Stabilizing API: New joypad, debugger and reset APIs; internal APIs and direct struct access are no longer available without defining GB_INTERNAL. The SDL port uses the new “public” APIs, as well as most of the non-debug Cocoa code.

Cocoa/Document.m

@@ -1,16 +1,13 @@
+#define GB_INTERNAL // Todo: several debugging functions access the GB struct directly
 #include <AVFoundation/AVFoundation.h>
 #include <CoreAudio/CoreAudio.h>
 #include "GBAudioClient.h"
 #include "Document.h"
 #include "AppDelegate.h"
-#include "gb.h"
-#include "debugger.h"
-#include "memory.h"
-#include "camera.h"
-#include "display.h"
 #include "HexFiend/HexFiend.h"
 #include "GBMemoryByteArray.h"
 #include "GBWarningPopover.h"
+#include "gb.h"
 
 /* Todo: The general Objective-C coding style conflicts with SameBoy's. This file needs a cleanup. */
 /* Todo: Split into category files! This is so messy!!! */
@@ -61,25 +58,25 @@
 
 static void vblank(GB_gameboy_t *gb)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     [self vblank];
 }
 
 static void consoleLog(GB_gameboy_t *gb, const char *string, GB_log_attributes attributes)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     [self log:string withAttributes: attributes];
 }
 
 static char *consoleInput(GB_gameboy_t *gb)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     return strdup([self getDebuggerInput]);
 }
 
 static char *asyncConsoleInput(GB_gameboy_t *gb)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     const char *ret = [self getAsyncDebuggerInput];
     return ret? strdup(ret) : NULL;
 }
@@ -91,20 +88,20 @@ static uint32_t rgbEncode(GB_gameboy_t *gb, uint8_t r, uint8_t g, uint8_t b)
 
 static void cameraRequestUpdate(GB_gameboy_t *gb)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     [self cameraRequestUpdate];
 }
 
 static uint8_t cameraGetPixel(GB_gameboy_t *gb, uint8_t x, uint8_t y)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     return [self cameraGetPixelAtX:x andY:y];
 }
 
 static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
                        uint8_t top_margin, uint8_t bottom_margin, uint8_t exposure)
 {
-    Document *self = (__bridge Document *)(gb->user_data);
+    Document *self = (__bridge Document *)GB_get_user_data(gb);
     [self printImage:image height:height topMargin:top_margin bottomMargin:bottom_margin exposure:exposure];
 }
 
@@ -138,12 +135,11 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     GB_init_cgb(&gb);
     [self initCommon];
     GB_load_boot_rom(&gb, [[[NSBundle mainBundle] pathForResource:@"cgb_boot" ofType:@"bin"] UTF8String]);
-
 }
 
 - (void) initCommon
 {
-    gb.user_data = (__bridge void *)(self);
+    GB_set_user_data(&gb, (__bridge void *)(self));
     GB_set_vblank_callback(&gb, (GB_vblank_callback_t) vblank);
     GB_set_log_callback(&gb, (GB_log_callback_t) consoleLog);
     GB_set_input_callback(&gb, (GB_input_callback_t) consoleInput);
@@ -151,13 +147,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     GB_set_rgb_encode_callback(&gb, rgbEncode);
     GB_set_camera_get_pixel_callback(&gb, cameraGetPixel);
     GB_set_camera_update_request_callback(&gb, cameraRequestUpdate);
-    NSString *rom_warnings = [self captureOutputForBlock:^{
+    [self loadROM];
-        [self loadROM];
-    }];
-    if (rom_warnings && !rom_warning_issued) {
-        rom_warning_issued = true;
-        [GBWarningPopover popoverWithContents:rom_warnings onWindow:self.mainWindow];
-    }
 }
 
 - (void) vblank
@@ -203,52 +193,37 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
 - (void) stop
 {
     if (!running) return;
-    gb.debug_disable = true;
+    GB_debugger_set_disabled(&gb, true);
-    if (gb.debug_stopped) {
+    if (GB_debugger_is_stopped(&gb)) {
         gb.debug_stopped = false;
         [self consoleInput:nil];
     }
     stopping = true;
     running = false;
     while (stopping);
-    gb.debug_disable = false;
+    GB_debugger_set_disabled(&gb, false);
 }
 
