1460 lines
54 KiB
C
1460 lines
54 KiB
C
#include <stdio.h>
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#include <stdbool.h>
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#include "gb.h"
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typedef uint8_t GB_read_function_t(GB_gameboy_t *gb, uint16_t addr);
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typedef void GB_write_function_t(GB_gameboy_t *gb, uint16_t addr, uint8_t value);
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typedef enum {
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GB_BUS_MAIN, /* In DMG: Cart and RAM. In CGB: Cart only */
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GB_BUS_RAM, /* In CGB only. */
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GB_BUS_VRAM,
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GB_BUS_INTERNAL, /* Anything in highram. Might not be the most correct name. */
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} GB_bus_t;
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static GB_bus_t bus_for_addr(GB_gameboy_t *gb, uint16_t addr)
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{
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if (addr < 0x8000) {
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return GB_BUS_MAIN;
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}
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if (addr < 0xA000) {
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return GB_BUS_VRAM;
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}
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if (addr < 0xC000) {
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return GB_BUS_MAIN;
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}
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if (addr < 0xFE00) {
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return GB_is_cgb(gb)? GB_BUS_RAM : GB_BUS_MAIN;
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}
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return GB_BUS_INTERNAL;
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}
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static uint16_t bitwise_glitch(uint16_t a, uint16_t b, uint16_t c)
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{
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return ((a ^ c) & (b ^ c)) ^ c;
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}
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static uint16_t bitwise_glitch_read(uint16_t a, uint16_t b, uint16_t c)
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{
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return b | (a & c);
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}
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static uint16_t bitwise_glitch_read_secondary(uint16_t a, uint16_t b, uint16_t c, uint16_t d)
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{
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return (b & (a | c | d)) | (a & c & d);
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}
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/*
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Used on the MGB in some scenarios
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static uint16_t bitwise_glitch_mgb(uint16_t a, uint16_t b, uint16_t c, uint16_t d, uint16_t e, bool variant)
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{
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return (c & (e | d | b | (variant? 0 : a))) | (b & d & (a | e));
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}
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*/
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static uint16_t bitwise_glitch_tertiary_read_1(uint16_t a, uint16_t b, uint16_t c, uint16_t d, uint16_t e)
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{
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return c | (a & b & d & e);
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}
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static uint16_t bitwise_glitch_tertiary_read_2(uint16_t a, uint16_t b, uint16_t c, uint16_t d, uint16_t e)
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{
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return (c & (a | b | d | e)) | (a & b & d & e);
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}
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static uint16_t bitwise_glitch_tertiary_read_3(uint16_t a, uint16_t b, uint16_t c, uint16_t d, uint16_t e)
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{
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return (c & (a | b | d | e)) | (b & d & e);
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}
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static uint16_t bitwise_glitch_quaternary_read_dmg(uint16_t a, uint16_t b, uint16_t c, uint16_t d,
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uint16_t e, uint16_t f, uint16_t g, uint16_t h)
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{
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/* On my DMG, some cases are non-deterministic, while on some other DMGs they yield constant zeros.
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The non deterministic cases are affected by (on the row 40 case) 34, 36, 3e and 28, and potentially
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others. For my own sanity I'm going to emulate the DMGs that output zeros. */
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(void)a;
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return (e & (h | g | (~d & f) | c | b)) | (c & g & h);
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}
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/*
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// Oh my.
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static uint16_t bitwise_glitch_quaternary_read_mgb(uint16_t a, uint16_t b, uint16_t c, uint16_t d,
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uint16_t e, uint16_t f, uint16_t g, uint16_t h)
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{
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return (e & (h | g | c | (a & b))) | ((c & h) & (g & (~f | b | a | ~d) | (a & b & f)));
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}
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*/
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static uint16_t bitwise_glitch_quaternary_read_sgb2(uint16_t a, uint16_t b, uint16_t c, uint16_t d,
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uint16_t e, uint16_t f, uint16_t g, uint16_t h)
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{
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return (e & (h | g | c | (a & b))) | ((c & g & h) & (b | a | ~f));
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}
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void GB_trigger_oam_bug(GB_gameboy_t *gb, uint16_t address)
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{
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if (GB_is_cgb(gb)) return;
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if (address >= 0xFE00 && address < 0xFF00) {
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if (gb->accessed_oam_row != 0xff && gb->accessed_oam_row >= 8) {
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uint16_t *base = (uint16_t *)(gb->oam + gb->accessed_oam_row);
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base[0] = bitwise_glitch(base[0],
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base[-4],
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base[-2]);
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for (unsigned i = 2; i < 8; i++) {
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gb->oam[gb->accessed_oam_row + i] = gb->oam[gb->accessed_oam_row - 8 + i];
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}
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}
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}
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}
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static void oam_bug_secondary_read_corruption(GB_gameboy_t *gb)
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{
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if (gb->accessed_oam_row < 0x98) {
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uint16_t *base = (uint16_t *)(gb->oam + gb->accessed_oam_row);
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base[-4] = bitwise_glitch_read_secondary(base[-8],
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base[-4],
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base[0],
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base[-2]);
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for (unsigned i = 0; i < 8; i++) {
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gb->oam[gb->accessed_oam_row - 0x10 + i] = gb->oam[gb->accessed_oam_row - 0x08 + i];
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}
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}
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}
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/*
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static void oam_bug_tertiary_read_corruption_mgb(GB_gameboy_t *gb)
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{
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if (gb->accessed_oam_row < 0x98) {
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uint16_t *base = (uint16_t *)(gb->oam + gb->accessed_oam_row);
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uint16_t temp = bitwise_glitch_mgb(
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base[0],
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base[-2],
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base[-4],
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base[-8],
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base[-16],
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true);
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base[-4] = bitwise_glitch_mgb(
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base[0],
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base[-2],
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base[-4],
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base[-8],
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base[-16],
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false);
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for (unsigned i = 0; i < 8; i++) {
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gb->oam[gb->accessed_oam_row - 0x10 + i] = gb->oam[gb->accessed_oam_row - 0x20 + i] = gb->oam[gb->accessed_oam_row - 0x08 + i];
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}
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base[-8] = temp;
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base[-16] = temp;
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}
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}
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*/
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static void oam_bug_quaternary_read_corruption(GB_gameboy_t *gb, typeof(bitwise_glitch_quaternary_read_dmg) *bitwise_op)
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{
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if (gb->accessed_oam_row < 0x98) {
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uint16_t *base = (uint16_t *)(gb->oam + gb->accessed_oam_row);
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base[-4] = bitwise_op(*(uint16_t *)gb->oam,
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base[0],
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base[-2],
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base[-3],
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base[-4],
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base[-7],
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base[-8],
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base[-16]);
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for (unsigned i = 0; i < 8; i++) {
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gb->oam[gb->accessed_oam_row - 0x10 + i] = gb->oam[gb->accessed_oam_row - 0x20 + i] = gb->oam[gb->accessed_oam_row - 0x08 + i];
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}
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}
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}
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static void oam_bug_tertiary_read_corruption(GB_gameboy_t *gb, typeof(bitwise_glitch_tertiary_read_1) *bitwise_op)
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{
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if (gb->accessed_oam_row < 0x98) {
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uint16_t *base = (uint16_t *)(gb->oam + gb->accessed_oam_row);
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/* On some instances, the corruption row is copied to the first row for some accessed row. On my DMG it happens
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for row 80, and on my MGB it happens on row 60. Some instances only copy odd or even bytes. Additionally,
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for some instances on accessed rows that do not affect the first row, the last two bytes of the preceeding
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row are also corrupted in a non-deterministic probability. */
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base[-4] = bitwise_op(
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base[0],
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base[-2],
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base[-4],
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base[-8],
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base[-16]);
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for (unsigned i = 0; i < 8; i++) {
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gb->oam[gb->accessed_oam_row - 0x10 + i] = gb->oam[gb->accessed_oam_row - 0x20 + i] = gb->oam[gb->accessed_oam_row - 0x08 + i];
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}
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}
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}
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void GB_trigger_oam_bug_read(GB_gameboy_t *gb, uint16_t address)
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{
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if (GB_is_cgb(gb)) return;
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if (address >= 0xFE00 && address < 0xFF00) {
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if (gb->accessed_oam_row != 0xff && gb->accessed_oam_row >= 8) {
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if ((gb->accessed_oam_row & 0x18) == 0x10) {
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oam_bug_secondary_read_corruption(gb);
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}
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else if ((gb->accessed_oam_row & 0x18) == 0x00) {
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/* Everything in this specific case is *extremely* revision and instance specific. */
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if (gb->model == GB_MODEL_MGB) {
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/* TODO: This is rather simplified, research further */
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oam_bug_tertiary_read_corruption(gb, bitwise_glitch_tertiary_read_3);
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}
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else if (gb->accessed_oam_row == 0x40) {
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oam_bug_quaternary_read_corruption(gb,
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((gb->model & ~GB_MODEL_NO_SFC_BIT) == GB_MODEL_SGB2)?
