot_rom, 0xFF, sizeof(gb->boot_rom));
memcpy(gb->boot_rom, buffer, size);
}
int GB_load_rom(GB_gameboy_t *gb, const char *path)
{
FILE *f = fopen(path, "rb");
if (!f) {
GB_log(gb, "Could not open ROM: %s.\n", strerror(errno));
return errno;
}
fseek(f, 0, SEEK_END);
gb->rom_size = (ftell(f) + 0x3FFF) & ~0x3FFF; /* Round to bank */
/* And then round to a power of two */
while (gb->rom_size & (gb->rom_size - 1)) {
/* I promise this works. */
gb->rom_size |= gb->rom_size >> 1;
gb->rom_size++;
}
fseek(f, 0, SEEK_SET);
if (gb->rom) {
free(gb->rom);
}
gb->rom = malloc(gb->rom_size);
memset(gb->rom, 0xFF, gb->rom_size); /* Pad with 0xFFs */
fread(gb->rom, gb->rom_size, 1, f);
fclose(f);
GB_configure_cart(gb);
return 0;
}
int GB_save_battery(GB_gameboy_t *gb, const char *path)
{
if (!gb->cartridge_type->has_battery) return 0; // Nothing to save.
if (gb->mbc_ram_size == 0 && !gb->cartridge_type->has_rtc) return 0; /* Claims to have battery, but has no RAM or RTC */
FILE *f = fopen(path, "wb");
if (!f) {
GB_log(gb, "Could not open battery save: %s.\n", strerror(errno));
return errno;
}
if (fwrite(gb->mbc_ram, 1, gb->mbc_ram_size, f) != gb->mbc_ram_size) {
fclose(f);
return EIO;
}
if (gb->cartridge_type->has_rtc) {
if (fwrite(&gb->rtc_real, 1, sizeof(gb->rtc_real), f) != sizeof(gb->rtc_real)) {
fclose(f);
return EIO;
}
if (fwrite(&gb->last_rtc_second, 1, sizeof(gb->last_rtc_second), f) != sizeof(gb->last_rtc_second)) {
fclose(f);
return EIO;
}
}
errno = 0;
fclose(f);
return errno;
}
/* Loading will silently stop if the format is incomplete */
void GB_load_battery(GB_gameboy_t *gb, const char *path)
{
FILE *f = fopen(path, "rb");
if (!f) {
return;
}
if (fread(gb->mbc_ram, 1, gb->mbc_ram_size, f) != gb->mbc_ram_size) {
goto reset_rtc;
}
if (fread(&gb->rtc_real, 1, sizeof(gb->rtc_real), f) != sizeof(gb->rtc_real)) {
goto reset_rtc;
}
if (fread(&gb->last_rtc_second, 1, sizeof(gb->last_rtc_second), f) != sizeof(gb->last_rtc_second)) {
goto reset_rtc;
}
if (gb->last_rtc_second > time(NULL)) {
/* We must reset RTC here, or it will not advance. */
goto reset_rtc;
}
if (gb->last_rtc_second < 852076800) { /* 1/1/97. There weren't any RTC games that time,
so if the value we read is lower it means it wasn't
really RTC data. */
goto reset_rtc;
}
goto exit;
reset_rtc:
gb->last_rtc_second = time(NULL);
gb->rtc_real.high |= 0x80; /* This gives the game a hint that the clock should be reset. */
exit:
fclose(f);
return;
}
uint8_t GB_run(GB_gameboy_t *gb)
{
GB_debugger_run(gb);
gb->cycles_since_run = 0;
GB_cpu_run(gb);
if (gb->vblank_just_occured) {
GB_update_joyp(gb);
GB_rtc_run(gb);
GB_debugger_handle_async_commands(gb);
GB_rewind_push(gb);
}
return gb->cycles_since_run;
}
uint64_t GB_run_frame(GB_gameboy_t *gb)
{
/* Configure turbo temporarily, the user wants to handle FPS capping manually. */
bool old_turbo = gb->turbo;
bool old_dont_skip = gb->turbo_dont_skip;
gb->turbo = true;
gb->turbo_dont_skip = true;
gb->cycles_since_last_sync = 0;
while (true) {
GB_run(gb);
if (gb->vblank_just_occured) {
break;
}
}
gb->turbo = old_turbo;
gb->turbo_dont_skip = old_dont_skip;
return gb->cycles_since_last_sync * 1000000000LL / 2 / GB_get_clock_rate(gb); /* / 2 because we use 8MHz units */
}
void GB_set_pixels_output(GB_gameboy_t *gb, uint32_t *output)
{
gb->screen = output;
}
void GB_set_vblank_callback(GB_gameboy_t *gb, GB_vblank_callback_t callback)
{
gb->vblank_callback = callback;
}
void GB_set_log_callback(GB_gameboy_t *gb, GB_log_callback_t callback)