 - (IBAction)reset:(id)sender
 {
-    bool was_cgb = gb.is_cgb;
     [self stop];
 
-    /* Back up user's breakpoints/watchpoints */
+    if ([sender tag] == 0) {
-    typeof(gb.breakpoints) breakpoints = gb.breakpoints;
+        GB_reset(&gb);
-    typeof(gb.n_breakpoints) n_breakpoints = gb.n_breakpoints;
-    typeof(gb.watchpoints) watchpoints = gb.watchpoints;
-    typeof(gb.n_watchpoints) n_watchpoints = gb.n_watchpoints;
-
-    /* Reset them so they're not freed*/
-    gb.watchpoints = NULL;
-    gb.breakpoints = NULL;
-    gb.n_watchpoints = gb.n_breakpoints = 0;
-    
-    GB_free(&gb);
-    if (([sender tag] == 0 && was_cgb) || [sender tag] == 2) {
-        [self initCGB];
     }
     else {
-        [self initDMG];
+        GB_switch_model_and_reset(&gb, [sender tag] == 2);
+        GB_load_boot_rom(&gb, [[[NSBundle mainBundle] pathForResource:[sender tag] == 2? @"cgb_boot" : @"dmg_boot" ofType:@"bin"] UTF8String]);
     }
 
-    /* Restore backpoints/watchpoints */
-    gb.breakpoints = breakpoints;
-    gb.n_breakpoints = n_breakpoints;
-    gb.watchpoints = watchpoints;
-    gb.n_watchpoints = n_watchpoints;
-
     if ([sender tag] != 0) {
         /* User explictly selected a model, save the preference */
-        [[NSUserDefaults standardUserDefaults] setBool:!gb.is_cgb forKey:@"EmulateDMG"];
+        [[NSUserDefaults standardUserDefaults] setBool:[sender tag] == 1 forKey:@"EmulateDMG"];
     }
-    [self readFromFile:self.fileName ofType:@"gb"];
+    
+    /* Reload the ROM, SAV and SYM files */
+    [self loadROM];
+
     [self start];
 
     if (hex_controller) {
@@ -380,10 +355,16 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
 
 - (void) loadROM
 {
-    GB_load_rom(&gb, [self.fileName UTF8String]);
+    NSString *rom_warnings = [self captureOutputForBlock:^{
-    GB_load_battery(&gb, [[[self.fileName stringByDeletingPathExtension] stringByAppendingPathExtension:@"sav"] UTF8String]);
+        GB_load_rom(&gb, [self.fileName UTF8String]);
-    GB_debugger_load_symbol_file(&gb, [[[NSBundle mainBundle] pathForResource:@"registers" ofType:@"sym"] UTF8String]);
+        GB_load_battery(&gb, [[[self.fileName stringByDeletingPathExtension] stringByAppendingPathExtension:@"sav"] UTF8String]);
-    GB_debugger_load_symbol_file(&gb, [[[self.fileName stringByDeletingPathExtension] stringByAppendingPathExtension:@"sym"] UTF8String]);
+        GB_debugger_load_symbol_file(&gb, [[[NSBundle mainBundle] pathForResource:@"registers" ofType:@"sym"] UTF8String]);
+        GB_debugger_load_symbol_file(&gb, [[[self.fileName stringByDeletingPathExtension] stringByAppendingPathExtension:@"sym"] UTF8String]);
+    }];
+    if (rom_warnings && !rom_warning_issued) {
+        rom_warning_issued = true;
+        [GBWarningPopover popoverWithContents:rom_warnings onWindow:self.mainWindow];
+    }
 }
 