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bitwise_glitch_quaternary_read_sgb2:
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bitwise_glitch_quaternary_read_dmg);
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}
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else if ((gb->model & ~GB_MODEL_NO_SFC_BIT) != GB_MODEL_SGB2) {
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if (gb->accessed_oam_row == 0x20) {
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oam_bug_tertiary_read_corruption(gb, bitwise_glitch_tertiary_read_2);
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}
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else if (gb->accessed_oam_row == 0x60) {
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oam_bug_tertiary_read_corruption(gb, bitwise_glitch_tertiary_read_3);
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}
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else {
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oam_bug_tertiary_read_corruption(gb, bitwise_glitch_tertiary_read_1);
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}
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}
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else {
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oam_bug_tertiary_read_corruption(gb, bitwise_glitch_tertiary_read_2);
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}
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}
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else {
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uint16_t *base = (uint16_t *)(gb->oam + gb->accessed_oam_row);
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base[-4] =
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base[0] = bitwise_glitch_read(base[0],
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base[-4],
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base[-2]);
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}
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for (unsigned i = 0; i < 8; i++) {
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gb->oam[gb->accessed_oam_row + i] = gb->oam[gb->accessed_oam_row - 8 + i];
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}
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if (gb->accessed_oam_row == 0x80) {
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memcpy(gb->oam, gb->oam + gb->accessed_oam_row, 8);
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}
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else if (gb->model == GB_MODEL_MGB && gb->accessed_oam_row == 0x40) {
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memcpy(gb->oam, gb->oam + gb->accessed_oam_row, 8);
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}
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}
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}
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}
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static bool is_addr_in_dma_use(GB_gameboy_t *gb, uint16_t addr)
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{
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if (!gb->dma_steps_left || (gb->dma_cycles < 0 && !gb->is_dma_restarting) || addr >= 0xFE00) return false;
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return bus_for_addr(gb, addr) == bus_for_addr(gb, gb->dma_current_src);
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}
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static uint8_t read_rom(GB_gameboy_t *gb, uint16_t addr)
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{
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if (addr < 0x100 && !gb->boot_rom_finished) {
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return gb->boot_rom[addr];
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}
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if (addr >= 0x200 && addr < 0x900 && GB_is_cgb(gb) && !gb->boot_rom_finished) {
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return gb->boot_rom[addr];
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}
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if (!gb->rom_size) {
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return 0xFF;
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}
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unsigned effective_address = (addr & 0x3FFF) + gb->mbc_rom0_bank * 0x4000;
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return gb->rom[effective_address & (gb->rom_size - 1)];
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}
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static uint8_t read_mbc_rom(GB_gameboy_t *gb, uint16_t addr)
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{
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unsigned effective_address = (addr & 0x3FFF) + gb->mbc_rom_bank * 0x4000;
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return gb->rom[effective_address & (gb->rom_size - 1)];
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}
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static uint8_t read_vram(GB_gameboy_t *gb, uint16_t addr)
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{
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if (gb->vram_read_blocked) {
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return 0xFF;
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}
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if (gb->display_state == 22 && GB_is_cgb(gb) && !gb->cgb_double_speed) {
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if (addr & 0x1000) {
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addr = gb->last_tile_index_address;
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}
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else if (gb->last_tile_data_address & 0x1000) {
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/* TODO: This is case is more complicated then the rest and differ between revisions
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It's probably affected by how VRAM is layed out, might be easier after a decap is done*/
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}
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else {
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addr = gb->last_tile_data_address;
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}
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}
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return gb->vram[(addr & 0x1FFF) + (gb->cgb_vram_bank? 0x2000 : 0)];
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}
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static uint8_t read_mbc_ram(GB_gameboy_t *gb, uint16_t addr)
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{
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if (gb->cartridge_type->mbc_type == GB_HUC3) {
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switch (gb->huc3_mode) {
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case 0xC: // RTC read
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if (gb->huc3_access_flags == 0x2) {
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return 1;
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}
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return gb->huc3_read;
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case 0xD: // RTC status
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return 1;
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case 0xE: // IR mode
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return gb->effective_ir_input; // TODO: What are the other bits?
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default:
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GB_log(gb, "Unsupported HuC-3 mode %x read: %04x\n", gb->huc3_mode, addr);
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return 1; // TODO: What happens in this case?
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case 0: // TODO: R/O RAM? (or is it disabled?)