{
gb->log_callback = callback;
}
void GB_set_input_callback(GB_gameboy_t *gb, GB_input_callback_t callback)
{
#ifndef DISABLE_DEBUGGER
if (gb->input_callback == default_input_callback) {
gb->async_input_callback = NULL;
}
gb->input_callback = callback;
#endif
}
void GB_set_async_input_callback(GB_gameboy_t *gb, GB_input_callback_t callback)
{
#ifndef DISABLE_DEBUGGER
gb->async_input_callback = callback;
#endif
}
void GB_set_rgb_encode_callback(GB_gameboy_t *gb, GB_rgb_encode_callback_t callback)
{
if (!gb->rgb_encode_callback && !gb->is_cgb) {
gb->sprite_palettes_rgb[4] = gb->sprite_palettes_rgb[0] = gb->background_palettes_rgb[0] =
callback(gb, 0xFF, 0xFF, 0xFF);
gb->sprite_palettes_rgb[5] = gb->sprite_palettes_rgb[1] = gb->background_palettes_rgb[1] =
callback(gb, 0xAA, 0xAA, 0xAA);
gb->sprite_palettes_rgb[6] = gb->sprite_palettes_rgb[2] = gb->background_palettes_rgb[2] =
callback(gb, 0x55, 0x55, 0x55);
gb->sprite_palettes_rgb[7] = gb->sprite_palettes_rgb[3] = gb->background_palettes_rgb[3] =
callback(gb, 0, 0, 0);
}
gb->rgb_encode_callback = callback;
}
void GB_set_infrared_callback(GB_gameboy_t *gb, GB_infrared_callback_t callback)
{
gb->infrared_callback = callback;
}
void GB_set_infrared_input(GB_gameboy_t *gb, bool state)
{
gb->infrared_input = state;
gb->cycles_since_input_ir_change = 0;
gb->ir_queue_length = 0;
}
void GB_queue_infrared_input(GB_gameboy_t *gb, bool state, long cycles_after_previous_change)
{
if (gb->ir_queue_length == GB_MAX_IR_QUEUE) {
GB_log(gb, "IR Queue is full\n");
return;
}
gb->ir_queue[gb->ir_queue_length++] = (GB_ir_queue_item_t){state, cycles_after_previous_change};
}
void GB_set_rumble_callback(GB_gameboy_t *gb, GB_rumble_callback_t callback)
{
gb->rumble_callback = callback;
}
void GB_set_serial_transfer_start_callback(GB_gameboy_t *gb, GB_serial_transfer_start_callback_t callback)
{
gb->serial_transfer_start_callback = callback;
}
void GB_set_serial_transfer_end_callback(GB_gameboy_t *gb, GB_serial_transfer_end_callback_t callback)
{
gb->serial_transfer_end_callback = callback;
}
uint8_t GB_serial_get_data(GB_gameboy_t *gb)
{
if (gb->io_registers[GB_IO_SC] & 1) {
/* Internal Clock */
GB_log(gb, "Serial read request while using internal clock. \n");
return 0xFF;
}
return gb->io_registers[GB_IO_SB];
}
void GB_serial_set_data(GB_gameboy_t *gb, uint8_t data)
{
if (gb->io_registers[GB_IO_SC] & 1) {
/* Internal Clock */
GB_log(gb, "Serial write request while using internal clock. \n");
return;
}
gb->io_registers[GB_IO_SB] = data;
gb->io_registers[GB_IO_IF] |= 8;
}
void GB_disconnect_serial(GB_gameboy_t *gb)
{
gb->serial_transfer_start_callback = NULL;
gb->serial_transfer_end_callback = NULL;
/* Reset any internally-emulated device. Currently, only the printer. */
memset(&gb->printer, 0, sizeof(gb->printer));
}
bool GB_is_inited(GB_gameboy_t *gb)
{
return gb->magic == 'SAME';
}
bool GB_is_cgb(GB_gameboy_t *gb)
{
return gb->is_cgb;
}
void GB_set_turbo_mode(GB_gameboy_t *gb, bool on, bool no_frame_skip)
{
gb->turbo = on;
gb->turbo_dont_skip = no_frame_skip;
}
void GB_set_rendering_disabled(GB_gameboy_t *gb, bool disabled)
{
gb->disable_rendering = disabled;
}
void *GB_get_user_data(GB_gameboy_t *gb)
{
return gb->user_data;
}
void GB_set_user_data(GB_gameboy_t *gb, void *data)
{
gb->user_data = data;
}
void GB_reset(GB_gameboy_t *gb)
{
uint32_t mbc_ram_size = gb->mbc_ram_size;
bool cgb = gb->is_cgb;
memset(gb, 0, (size_t)GB_GET_SECTION((GB_gameboy_t *) 0, unsaved));