 - (void)close
@@ -398,7 +379,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
 - (IBAction) interrupt:(id)sender
 {
     [self log:"^C\n"];
-    gb.debug_stopped = true;
+    GB_debugger_break(&gb);
     if (!running) {
         [self start];
     }
@@ -428,8 +409,8 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
         [(NSMenuItem*)anItem setState:!self.audioClient.isPlaying];
     }
     else if ([anItem action] == @selector(togglePause:)) {
-        [(NSMenuItem*)anItem setState:(!running) || (gb.debug_stopped)];
+        [(NSMenuItem*)anItem setState:(!running) || (GB_debugger_is_stopped(&gb))];
-        return !gb.debug_stopped;
+        return !GB_debugger_is_stopped(&gb);
     }
     else if ([anItem action] == @selector(reset:) && anItem.tag != 0) {
         [(NSMenuItem*)anItem setState:(anItem.tag == 1 && !gb.is_cgb) || (anItem.tag == 2 && gb.is_cgb)];
@@ -653,7 +634,7 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
 - (void) performAtomicBlock: (void (^)())block
 {
     while (!GB_is_inited(&gb));
-    bool was_running = running && !gb.debug_stopped;
+    bool was_running = running && !GB_debugger_is_stopped(&gb);
     if (was_running) {
         [self stop];
     }

Cocoa/GBMemoryByteArray.m

@@ -1,3 +1,4 @@
+#define GB_INTERNAL // Todo: Some memory accesses are being done using the struct directly
 #import "GBMemoryByteArray.h"
 #import "GBCompleteByteSlice.h"
 

Cocoa/GBView.m

@@ -172,11 +172,11 @@
             handled = true;
             switch (i) {
                 case GBTurbo:
-                    _gb->turbo = true;
+                    GB_set_turbo_mode(_gb, true);
                     break;
                     
                 default:
-                    _gb->keys[i] = true;
+                    GB_set_key_state(_gb, (GB_key_t)i, true);
                     break;
             }
         }
@@ -198,11 +198,11 @@
             handled = true;
             switch (i) {
                 case GBTurbo:
-                    _gb->turbo = false;
+                    GB_set_turbo_mode(_gb, false);
                     break;
 
                 default:
-                    _gb->keys[i] = false;
+                    GB_set_key_state(_gb, (GB_key_t)i, false);
                     break;
             }
         }

Core/apu.c

@@ -1,7 +1,6 @@
 #include <stdint.h>
 #include <math.h>
 #include <string.h>
-#include "apu.h"
 #include "gb.h"
 
 #undef max
@@ -443,4 +442,4 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
             }
             break;
     }
-}
+}

Core/apu.h

@@ -2,15 +2,11 @@
 #define apu_h
 #include <stdbool.h>
 #include <stdint.h>
-
+#include "gb_struct_def.h"
 /* Divides nicely and never overflows with 4 channels */
 #define MAX_CH_AMP 0x1E00
 #define CH_STEP (0x1E00/0xF)
 
-#include "save_struct.h"
-
-struct GB_gameboy_s;
-typedef struct GB_gameboy_s GB_gameboy_t;
 
 typedef struct
 {
@@ -59,10 +55,13 @@ typedef struct
 } GB_apu_t;
 
 void GB_apu_copy_buffer(GB_gameboy_t *gb, GB_sample_t *dest, unsigned int count);
+
+#ifdef GB_INTERNAL
 void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value);
 uint8_t GB_apu_read(GB_gameboy_t *gb, uint8_t reg);
 void GB_apu_get_samples_and_update_pcm_regs(GB_gameboy_t *gb, GB_sample_t *samples);
 void GB_apu_init(GB_gameboy_t *gb);
 void GB_apu_run(GB_gameboy_t *gb);
+#endif
 
 #endif /* apu_h */

Core/camera.c

@@ -1,4 +1,4 @@
-#include "camera.h"
+#include "gb.h"
 
 static int noise_seed = 0;
 
@@ -147,4 +147,4 @@ uint8_t GB_camera_read_register(GB_gameboy_t *gb, uint16_t addr)
         return gb->camera_registers[GB_CAMERA_SHOOT_AND_1D_FLAGS];
     }
     return 0;
-}
+}