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case 0xA: // RAM
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break;
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}
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}
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if (gb->cartridge_type->mbc_type == GB_TPP1) {
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switch (gb->tpp1_mode) {
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case 0:
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switch (addr & 3) {
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case 0: return gb->tpp1_rom_bank;
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case 1: return gb->tpp1_rom_bank >> 8;
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case 2: return gb->tpp1_ram_bank;
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case 3: return gb->rumble_strength | gb->tpp1_mr4;
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}
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case 2:
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case 3:
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break; // Read RAM
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case 5:
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return gb->rtc_latched.data[(addr & 3) ^ 3];
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default:
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return 0xFF;
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}
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}
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else if ((!gb->mbc_ram_enable) &&
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gb->cartridge_type->mbc_subtype != GB_CAMERA &&
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gb->cartridge_type->mbc_type != GB_HUC1 &&
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gb->cartridge_type->mbc_type != GB_HUC3) {
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return 0xFF;
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}
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if (gb->cartridge_type->mbc_type == GB_HUC1 && gb->huc1.ir_mode) {
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return 0xc0 | gb->effective_ir_input;
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}
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if (gb->cartridge_type->has_rtc && gb->cartridge_type->mbc_type != GB_HUC3 &&
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gb->mbc3_rtc_mapped) {
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/* RTC read */
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if (gb->mbc_ram_bank <= 4) {
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gb->rtc_latched.seconds &= 0x3F;
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gb->rtc_latched.minutes &= 0x3F;
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gb->rtc_latched.hours &= 0x1F;
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gb->rtc_latched.high &= 0xC1;
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return gb->rtc_latched.data[gb->mbc_ram_bank];
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}
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return 0xFF;
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}
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if (gb->camera_registers_mapped) {
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return GB_camera_read_register(gb, addr);
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}
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if (!gb->mbc_ram || !gb->mbc_ram_size) {
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return 0xFF;
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}
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if (gb->cartridge_type->mbc_subtype == GB_CAMERA && gb->mbc_ram_bank == 0 && addr >= 0xa100 && addr < 0xaf00) {
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return GB_camera_read_image(gb, addr - 0xa100);
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}
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uint8_t effective_bank = gb->mbc_ram_bank;
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if (gb->cartridge_type->mbc_type == GB_MBC3 && !gb->is_mbc30) {
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if (gb->cartridge_type->has_rtc) {
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if (effective_bank > 3) return 0xFF;
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}
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effective_bank &= 0x3;
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}
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uint8_t ret = gb->mbc_ram[((addr & 0x1FFF) + effective_bank * 0x2000) & (gb->mbc_ram_size - 1)];
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if (gb->cartridge_type->mbc_type == GB_MBC2) {
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ret |= 0xF0;
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}
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return ret;
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}
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static uint8_t read_ram(GB_gameboy_t *gb, uint16_t addr)
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{
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return gb->ram[addr & 0x0FFF];
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}
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static uint8_t read_banked_ram(GB_gameboy_t *gb, uint16_t addr)
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{
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return gb->ram[(addr & 0x0FFF) + gb->cgb_ram_bank * 0x1000];
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}
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static uint8_t read_high_memory(GB_gameboy_t *gb, uint16_t addr)
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{
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if (gb->hdma_on) {
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return gb->last_opcode_read;
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}
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if (addr < 0xFE00) {
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return read_banked_ram(gb, addr);
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}
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if (addr < 0xFF00) {
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if (gb->oam_write_blocked && !GB_is_cgb(gb)) {
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GB_trigger_oam_bug_read(gb, addr);
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return 0xff;
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}
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if ((gb->dma_steps_left && (gb->dma_cycles > 0 || gb->is_dma_restarting))) {
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/* Todo: Does reading from OAM during DMA causes the OAM bug? */
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return 0xff;
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}
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if (gb->oam_read_blocked) {
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if (!GB_is_cgb(gb)) {
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if (addr < 0xFEA0) {
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uint16_t *oam = (uint16_t *)gb->oam;
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if (gb->accessed_oam_row == 0) {
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oam[(addr & 0xf8) >> 1] =
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oam[0] = bitwise_glitch_read(oam[0],
|
|
oam[(addr & 0xf8) >> 1],
|
|
oam[(addr & 0xff) >> 1]);
|
|
|
|
for (unsigned i = 2; i < 8; i++) {
|
|
gb->oam[i] = gb->oam[(addr & 0xf8) + i];
|
|
}
|
|
}
|
|
else if (gb->accessed_oam_row == 0xa0) {
|
|
uint8_t target = (addr & 7) | 0x98;
|
|
uint16_t a = oam[0x9c >> 1],
|
|
b = oam[target >> 1],
|
|
c = oam[(addr & 0xf8) >> 1];
|
|
switch (addr & 7) {
|
|
case 0:
|
|
case 1:
|
|
/* Probably instance specific */
|
|
if ((gb->model & GB_MODEL_FAMILY_MASK) == GB_MODEL_DMG_FAMILY) {
|
|
oam[target >> 1] = (a & b) | (a & c) | (b & c);
|
|
}
|
|
else {
|
|
oam[target >> 1] = bitwise_glitch_read(a, b, c);
|
|
}
|
|
break;
|
|
case 2:
|
|
case 3: {
|
|
/* Probably instance specific */
|
|
c = oam[(addr & 0xfe) >> 1];
|
|
|
|
// MGB only: oam[target >> 1] = bitwise_glitch_read(a, b, c);
|
|
oam[target >> 1] = (a & b) | (a & c) | (b & c);
|
|
break;
|
|
}
|
|
case 4:
|
|
case 5:
|
|
break; // No additional corruption
|
|
case 6:
|
|
case 7:
|
|
oam[target >> 1] = bitwise_glitch_read(a, b, c);
|
|
break;
|
|
|
|
default:
|
|
__builtin_unreachable();
|
|
}
|
|
|
|
for (unsigned i = 0; i < 8; i++) {
|
|
gb->oam[(addr & 0xf8) + i] = gb->oam[0x98 + i];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return 0xff;
|
|
}
|
|
|
|
if (addr < 0xFEA0) {
|
|
return gb->oam[addr & 0xFF];
|
|
}
|
|
|
|
if (gb->oam_read_blocked) {
|
|
return 0xFF;
|
|
}
|
|
|
|
switch (gb->model) {
|
|
case GB_MODEL_CGB_E:
|
|
case GB_MODEL_AGB:
|
|
return (addr & 0xF0) | ((addr >> 4) & 0xF);
|
|
|
|
case GB_MODEL_CGB_D:
|
|
if (addr > 0xfec0) {
|
|
addr |= 0xf0;
|
|
}
|
|
return gb->extra_oam[addr - 0xfea0];
|
|
|
|
case GB_MODEL_CGB_C:
|
|
case GB_MODEL_CGB_B:
|
|
// case GB_MODEL_CGB_A:
|
|
case GB_MODEL_CGB_0:
|
|
addr &= ~0x18;
|
|
return gb->extra_oam[addr - 0xfea0];
|
|
|
|
case GB_MODEL_DMG_B:
|
|
case GB_MODEL_MGB:
|
|
case GB_MODEL_SGB_NTSC:
|
|
case GB_MODEL_SGB_PAL:
|
|
case GB_MODEL_SGB_NTSC_NO_SFC:
|
|
case GB_MODEL_SGB_PAL_NO_SFC:
|
|
case GB_MODEL_SGB2:
|
|
case GB_MODEL_SGB2_NO_SFC:
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (addr < 0xFF00) {
|
|
return 0;
|
|
}
|
|
|
|
if (addr < 0xFF80) {
|
|
switch (addr & 0xFF) {
|
|
case GB_IO_IF:
|
|
return gb->io_registers[GB_IO_IF] | 0xE0;
|
|
case GB_IO_TAC:
|
|
return gb->io_registers[GB_IO_TAC] | 0xF8;
|
|
case GB_IO_STAT:
|
|
return gb->io_registers[GB_IO_STAT] | 0x80;
|
|
case GB_IO_OPRI:
|
|
if (!GB_is_cgb(gb)) {
|
|
return 0xFF;
|
|
}
|
|
return gb->io_registers[GB_IO_OPRI] | 0xFE;
|
|
|
|
case GB_IO_PCM_12:
|
|
if (!GB_is_cgb(gb)) return 0xFF;
|
|
return ((gb->apu.is_active[GB_SQUARE_2] ? (gb->apu.samples[GB_SQUARE_2] << 4) : 0) |
|
|
(gb->apu.is_active[GB_SQUARE_1] ? (gb->apu.samples[GB_SQUARE_1]) : 0)) & (gb->model <= GB_MODEL_CGB_C? gb->apu.pcm_mask[0] : 0xFF);
|
|
case GB_IO_PCM_34:
|
|
if (!GB_is_cgb(gb)) return 0xFF;
|
|
return ((gb->apu.is_active[GB_NOISE] ? (gb->apu.samples[GB_NOISE] << 4) : 0) |
|
|
(gb->apu.is_active[GB_WAVE] ? (gb->apu.samples[GB_WAVE]) : 0)) & (gb->model <= GB_MODEL_CGB_C? gb->apu.pcm_mask[1] : 0xFF);
|
|
case GB_IO_JOYP:
|
|
GB_timing_sync(gb);
|
|
case GB_IO_TMA:
|
|
case GB_IO_LCDC:
|
|
case GB_IO_SCY:
|
|
case GB_IO_SCX:
|
|
case GB_IO_LY:
|
|
case GB_IO_LYC:
|
|
case GB_IO_BGP:
|
|
case GB_IO_OBP0:
|
|
case GB_IO_OBP1:
|
|
case GB_IO_WY:
|
|
case GB_IO_WX:
|
|
case GB_IO_SC:
|
|
case GB_IO_SB:
|
|
case GB_IO_DMA:
|
|
return gb->io_registers[addr & 0xFF];
|
|
case GB_IO_TIMA:
|
|
if (gb->tima_reload_state == GB_TIMA_RELOADING) {
|
|
return 0;
|
|
}
|
|
return gb->io_registers[GB_IO_TIMA];
|
|
case GB_IO_DIV:
|
|
return gb->div_counter >> 8;
|
|
case GB_IO_HDMA5:
|
|
if (!gb->cgb_mode) return 0xFF;
|
|
return ((gb->hdma_on || gb->hdma_on_hblank)? 0 : 0x80) | ((gb->hdma_steps_left - 1) & 0x7F);
|
|
case GB_IO_SVBK:
|
|
if (!gb->cgb_mode) {
|
|
return 0xFF;
|
|
}
|
|
return gb->cgb_ram_bank | ~0x7;
|
|
case GB_IO_VBK:
|
|
if (!GB_is_cgb(gb)) {
|
|
return 0xFF;
|
|
}
|
|
return gb->cgb_vram_bank | ~0x1;
|
|
|
|
/* Todo: It seems that a CGB in DMG mode can access BGPI and OBPI, but not BGPD and OBPD? */
|
|
case GB_IO_BGPI:
|
|
case GB_IO_OBPI:
|
|
if (!GB_is_cgb(gb)) {
|
|
return 0xFF;
|
|
}
|
|
return gb->io_registers[addr & 0xFF] | 0x40;
|
|
|
|
case GB_IO_BGPD:
|
|
case GB_IO_OBPD:
|
|
{
|
|
if (!gb->cgb_mode && gb->boot_rom_finished) {
|
|
return 0xFF;
|
|
}
|
|
if (gb->cgb_palettes_blocked) {
|
|
return 0xFF;
|
|
}
|
|
uint8_t index_reg = (addr & 0xFF) - 1;
|
|
return ((addr & 0xFF) == GB_IO_BGPD?