gb->version = GB_STRUCT_VERSION;
gb->mbc_rom_bank = 1;
gb->last_rtc_second = time(NULL);
gb->cgb_ram_bank = 1;
gb->io_registers[GB_IO_JOYP] = 0xF;
gb->mbc_ram_size = mbc_ram_size;
if (cgb) {
gb->ram_size = 0x2000 * 8;
memset(gb->ram, 0, gb->ram_size);
gb->vram_size = 0x2000 * 2;
memset(gb->vram, 0, gb->vram_size);
gb->is_cgb = true;
gb->cgb_mode = true;
gb->io_registers[GB_IO_OBP0] = gb->io_registers[GB_IO_OBP1] = 0x00;
}
else {
gb->ram_size = 0x2000;
memset(gb->ram, 0, gb->ram_size);
gb->vram_size = 0x2000;
memset(gb->vram, 0, gb->vram_size);
if (gb->rgb_encode_callback) {
gb->sprite_palettes_rgb[4] = gb->sprite_palettes_rgb[0] = gb->background_palettes_rgb[0] =
gb->rgb_encode_callback(gb, 0xFF, 0xFF, 0xFF);
gb->sprite_palettes_rgb[5] = gb->sprite_palettes_rgb[1] = gb->background_palettes_rgb[1] =
gb->rgb_encode_callback(gb, 0xAA, 0xAA, 0xAA);
gb->sprite_palettes_rgb[6] = gb->sprite_palettes_rgb[2] = gb->background_palettes_rgb[2] =
gb->rgb_encode_callback(gb, 0x55, 0x55, 0x55);
gb->sprite_palettes_rgb[7] = gb->sprite_palettes_rgb[3] = gb->background_palettes_rgb[3] =
gb->rgb_encode_callback(gb, 0, 0, 0);
}
gb->io_registers[GB_IO_OBP0] = gb->io_registers[GB_IO_OBP1] = 0xFF;
}
/* The serial interrupt always occur on the 0xF7th cycle of every 0x100 cycle since boot. */
gb->serial_cycles = 0x100-0xF7;
gb->io_registers[GB_IO_SC] = 0x7E;
gb->magic = (uintptr_t)'SAME';
}
void GB_switch_model_and_reset(GB_gameboy_t *gb, bool is_cgb)
{
if (is_cgb) {
gb->ram = realloc(gb->ram, gb->ram_size = 0x2000 * 8);
gb->vram = realloc(gb->vram, gb->vram_size = 0x2000 * 2);
}
else {
gb->ram = realloc(gb->ram, gb->ram_size = 0x2000);
gb->vram = realloc(gb->vram, gb->vram_size = 0x2000);
}
gb->is_cgb = is_cgb;
GB_rewind_free(gb);
GB_reset(gb);
}
void *GB_get_direct_access(GB_gameboy_t *gb, GB_direct_access_t access, size_t *size, uint16_t *bank)
{
/* Set size and bank to dummy pointers if not set */
size_t dummy_size;
uint16_t dummy_bank;
if (!size) {
size = &dummy_size;
}
if (!bank) {
bank = &dummy_bank;
}
switch (access) {
case GB_DIRECT_ACCESS_ROM:
*size = gb->rom_size;
*bank = gb->mbc_rom_bank;
return gb->rom;
case GB_DIRECT_ACCESS_RAM:
*size = gb->ram_size;
*bank = gb->cgb_ram_bank;
return gb->ram;
case GB_DIRECT_ACCESS_CART_RAM:
*size = gb->mbc_ram_size;
*bank = gb->mbc_ram_bank;
return gb->mbc_ram;
case GB_DIRECT_ACCESS_VRAM:
*size = gb->vram_size;
*bank = gb->cgb_vram_bank;
return gb->vram;
case GB_DIRECT_ACCESS_HRAM:
*size = sizeof(gb->hram);
*bank = 0;
return &gb->hram;
case GB_DIRECT_ACCESS_IO:
*size = sizeof(gb->io_registers);
*bank = 0;
return &gb->io_registers;
case GB_DIRECT_ACCESS_BOOTROM:
*size = gb->is_cgb? sizeof(gb->boot_rom) : 0x100;
*bank = 0;
return &gb->boot_rom;
case GB_DIRECT_ACCESS_OAM:
*size = sizeof(gb->oam);
*bank = 0;
return &gb->oam;
case GB_DIRECT_ACCESS_BGP:
*size = sizeof(gb->background_palettes_data);
*bank = 0;
return &gb->background_palettes_data;
case GB_DIRECT_ACCESS_OBP:
*size = sizeof(gb->sprite_palettes_data);
*bank = 0;
return &gb->sprite_palettes_data;
case GB_DIRECT_ACCESS_IE:
*size = sizeof(gb->interrupt_enable);
*bank = 0;
return &gb->interrupt_enable;
default:
*size = 0;
*bank = 0;
return NULL;
}
}
void GB_set_clock_multiplier(GB_gameboy_t *gb, double multiplier)
{
gb->clock_multiplier = multiplier;
}
uint32_t GB_get_clock_rate(GB_gameboy_t *gb)
{
return CPU_FREQUENCY * gb->clock_multiplier;
}
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