Core/camera.h

@@ -1,6 +1,10 @@
 #ifndef camera_h
 #define camera_h
-#include "gb.h"
+#include <stdint.h>
+#include "gb_struct_def.h"
+
+typedef uint8_t (*GB_camera_get_pixel_callback_t)(GB_gameboy_t *gb, uint8_t x, uint8_t y);
+typedef void (*GB_camera_update_request_callback_t)(GB_gameboy_t *gb);
 
 enum {
     GB_CAMERA_SHOOT_AND_1D_FLAGS = 0,

Core/debugger.c

@@ -1,9 +1,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#include "debugger.h"
-#include "memory.h"
-#include "z80_cpu.h"
 #include "gb.h"
 
 typedef struct {
@@ -1792,3 +1789,18 @@ bool GB_debugger_evaluate(GB_gameboy_t *gb, const char *string, uint16_t *result
     }
     return error;
 }
+
+void GB_debugger_break(GB_gameboy_t *gb)
+{
+    gb->debug_stopped = true;
+}
+
+bool GB_debugger_is_stopped(GB_gameboy_t *gb)
+{
+    return gb->debug_stopped;
+}
+
+void GB_debugger_set_disabled(GB_gameboy_t *gb, bool disabled)
+{
+    gb->debug_disable = disabled;
+}

Core/debugger.h

@@ -1,15 +1,24 @@
 #ifndef debugger_h
 #define debugger_h
-#include "gb.h"
+#include <stdbool.h>
+#include <stdint.h>
+#include "gb_struct_def.h"
+#include "symbol_hash.h"
 
+#ifdef GB_INTERNAL
 void GB_debugger_run(GB_gameboy_t *gb);
 void GB_debugger_handle_async_commands(GB_gameboy_t *gb);
 void GB_debugger_call_hook(GB_gameboy_t *gb, uint16_t call_addr);
 void GB_debugger_ret_hook(GB_gameboy_t *gb);
 void GB_debugger_test_write_watchpoint(GB_gameboy_t *gb, uint16_t addr, uint8_t value);
 void GB_debugger_test_read_watchpoint(GB_gameboy_t *gb, uint16_t addr);
-void GB_debugger_load_symbol_file(GB_gameboy_t *gb, const char *path);
 const GB_bank_symbol_t *GB_debugger_find_symbol(GB_gameboy_t *gb, uint16_t addr);
+#endif
+
+void GB_debugger_load_symbol_file(GB_gameboy_t *gb, const char *path);
 const char *GB_debugger_name_for_address(GB_gameboy_t *gb, uint16_t addr);
 bool GB_debugger_evaluate(GB_gameboy_t *gb, const char *string, uint16_t *result, uint16_t *result_bank); /* result_bank is -1 if unused. */
+void GB_debugger_break(GB_gameboy_t *gb);
+bool GB_debugger_is_stopped(GB_gameboy_t *gb);
+void GB_debugger_set_disabled(GB_gameboy_t *gb, bool disabled);
 #endif /* debugger_h */

Core/display.c

@@ -5,7 +5,6 @@
 #include <assert.h>
 #include <string.h>
 #include "gb.h"
-#include "display.h"
 #ifdef _WIN32
 #define _WIN32_WINNT 0x0500
 #include <Windows.h>

Core/display.h

@@ -2,8 +2,10 @@
 #define display_h
 
 #include "gb.h"
+#ifdef GB_INTERNAL
 void GB_display_run(GB_gameboy_t *gb, uint8_t cycles);
 void GB_palette_changed(GB_gameboy_t *gb, bool background_palette, uint8_t index);
+#endif
 
 typedef enum {
     GB_PALETTE_NONE,
@@ -33,6 +35,6 @@ typedef struct {
 
 void GB_draw_tileset(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette_type, uint8_t palette_index);
 void GB_draw_tilemap(GB_gameboy_t *gb, uint32_t *dest, GB_palette_type_t palette_type, uint8_t palette_index, GB_map_type_t map_type, GB_tileset_type_t tileset_type);
-
 uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest);
+
 #endif /* display_h */