|
|
gb->background_palettes_data :
|
|
gb->sprite_palettes_data)[gb->io_registers[index_reg] & 0x3F];
|
|
}
|
|
|
|
case GB_IO_KEY1:
|
|
if (!gb->cgb_mode) {
|
|
return 0xFF;
|
|
}
|
|
return (gb->io_registers[GB_IO_KEY1] & 0x7F) | (gb->cgb_double_speed? 0xFE : 0x7E);
|
|
|
|
case GB_IO_RP: {
|
|
if (!gb->cgb_mode) return 0xFF;
|
|
/* You will read your own IR LED if it's on. */
|
|
uint8_t ret = (gb->io_registers[GB_IO_RP] & 0xC1) | 0x2E;
|
|
if (gb->model != GB_MODEL_CGB_E) {
|
|
ret |= 0x10;
|
|
}
|
|
if (((gb->io_registers[GB_IO_RP] & 0xC0) == 0xC0 && gb->effective_ir_input) && gb->model != GB_MODEL_AGB) {
|
|
ret &= ~2;
|
|
}
|
|
return ret;
|
|
}
|
|
case GB_IO_UNKNOWN2:
|
|
case GB_IO_UNKNOWN3:
|
|
return GB_is_cgb(gb)? gb->io_registers[addr & 0xFF] : 0xFF;
|
|
case GB_IO_UNKNOWN4:
|
|
return gb->cgb_mode? gb->io_registers[addr & 0xFF] : 0xFF;
|
|
case GB_IO_UNKNOWN5:
|
|
return GB_is_cgb(gb)? gb->io_registers[addr & 0xFF] | 0x8F : 0xFF;
|
|
default:
|
|
if ((addr & 0xFF) >= GB_IO_NR10 && (addr & 0xFF) <= GB_IO_WAV_END) {
|
|
return GB_apu_read(gb, addr & 0xFF);
|
|
}
|
|
return 0xFF;
|
|
}
|
|
__builtin_unreachable();
|
|
}
|
|
|
|
if (addr == 0xFFFF) {
|
|
/* Interrupt Mask */
|
|
return gb->interrupt_enable;
|
|
}
|
|
|
|
/* HRAM */
|
|
return gb->hram[addr - 0xFF80];
|
|
}
|
|
|
|
static GB_read_function_t * const read_map[] =
|
|
{
|
|
read_rom, read_rom, read_rom, read_rom, /* 0XXX, 1XXX, 2XXX, 3XXX */
|
|
read_mbc_rom, read_mbc_rom, read_mbc_rom, read_mbc_rom, /* 4XXX, 5XXX, 6XXX, 7XXX */
|
|
read_vram, read_vram, /* 8XXX, 9XXX */
|
|
read_mbc_ram, read_mbc_ram, /* AXXX, BXXX */
|
|
read_ram, read_banked_ram, /* CXXX, DXXX */
|
|
read_ram, read_high_memory, /* EXXX FXXX */
|
|
};
|
|
|
|
void GB_set_read_memory_callback(GB_gameboy_t *gb, GB_read_memory_callback_t callback)
|
|
{
|
|
gb->read_memory_callback = callback;
|
|
}
|
|
|
|
uint8_t GB_read_memory(GB_gameboy_t *gb, uint16_t addr)
|
|
{
|
|
if (gb->n_watchpoints) {
|
|
GB_debugger_test_read_watchpoint(gb, addr);
|
|
}
|
|
if (is_addr_in_dma_use(gb, addr)) {
|
|
addr = gb->dma_current_src;
|
|
}
|
|
uint8_t data = read_map[addr >> 12](gb, addr);
|
|
GB_apply_cheat(gb, addr, &data);
|
|
if (gb->read_memory_callback) {
|
|
data = gb->read_memory_callback(gb, addr, data);
|
|
}
|
|
return data;
|
|
}
|
|
|
|
static void write_mbc(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
switch (gb->cartridge_type->mbc_type) {
|
|
case GB_NO_MBC: return;
|
|
case GB_MBC1:
|
|
switch (addr & 0xF000) {
|
|
case 0x0000: case 0x1000: gb->mbc_ram_enable = (value & 0xF) == 0xA; break;
|
|
case 0x2000: case 0x3000: gb->mbc1.bank_low = value; break;
|
|
case 0x4000: case 0x5000: gb->mbc1.bank_high = value; break;
|
|
case 0x6000: case 0x7000: gb->mbc1.mode = value; break;
|
|
}
|
|
break;
|
|
case GB_MBC2:
|
|
switch (addr & 0x4100) {
|
|
case 0x0000: gb->mbc_ram_enable = (value & 0xF) == 0xA; break;
|
|
case 0x0100: gb->mbc2.rom_bank = value; break;
|
|
}
|
|
break;
|
|
case GB_MBC3:
|
|
switch (addr & 0xF000) {
|
|
case 0x0000: case 0x1000: gb->mbc_ram_enable = (value & 0xF) == 0xA; break;
|
|
case 0x2000: case 0x3000: gb->mbc3.rom_bank = value; break;
|
|
case 0x4000: case 0x5000:
|
|
gb->mbc3.ram_bank = value;
|
|
gb->mbc3_rtc_mapped = value & 8;
|
|
break;
|
|
case 0x6000: case 0x7000:
|
|
memcpy(&gb->rtc_latched, &gb->rtc_real, sizeof(gb->rtc_real));
|
|
break;
|
|
}
|
|
break;
|
|
case GB_MBC5:
|
|
switch (addr & 0xF000) {
|
|
case 0x0000: case 0x1000: gb->mbc_ram_enable = value == 0x0A; break;
|
|
case 0x2000: gb->mbc5.rom_bank_low = value; break;
|
|
case 0x3000: gb->mbc5.rom_bank_high = value; break;
|
|
case 0x4000: case 0x5000:
|
|
if (gb->cartridge_type->has_rumble) {
|
|
if (!!(value & 8) != !!gb->rumble_strength) {
|
|
gb->rumble_strength = gb->rumble_strength? 0 : 3;
|
|
}
|
|
value &= 7;
|
|
}
|
|
gb->mbc5.ram_bank = value;
|
|
gb->camera_registers_mapped = (value & 0x10) && gb->cartridge_type->mbc_subtype == GB_CAMERA;
|
|
break;
|
|
}
|
|
break;
|
|
case GB_HUC1:
|
|
switch (addr & 0xF000) {
|
|
case 0x0000: case 0x1000: gb->huc1.ir_mode = (value & 0xF) == 0xE; break;
|
|
case 0x2000: case 0x3000: gb->huc1.bank_low = value; break;
|
|
case 0x4000: case 0x5000: gb->huc1.bank_high = value; break;
|
|
case 0x6000: case 0x7000: gb->huc1.mode = value; break;
|
|
}
|
|
break;
|
|
case GB_HUC3:
|
|
switch (addr & 0xF000) {
|
|
case 0x0000: case 0x1000:
|
|
gb->huc3_mode = value & 0xF;
|
|
gb->mbc_ram_enable = gb->huc3_mode == 0xA;
|
|
break;
|
|
case 0x2000: case 0x3000: gb->huc3.rom_bank = value; break;
|
|
case 0x4000: case 0x5000: gb->huc3.ram_bank = value; break;
|
|
}
|
|
break;
|
|
case GB_TPP1:
|
|
switch (addr & 3) {
|
|
case 0:
|
|
gb->tpp1_rom_bank &= 0xFF00;
|
|
gb->tpp1_rom_bank |= value;
|
|
break;
|
|
case 1:
|
|
gb->tpp1_rom_bank &= 0xFF;
|
|
gb->tpp1_rom_bank |= value << 8;
|
|
break;
|
|
case 2:
|
|
gb->tpp1_ram_bank = value;
|
|
break;
|
|
case 3:
|
|
switch (value) {
|
|
case 0:
|
|
case 2:
|
|
case 3:
|
|
case 5:
|
|
gb->tpp1_mode = value;
|
|
break;
|
|
case 0x10:
|
|
memcpy(&gb->rtc_latched, &gb->rtc_real, sizeof(gb->rtc_real));
|
|
break;
|
|
case 0x11: {
|
|
memcpy(&gb->rtc_real, &gb->rtc_latched, sizeof(gb->rtc_real));
|
|
break;
|
|
}
|
|
case 0x14:
|
|
gb->tpp1_mr4 &= ~0x8;
|
|
break;
|
|
case 0x18:
|
|
gb->tpp1_mr4 &= ~0x4;
|
|
break;
|
|
case 0x19:
|
|
gb->tpp1_mr4 |= 0x4;
|
|
break;
|
|
|
|
case 0x20:
|
|
case 0x21:
|
|
case 0x22:
|
|
case 0x23:
|
|
gb->rumble_strength = value & 3;
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
GB_update_mbc_mappings(gb);
|
|
}
|
|
|
|
static void write_vram(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
if (gb->vram_write_blocked) {
|
|
//GB_log(gb, "Wrote %02x to %04x (VRAM) during mode 3\n", value, addr);
|
|
return;
|
|
}
|
|
/* TODO: not verified */
|
|
if (gb->display_state == 22 && GB_is_cgb(gb) && !gb->cgb_double_speed) {
|
|
if (addr & 0x1000) {
|
|
addr = gb->last_tile_index_address;
|
|
}
|
|
else if (gb->last_tile_data_address & 0x1000) {
|
|
/* TODO: This is case is more complicated then the rest and differ between revisions
|
|
It's probably affected by how VRAM is layed out, might be easier after a decap is done */
|
|
}
|
|
else {
|
|
addr = gb->last_tile_data_address;
|
|
}
|
|
}
|
|
gb->vram[(addr & 0x1FFF) + (gb->cgb_vram_bank? 0x2000 : 0)] = value;
|
|
}
|
|
|
|
static bool huc3_write(GB_gameboy_t *gb, uint8_t value)
|
|
{
|
|
switch (gb->huc3_mode) {
|
|
case 0xB: // RTC Write
|
|
switch (value >> 4) {
|
|
case 1:
|
|
if (gb->huc3_access_index < 3) {
|
|
gb->huc3_read = (gb->huc3_minutes >> (gb->huc3_access_index * 4)) & 0xF;
|
|
}
|
|
else if (gb->huc3_access_index < 7) {
|
|
gb->huc3_read = (gb->huc3_days >> ((gb->huc3_access_index - 3) * 4)) & 0xF;
|
|
}
|
|
else {
|
|
// GB_log(gb, "Attempting to read from unsupported HuC-3 register: %03x\n", gb->huc3_access_index);
|
|
}
|
|
gb->huc3_access_index++;
|
|
break;
|
|
case 2:
|
|
case 3:
|
|
if (gb->huc3_access_index < 3) {
|
|
gb->huc3_minutes &= ~(0xF << (gb->huc3_access_index * 4));
|
|
gb->huc3_minutes |= ((value & 0xF) << (gb->huc3_access_index * 4));
|
|
}
|
|
else if (gb->huc3_access_index < 7) {
|
|
gb->huc3_days &= ~(0xF << ((gb->huc3_access_index - 3) * 4));
|
|
gb->huc3_days |= ((value & 0xF) << ((gb->huc3_access_index - 3) * 4));
|
|
}
|
|
else if (gb->huc3_access_index >= 0x58 && gb->huc3_access_index <= 0x5a) {
|
|
gb->huc3_alarm_minutes &= ~(0xF << ((gb->huc3_access_index - 0x58) * 4));
|
|
gb->huc3_alarm_minutes |= ((value & 0xF) << ((gb->huc3_access_index - 0x58) * 4));
|
|
}
|
|
else if (gb->huc3_access_index >= 0x5b && gb->huc3_access_index <= 0x5e) {
|
|
gb->huc3_alarm_days &= ~(0xF << ((gb->huc3_access_index - 0x5b) * 4));
|
|
gb->huc3_alarm_days |= ((value & 0xF) << ((gb->huc3_access_index - 0x5b) * 4));
|
|
}
|
|
else if (gb->huc3_access_index == 0x5f) {
|
|
gb->huc3_alarm_enabled = value & 1;
|
|
}
|
|
else {
|
|
// GB_log(gb, "Attempting to write %x to unsupported HuC-3 register: %03x\n", value & 0xF, gb->huc3_access_index);
|
|
}
|
|
if ((value >> 4) == 3) {
|
|
gb->huc3_access_index++;
|
|
}
|
|
break;
|
|
case 4:
|
|
gb->huc3_access_index &= 0xF0;
|
|
gb->huc3_access_index |= value & 0xF;
|
|
break;
|
|
case 5:
|
|
gb->huc3_access_index &= 0x0F;
|
|
gb->huc3_access_index |= (value & 0xF) << 4;
|
|
break;
|
|
case 6:
|
|
gb->huc3_access_flags = (value & 0xF);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return true;
|
|
case 0xD: // RTC status
|
|
// Not sure what writes here mean, they're always 0xFE
|
|
return true;
|
|
case 0xE: { // IR mode
|
|
if (gb->cart_ir != (value & 1)) {
|
|
gb->cart_ir = value & 1;
|
|
if (gb->infrared_callback) {
|
|
gb->infrared_callback(gb, value & 1);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
case 0xC:
|
|
return true;
|
|
default:
|
|
return false;
|
|
case 0: // Disabled
|
|
case 0xA: // RAM
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static void write_mbc_ram(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
if (gb->cartridge_type->mbc_type == GB_HUC3) {
|
|
if (huc3_write(gb, value)) return;
|
|
}
|
|
|
|
if (gb->camera_registers_mapped) {
|
|
GB_camera_write_register(gb, addr, value);
|
|
return;
|
|
}
|
|
|
|
if (gb->cartridge_type->mbc_type == GB_TPP1) {
|
|
switch (gb->tpp1_mode) {
|
|
case 3:
|
|
break;
|
|
case 5:
|
|
gb->rtc_latched.data[(addr & 3) ^ 3] = value;
|
|
return;
|
|
default:
|
|
return;
|
|
}
|
|
}
|
|
|
|
if ((!gb->mbc_ram_enable)