Core/gb.c

@@ -9,13 +9,6 @@
 #include <sys/time.h>
 #include <sys/select.h>
 #include "gb.h"
-#include "memory.h"
-#include "timing.h"
-#include "z80_cpu.h"
-#include "joypad.h"
-#include "display.h"
-#include "debugger.h"
-#include "mbc.h"
 
 void GB_attributed_logv(GB_gameboy_t *gb, GB_log_attributes attributes, const char *fmt, va_list args)
 {
@@ -92,54 +85,28 @@ static char *default_async_input_callback(GB_gameboy_t *gb)
 void GB_init(GB_gameboy_t *gb)
 {
     memset(gb, 0, sizeof(*gb));
-    gb->version = GB_STRUCT_VERSION;
     gb->ram = malloc(gb->ram_size = 0x2000);
-    memset(gb->ram, 0, gb->ram_size);
     gb->vram = malloc(gb->vram_size = 0x2000);
-    memset(gb->vram, 0, gb->vram_size);
 
-    gb->mbc_rom_bank = 1;
-    gb->last_rtc_second = time(NULL);
-    gb->last_vblank = clock();
-    gb->cgb_ram_bank = 1;
-
-    /* Todo: this bypasses the rgb encoder because it is not set yet. */
-    gb->sprite_palletes_rgb[4] = gb->sprite_palletes_rgb[0] = gb->background_palletes_rgb[0] = 0xFFFFFFFF;
-    gb->sprite_palletes_rgb[5] = gb->sprite_palletes_rgb[1] = gb->background_palletes_rgb[1] = 0xAAAAAAAA;
-    gb->sprite_palletes_rgb[6] = gb->sprite_palletes_rgb[2] = gb->background_palletes_rgb[2] = 0x55555555;
     gb->input_callback = default_input_callback;
     gb->async_input_callback = default_async_input_callback;
     gb->cartridge_type = &GB_cart_defs[0]; // Default cartridge type
-
+    
-    gb->io_registers[GB_IO_OBP0] = gb->io_registers[GB_IO_OBP1] = 0xFF;
+    GB_reset(gb);
-    gb->io_registers[GB_IO_JOYP] = 0xF;
-    gb->io_registers[GB_IO_SC] = 0x7E;
-    gb->magic = (uintptr_t)'SAME';
 }
 
 void GB_init_cgb(GB_gameboy_t *gb)
 {
     memset(gb, 0, sizeof(*gb));
-    gb->version = GB_STRUCT_VERSION;
     gb->ram = malloc(gb->ram_size = 0x2000 * 8);
-    memset(gb->ram, 0, gb->ram_size);
     gb->vram = malloc(gb->vram_size = 0x2000 * 2);
-    memset(gb->vram, 0, gb->vram_size);
     gb->is_cgb = true;
-    gb->cgb_mode = true;
 
-    gb->mbc_rom_bank = 1;
-    gb->last_rtc_second = time(NULL);
-    gb->last_vblank = clock();
-    gb->cgb_ram_bank = 1;
     gb->input_callback = default_input_callback;
     gb->async_input_callback = default_async_input_callback;
     gb->cartridge_type = &GB_cart_defs[0]; // Default cartridge type
 
-    gb->io_registers[GB_IO_OBP0] = gb->io_registers[GB_IO_OBP1] = 0xFF;
+    GB_reset(gb);
-    gb->io_registers[GB_IO_JOYP] = 0xF;
-    gb->io_registers[GB_IO_SC] = 0x7C;
-    gb->magic = 'SAME';
 }
 
 void GB_free(GB_gameboy_t *gb)
@@ -200,6 +167,9 @@ int GB_load_rom(GB_gameboy_t *gb, const char *path)
         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);
@@ -476,6 +446,16 @@ void GB_set_async_input_callback(GB_gameboy_t *gb, GB_input_callback_t callback)
 