|
|
&& gb->cartridge_type->mbc_type != GB_HUC1) return;
|
|
|
|
if (gb->cartridge_type->mbc_type == GB_HUC1 && gb->huc1.ir_mode) {
|
|
if (gb->cart_ir != (value & 1)) {
|
|
gb->cart_ir = value & 1;
|
|
if (gb->infrared_callback) {
|
|
gb->infrared_callback(gb, value & 1);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (gb->cartridge_type->has_rtc && gb->mbc3_rtc_mapped) {
|
|
if (gb->mbc_ram_bank <= 4) {
|
|
if (gb->mbc_ram_bank == 0) {
|
|
gb->rtc_cycles = 0;
|
|
}
|
|
gb->rtc_real.data[gb->mbc_ram_bank] = value;
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (!gb->mbc_ram || !gb->mbc_ram_size) {
|
|
return;
|
|
}
|
|
|
|
uint8_t effective_bank = gb->mbc_ram_bank;
|
|
if (gb->cartridge_type->mbc_type == GB_MBC3 && !gb->is_mbc30) {
|
|
if (gb->cartridge_type->has_rtc) {
|
|
if (effective_bank > 3) return;
|
|
}
|
|
effective_bank &= 0x3;
|
|
}
|
|
|
|
gb->mbc_ram[((addr & 0x1FFF) + effective_bank * 0x2000) & (gb->mbc_ram_size - 1)] = value;
|
|
}
|
|
|
|
static void write_ram(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
gb->ram[addr & 0x0FFF] = value;
|
|
}
|
|
|
|
static void write_banked_ram(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
gb->ram[(addr & 0x0FFF) + gb->cgb_ram_bank * 0x1000] = value;
|
|
}
|
|
|
|
static void write_high_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
if (addr < 0xFE00) {
|
|
GB_log(gb, "Wrote %02x to %04x (RAM Mirror)\n", value, addr);
|
|
write_banked_ram(gb, addr, value);
|
|
return;
|
|
}
|
|
|
|
if (addr < 0xFF00) {
|
|
if (gb->oam_write_blocked) {
|
|
GB_trigger_oam_bug(gb, addr);
|
|
return;
|
|
}
|
|
|
|
if ((gb->dma_steps_left && (gb->dma_cycles > 0 || gb->is_dma_restarting))) {
|
|
/* Todo: Does writing to OAM during DMA causes the OAM bug? */
|
|
return;
|
|
}
|
|
|
|
if (GB_is_cgb(gb)) {
|
|
if (addr < 0xFEA0) {
|
|
gb->oam[addr & 0xFF] = value;
|
|
}
|
|
switch (gb->model) {
|
|
case GB_MODEL_CGB_D:
|
|
if (addr > 0xfec0) {
|
|
addr |= 0xf0;
|
|
}
|
|
gb->extra_oam[addr - 0xfea0] = value;
|
|
break;
|
|
case GB_MODEL_CGB_C:
|
|
case GB_MODEL_CGB_B:
|
|
// case GB_MODEL_CGB_A:
|
|
case GB_MODEL_CGB_0:
|
|
addr &= ~0x18;
|
|
gb->extra_oam[addr - 0xfea0] = value;
|
|
break;
|
|
case GB_MODEL_DMG_B:
|
|
case GB_MODEL_MGB:
|
|
case GB_MODEL_SGB_NTSC:
|
|
case GB_MODEL_SGB_PAL:
|
|
case GB_MODEL_SGB_NTSC_NO_SFC:
|
|
case GB_MODEL_SGB_PAL_NO_SFC:
|
|
case GB_MODEL_SGB2:
|
|
case GB_MODEL_SGB2_NO_SFC:
|
|
case GB_MODEL_CGB_E:
|
|
case GB_MODEL_AGB:
|
|
break;
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (addr < 0xFEA0) {
|
|
if (gb->accessed_oam_row == 0xa0) {
|
|
for (unsigned i = 0; i < 8; i++) {
|
|
if ((i & 6) != (addr & 6)) {
|
|
gb->oam[(addr & 0xf8) + i] = gb->oam[0x98 + i];
|
|
}
|
|
else {
|
|
gb->oam[(addr & 0xf8) + i] = bitwise_glitch(gb->oam[(addr & 0xf8) + i], gb->oam[0x9c], gb->oam[0x98 + i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
gb->oam[addr & 0xFF] = value;
|
|
|
|
if (gb->accessed_oam_row == 0) {
|
|
gb->oam[0] = bitwise_glitch(gb->oam[0],
|
|
gb->oam[(addr & 0xf8)],
|
|
gb->oam[(addr & 0xfe)]);
|
|
gb->oam[1] = bitwise_glitch(gb->oam[1],
|
|
gb->oam[(addr & 0xf8) + 1],
|
|
gb->oam[(addr & 0xfe) | 1]);
|
|
for (unsigned i = 2; i < 8; i++) {
|
|
gb->oam[i] = gb->oam[(addr & 0xf8) + i];
|
|
}
|
|
}
|
|
}
|
|
else if (gb->accessed_oam_row == 0) {
|
|
gb->oam[addr & 0x7] = value;
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* Todo: Clean this code up: use a function table and move relevant code to display.c and timing.c
|
|
(APU read and writes are already at apu.c) */
|
|
if (addr < 0xFF80) {
|
|
/* Hardware registers */
|
|
switch (addr & 0xFF) {
|
|
case GB_IO_WY:
|
|
if (value == gb->current_line) {
|
|
gb->wy_triggered = true;
|
|
}
|
|
case GB_IO_WX:
|
|
case GB_IO_IF:
|
|
case GB_IO_SCX:
|
|
case GB_IO_SCY:
|
|
case GB_IO_BGP:
|
|
case GB_IO_OBP0:
|
|
case GB_IO_OBP1:
|
|
case GB_IO_SB:
|
|
case GB_IO_UNKNOWN2:
|
|
case GB_IO_UNKNOWN3:
|
|
case GB_IO_UNKNOWN4:
|
|
case GB_IO_UNKNOWN5:
|
|
gb->io_registers[addr & 0xFF] = value;
|
|
return;
|
|
case GB_IO_OPRI:
|
|
if ((!gb->boot_rom_finished || (gb->io_registers[GB_IO_KEY0] & 8)) && GB_is_cgb(gb)) {
|
|
gb->io_registers[addr & 0xFF] = value;
|
|
gb->object_priority = (value & 1) ? GB_OBJECT_PRIORITY_X : GB_OBJECT_PRIORITY_INDEX;
|
|
}
|
|
else if (gb->cgb_mode) {
|
|
gb->io_registers[addr & 0xFF] = value;
|
|
|
|
}
|
|
return;
|
|
case GB_IO_LYC:
|
|
|
|
/* TODO: Probably completely wrong in double speed mode */
|
|
|
|
/* TODO: This hack is disgusting */
|
|
if (gb->display_state == 29 && GB_is_cgb(gb)) {
|
|
gb->ly_for_comparison = 153;
|
|
GB_STAT_update(gb);
|
|
gb->ly_for_comparison = 0;
|
|
}
|
|
|
|
gb->io_registers[addr & 0xFF] = value;
|
|
|
|