 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_palletes_rgb[4] = gb->sprite_palletes_rgb[0] = gb->background_palletes_rgb[0] =
+        callback(gb, 0xFF, 0xFF, 0xFF);
+        gb->sprite_palletes_rgb[5] = gb->sprite_palletes_rgb[1] = gb->background_palletes_rgb[1] =
+        callback(gb, 0xAA, 0xAA, 0xAA);
+        gb->sprite_palletes_rgb[6] = gb->sprite_palletes_rgb[2] = gb->background_palletes_rgb[2] =
+        callback(gb, 0x55, 0x55, 0x55);
+        gb->sprite_palletes_rgb[7] = gb->sprite_palletes_rgb[3] = gb->background_palletes_rgb[3] =
+        callback(gb, 0, 0, 0);
+    }
     gb->rgb_encode_callback = callback;
 }
 
@@ -554,3 +534,84 @@ void GB_disconnect_serial(GB_gameboy_t *gb)
     /* 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';
+}
+
+void GB_set_turbo_mode(GB_gameboy_t *gb, bool on)
+{
+    gb->turbo = on;
+}
+
+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)
+{
+    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->last_vblank = clock();
+    gb->cgb_ram_bank = 1;
+    gb->io_registers[GB_IO_JOYP] = 0xF;
+    gb->io_registers[GB_IO_OBP0] = gb->io_registers[GB_IO_OBP1] = 0xFF;
+
+    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_SC] = 0x7C;
+    }
+    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_palletes_rgb[4] = gb->sprite_palletes_rgb[0] = gb->background_palletes_rgb[0] =
+                gb->rgb_encode_callback(gb, 0xFF, 0xFF, 0xFF);
+            gb->sprite_palletes_rgb[5] = gb->sprite_palletes_rgb[1] = gb->background_palletes_rgb[1] =
+                gb->rgb_encode_callback(gb, 0xAA, 0xAA, 0xAA);
+            gb->sprite_palletes_rgb[6] = gb->sprite_palletes_rgb[2] = gb->background_palletes_rgb[2] =
+                gb->rgb_encode_callback(gb, 0x55, 0x55, 0x55);
+            gb->sprite_palletes_rgb[7] = gb->sprite_palletes_rgb[3] = gb->background_palletes_rgb[3] =
+                gb->rgb_encode_callback(gb, 0, 0, 0);
+        }
+        
+        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_reset(gb);
+
+}

Core/gb.h

@@ -4,11 +4,21 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <time.h>
-#include "printer.h"
-#include "apu.h"
-#include "save_struct.h"
-#include "symbol_hash.h"
 
+#include "gb_struct_def.h"
+#include "save_struct.h"
+
+#include "apu.h"
+#include "camera.h"
+#include "debugger.h"
+#include "display.h"
+#include "joypad.h"
+#include "mbc.h"
+#include "memory.h"
+#include "printer.h"
+#include "timing.h"
+#include "z80_cpu.h"
+#include "symbol_hash.h"
 
 #define GB_STRUCT_VERSION 10
 
@@ -140,12 +150,6 @@ enum {
     GB_IO_UNKNOWN8   = 0x7F, // Unknown, write only
 };
 
-#define LCDC_PERIOD 70224
-#define CPU_FREQUENCY 0x400000
-#define DIV_CYCLES (0x100)
-#define INTERNAL_DIV_CYCLES (0x40000)
-#define FRAME_LENGTH 16742706 // in nanoseconds
-
 typedef enum {
     GB_LOG_BOLD = 1,
     GB_LOG_DASHED_UNDERLINE = 2,
@@ -153,40 +157,23 @@ typedef enum {
     GB_LOG_UNDERLINE_MASK =  GB_LOG_DASHED_UNDERLINE | GB_LOG_UNDERLINE
 } GB_log_attributes;
 