/* These are the states when LY changes, let the display routine call GB_STAT_update for use
|
|
so it correctly handles T-cycle accurate LYC writes */
|
|
if (!GB_is_cgb(gb) || (
|
|
gb->display_state != 35 &&
|
|
gb->display_state != 26 &&
|
|
gb->display_state != 15 &&
|
|
gb->display_state != 16)) {
|
|
|
|
/* More hacks to make LYC write conflicts work */
|
|
if (gb->display_state == 14 && GB_is_cgb(gb)) {
|
|
gb->ly_for_comparison = 153;
|
|
GB_STAT_update(gb);
|
|
gb->ly_for_comparison = -1;
|
|
}
|
|
else {
|
|
GB_STAT_update(gb);
|
|
}
|
|
}
|
|
return;
|
|
|
|
case GB_IO_TIMA:
|
|
if (gb->tima_reload_state != GB_TIMA_RELOADED) {
|
|
gb->io_registers[GB_IO_TIMA] = value;
|
|
}
|
|
return;
|
|
|
|
case GB_IO_TMA:
|
|
gb->io_registers[GB_IO_TMA] = value;
|
|
if (gb->tima_reload_state != GB_TIMA_RUNNING) {
|
|
gb->io_registers[GB_IO_TIMA] = value;
|
|
}
|
|
return;
|
|
|
|
case GB_IO_TAC:
|
|
GB_emulate_timer_glitch(gb, gb->io_registers[GB_IO_TAC], value);
|
|
gb->io_registers[GB_IO_TAC] = value;
|
|
return;
|
|
|
|
|
|
case GB_IO_LCDC:
|
|
if ((value & 0x80) && !(gb->io_registers[GB_IO_LCDC] & 0x80)) {
|
|
gb->display_cycles = 0;
|
|
gb->display_state = 0;
|
|
gb->double_speed_alignment = 0;
|
|
if (GB_is_sgb(gb)) {
|
|
gb->frame_skip_state = GB_FRAMESKIP_SECOND_FRAME_RENDERED;
|
|
}
|
|
else if (gb->frame_skip_state == GB_FRAMESKIP_SECOND_FRAME_RENDERED) {
|
|
gb->frame_skip_state = GB_FRAMESKIP_LCD_TURNED_ON;
|
|
}
|
|
GB_timing_sync(gb);
|
|
}
|
|
else if (!(value & 0x80) && (gb->io_registers[GB_IO_LCDC] & 0x80)) {
|
|
/* Sync after turning off LCD */
|
|
gb->double_speed_alignment = 0;
|
|
GB_timing_sync(gb);
|
|
GB_lcd_off(gb);
|
|
}
|
|
/* Handle disabling objects while already fetching an object */
|
|
if ((gb->io_registers[GB_IO_LCDC] & 2) && !(value & 2)) {
|
|
if (gb->during_object_fetch) {
|
|
gb->cycles_for_line += gb->display_cycles;
|
|
gb->display_cycles = 0;
|
|
gb->object_fetch_aborted = true;
|
|
}
|
|
}
|
|
gb->io_registers[GB_IO_LCDC] = value;
|
|
if (!(value & 0x20)) {
|
|
gb->wx_triggered = false;
|
|
gb->wx166_glitch = false;
|
|
}
|
|
return;
|
|
|
|
case GB_IO_STAT:
|
|
/* Delete previous R/W bits */
|
|
gb->io_registers[GB_IO_STAT] &= 7;
|
|
/* Set them by value */
|
|
gb->io_registers[GB_IO_STAT] |= value & ~7;
|
|
/* Set unused bit to 1 */
|
|
gb->io_registers[GB_IO_STAT] |= 0x80;
|
|
|
|
GB_STAT_update(gb);
|
|
return;
|
|
|
|
case GB_IO_DIV:
|
|
/* Reset the div state machine */
|
|
gb->div_state = 0;
|
|
gb->div_cycles = 0;
|
|
return;
|
|
|
|
case GB_IO_JOYP:
|
|
if (gb->joyp_write_callback) {
|
|
gb->joyp_write_callback(gb, value);
|
|
GB_update_joyp(gb);
|
|
}
|
|
else if ((gb->io_registers[GB_IO_JOYP] & 0x30) != (value & 0x30)) {
|
|
GB_sgb_write(gb, value);
|
|
gb->io_registers[GB_IO_JOYP] = (value & 0xF0) | (gb->io_registers[GB_IO_JOYP] & 0x0F);
|
|
GB_update_joyp(gb);
|
|
}
|
|
return;
|
|
|
|
case GB_IO_BANK:
|
|
gb->boot_rom_finished = true;
|
|
return;
|
|
|
|
case GB_IO_KEY0:
|
|
if (GB_is_cgb(gb) && !gb->boot_rom_finished) {
|
|
gb->cgb_mode = !(value & 0xC); /* The real "contents" of this register aren't quite known yet. */
|
|
gb->io_registers[GB_IO_KEY0] = value;
|
|
}
|
|
return;
|
|
|
|
case GB_IO_DMA:
|
|
if (gb->dma_steps_left) {
|
|
/* This is not correct emulation, since we're not really delaying the second DMA.
|
|
One write that should have happened in the first DMA will not happen. However,
|
|
since that byte will be overwritten by the second DMA before it can actually be
|
|
read, it doesn't actually matter. */
|
|
gb->is_dma_restarting = true;
|
|
}
|
|
gb->dma_cycles = -7;
|
|
gb->dma_current_dest = 0;
|
|
gb->dma_current_src = value << 8;
|
|
gb->dma_steps_left = 0xa0;
|
|
gb->io_registers[GB_IO_DMA] = value;
|
|
return;
|
|
case GB_IO_SVBK:
|
|
if (gb->cgb_mode || (GB_is_cgb(gb) && !gb->boot_rom_finished)) {
|
|
gb->cgb_ram_bank = value & 0x7;
|
|
if (!gb->cgb_ram_bank) {
|
|
gb->cgb_ram_bank++;
|
|
}
|
|
}
|
|
return;
|
|
case GB_IO_VBK:
|
|
if (!gb->cgb_mode) {
|
|
return;
|
|
}
|
|
gb->cgb_vram_bank = value & 0x1;
|
|
return;
|
|
|
|
case GB_IO_BGPI:
|
|
case GB_IO_OBPI:
|
|
if (!GB_is_cgb(gb)) {
|
|
return;
|
|
}
|
|
gb->io_registers[addr & 0xFF] = value;
|
|
return;
|
|
case GB_IO_BGPD:
|
|
case GB_IO_OBPD:
|
|
if (!gb->cgb_mode && gb->boot_rom_finished) {
|
|
/* Todo: Due to the behavior of a broken Game & Watch Gallery 2 ROM on a real CGB. A proper test ROM
|
|
is required. */
|
|
return;
|
|
}
|
|
|
|
uint8_t index_reg = (addr & 0xFF) - 1;
|
|
if (gb->cgb_palettes_blocked) {
|
|
if (gb->io_registers[index_reg] & 0x80) {
|
|
gb->io_registers[index_reg]++;
|
|
gb->io_registers[index_reg] |= 0x80;
|
|
}
|
|
return;
|
|
}
|
|
((addr & 0xFF) == GB_IO_BGPD?
|
|
gb->background_palettes_data :
|
|
gb->sprite_palettes_data)[gb->io_registers[index_reg] & 0x3F] = value;
|
|
GB_palette_changed(gb, (addr & 0xFF) == GB_IO_BGPD, gb->io_registers[index_reg] & 0x3F);
|
|
if (gb->io_registers[index_reg] & 0x80) {
|
|
gb->io_registers[index_reg]++;
|
|
gb->io_registers[index_reg] |= 0x80;
|
|
}
|
|
return;
|
|
case GB_IO_KEY1:
|
|
if (!gb->cgb_mode) {
|
|
return;
|
|
}
|
|
gb->io_registers[GB_IO_KEY1] = value;
|
|
return;
|
|
case GB_IO_HDMA1:
|
|
if (gb->cgb_mode) {
|
|
gb->hdma_current_src &= 0xF0;
|
|
gb->hdma_current_src |= value << 8;
|
|
}
|
|
return;
|
|
case GB_IO_HDMA2:
|
|
if (gb->cgb_mode) {
|
|
gb->hdma_current_src &= 0xFF00;
|
|
gb->hdma_current_src |= value & 0xF0;
|
|
}
|
|
return;
|
|
case GB_IO_HDMA3:
|
|
if (gb->cgb_mode) {
|
|
gb->hdma_current_dest &= 0xF0;
|
|
gb->hdma_current_dest |= value << 8;
|
|
}
|
|
return;
|
|
case GB_IO_HDMA4:
|
|
if (gb->cgb_mode) {
|
|
gb->hdma_current_dest &= 0x1F00;
|
|
gb->hdma_current_dest |= value & 0xF0;
|
|
}
|
|
return;
|
|
case GB_IO_HDMA5:
|
|
if (!gb->cgb_mode) return;
|
|
if ((value & 0x80) == 0 && gb->hdma_on_hblank) {
|
|
gb->hdma_on_hblank = false;
|
|
return;
|
|
}
|
|
gb->hdma_on = (value & 0x80) == 0;
|
|
gb->hdma_on_hblank = (value & 0x80) != 0;
|
|
if (gb->hdma_on_hblank && (gb->io_registers[GB_IO_STAT] & 3) == 0) {
|
|
gb->hdma_on = true;
|
|
}
|
|
gb->io_registers[GB_IO_HDMA5] = value;
|
|
gb->hdma_steps_left = (gb->io_registers[GB_IO_HDMA5] & 0x7F) + 1;
|
|
/* Todo: Verify this. Gambatte's DMA tests require this. */
|
|
if (gb->hdma_current_dest + (gb->hdma_steps_left << 4) > 0xFFFF) {
|
|
gb->hdma_steps_left = (0x10000 - gb->hdma_current_dest) >> 4;
|
|
}
|
|
gb->hdma_cycles = -12;
|
|
return;
|
|
|
|
/* Todo: what happens when starting a transfer during a transfer?
|
|
What happens when starting a transfer during external clock?
|
|
*/
|
|
case GB_IO_SC:
|
|
if (!gb->cgb_mode) {
|
|
value |= 2;
|
|
}
|
|
gb->io_registers[GB_IO_SC] = value | (~0x83);
|
|
if ((value & 0x80) && (value & 0x1) ) {
|
|
gb->serial_length = gb->cgb_mode && (value & 2)? 16 : 512;
|
|
gb->serial_count = 0;
|
|
/* Todo: This is probably incorrect for CGB's faster clock mode. */
|
|
gb->serial_cycles &= 0xFF;
|
|
if (gb->serial_transfer_bit_start_callback) {
|
|
gb->serial_transfer_bit_start_callback(gb, gb->io_registers[GB_IO_SB] & 0x80);
|
|
}
|
|
}
|
|
else {
|
|
gb->serial_length = 0;
|
|
}
|
|
return;
|
|
|
|
case GB_IO_RP: {
|
|
if (!GB_is_cgb(gb)) {
|
|
return;
|
|
}
|
|
if ((gb->io_registers[GB_IO_RP] ^ value) & 1) {
|
|
if (gb->infrared_callback) {
|
|
gb->infrared_callback(gb, value & 1);
|
|
}
|
|
}
|
|
gb->io_registers[GB_IO_RP] = value;
|
|
|
|
return;
|
|
}
|
|
|
|
default:
|
|
if ((addr & 0xFF) >= GB_IO_NR10 && (addr & 0xFF) <= GB_IO_WAV_END) {
|
|
GB_apu_write(gb, addr & 0xFF, value);
|
|
return;
|
|
}
|
|
GB_log(gb, "Wrote %02x to %04x (HW Register)\n", value, addr);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (addr == 0xFFFF) {
|
|
/* Interrupt mask */
|
|
gb->interrupt_enable = value;
|
|
return;
|
|
}
|
|
|
|
/* HRAM */
|
|
gb->hram[addr - 0xFF80] = value;
|
|
}
|
|
|
|
|
|
|
|
static GB_write_function_t * const write_map[] =
|
|
{
|
|
write_mbc, write_mbc, write_mbc, write_mbc, /* 0XXX, 1XXX, 2XXX, 3XXX */
|
|
write_mbc, write_mbc, write_mbc, write_mbc, /* 4XXX, 5XXX, 6XXX, 7XXX */
|
|
write_vram, write_vram, /* 8XXX, 9XXX */
|
|
write_mbc_ram, write_mbc_ram, /* AXXX, BXXX */
|
|
write_ram, write_banked_ram, /* CXXX, DXXX */
|
|
write_ram, write_high_memory, /* EXXX FXXX */
|
|
};
|
|
|
|
void GB_write_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
|
{
|
|
if (gb->n_watchpoints) {
|
|
GB_debugger_test_write_watchpoint(gb, addr, value);
|
|
}
|
|
if (is_addr_in_dma_use(gb, addr)) {
|
|
/* Todo: What should happen? Will this affect DMA? Will data be written? What and where? */
|
|
return;
|
|
}
|
|
write_map[addr >> 12](gb, addr, value);
|
|
}
|
|
|
|
void GB_dma_run(GB_gameboy_t *gb)
|
|
{
|
|
while (gb->dma_cycles >= 4 && gb->dma_steps_left) {
|
|
/* Todo: measure this value */
|
|
gb->dma_cycles -= 4;
|
|
gb->dma_steps_left--;
|
|
|
|
if (gb->dma_current_src < 0xe000) {
|
|
gb->oam[gb->dma_current_dest++] = GB_read_memory(gb, gb->dma_current_src);
|
|
}
|
|
else {
|
|
/* Todo: Not correct on the CGB */
|
|
gb->oam[gb->dma_current_dest++] = GB_read_memory(gb, gb->dma_current_src & ~0x2000);
|
|
}
|
|
|
|
/* dma_current_src must be the correct value during GB_read_memory */
|
|
gb->dma_current_src++;
|
|
if (!gb->dma_steps_left) {
|
|
gb->is_dma_restarting = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
void GB_hdma_run(GB_gameboy_t *gb)
|
|
{
|
|
if (!gb->hdma_on) return;
|
|
|
|
while (gb->hdma_cycles >= 0x4) {
|
|
gb->hdma_cycles -= 0x4;
|
|
|
|
GB_write_memory(gb, 0x8000 | (gb->hdma_current_dest++ & 0x1FFF), GB_read_memory(gb, (gb->hdma_current_src++)));
|
|
|
|
if ((gb->hdma_current_dest & 0xf) == 0) {
|
|
if (--gb->hdma_steps_left == 0) {
|
|
gb->hdma_on = false;
|
|
gb->hdma_on_hblank = false;
|
|
gb->hdma_starting = false;
|
|
gb->io_registers[GB_IO_HDMA5] &= 0x7F;
|
|
break;
|
|
}
|
|
if (gb->hdma_on_hblank) {
|
|
gb->hdma_on = false;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|