-struct GB_gameboy_s;
+#ifdef GB_INTERNAL
-typedef struct GB_gameboy_s GB_gameboy_t;
+#define LCDC_PERIOD 70224
+#define CPU_FREQUENCY 0x400000
+#define DIV_CYCLES (0x100)
+#define INTERNAL_DIV_CYCLES (0x40000)
+#define FRAME_LENGTH 16742706 // in nanoseconds
+#endif
+
 typedef void (*GB_vblank_callback_t)(GB_gameboy_t *gb);
 typedef void (*GB_log_callback_t)(GB_gameboy_t *gb, const char *string, GB_log_attributes attributes);
 typedef char *(*GB_input_callback_t)(GB_gameboy_t *gb);
 typedef uint32_t (*GB_rgb_encode_callback_t)(GB_gameboy_t *gb, uint8_t r, uint8_t g, uint8_t b);
 typedef void (*GB_infrared_callback_t)(GB_gameboy_t *gb, bool on, long cycles_since_last_update);
-typedef uint8_t (*GB_camera_get_pixel_callback_t)(GB_gameboy_t *gb, uint8_t x, uint8_t y);
-typedef void (*GB_camera_update_request_callback_t)(GB_gameboy_t *gb);
 typedef void (*GB_rumble_callback_t)(GB_gameboy_t *gb, bool rumble_on);
 typedef void (*GB_serial_transfer_start_callback_t)(GB_gameboy_t *gb, uint8_t byte_to_send);
 typedef uint8_t (*GB_serial_transfer_end_callback_t)(GB_gameboy_t *gb);
 
-
-typedef struct {
-    enum {
-        GB_NO_MBC,
-        GB_MBC1,
-        GB_MBC2,
-        GB_MBC3,
-        GB_MBC5,
-        GB_HUC1, /* Todo: HUC1 features are not emulated. Should be unified with the CGB IR sensor API. */
-        GB_HUC3,
-    } mbc_type;
-    enum {
-        GB_STANDARD_MBC,
-        GB_CAMERA,
-    } mbc_subtype;
-    bool has_ram;
-    bool has_battery;
-    bool has_rtc;
-    bool has_rumble;
-} GB_cartridge_t;
-
 typedef struct {
     bool state;
     long delay;
@@ -205,13 +192,11 @@ struct GB_watchpoint_s;
 /* Todo: We might want to typedef our own bool if this prevents SameBoy from working on specific platforms. */
 _Static_assert(sizeof(bool) == 1, "sizeof(bool) != 1");
 
-enum {
+#ifdef GB_INTERNAL
-    GB_TIMA_RUNNING = 0,
+struct GB_gameboy_s {
-    GB_TIMA_RELOADING = 1,
+#else
-    GB_TIMA_RELOADED = 2
+struct GB_gameboy_internal_s {
-};
+#endif
-
-typedef struct GB_gameboy_s {
     GB_SECTION(header,
         /* The magic makes sure a state file is:
             - Indeed a SameBoy state file.
@@ -389,95 +374,103 @@ typedef struct GB_gameboy_s {
     );
 
     /* Unsaved data. This includes all pointers, as well as everything that shouldn't be on a save state */
+    /* This data is reserved on reset and must come last in the struct */
+    GB_SECTION(unsaved,
+        /* ROM */
+        uint8_t *rom;
+        uint32_t rom_size;
+        const GB_cartridge_t *cartridge_type;
+        enum {
+            GB_STANDARD_MBC1_WIRING,
+            GB_MBC1M_WIRING,
+        } mbc1_wiring;
 
-    /* ROM */
+        /* Various RAMs */
-    uint8_t *rom;
+        uint8_t *ram;
-    uint32_t rom_size;
+        uint8_t *vram;
-    const GB_cartridge_t *cartridge_type;
+        uint8_t *mbc_ram;
-    enum {
-        GB_STANDARD_MBC1_WIRING,
-        GB_MBC1M_WIRING,
-    } mbc1_wiring;
 
-    /* Various RAMs */
+        /* I/O */
-    uint8_t *ram;
+        uint32_t *screen;
-    uint8_t *vram;
+        GB_sample_t *audio_buffer;
-    uint8_t *mbc_ram;
+        bool keys[GB_KEY_MAX];
 
-    /* I/O */
+        /* Audio Specific */
-    uint32_t *screen;
+        unsigned int buffer_size;
-    GB_sample_t *audio_buffer;
+        unsigned int sample_rate;
-    bool keys[8];
+        unsigned int audio_position;
+        bool audio_stream_started; // detects first copy request to minimize lag
+        volatile bool audio_copy_in_progress;
+        volatile bool apu_lock;
 
-    /* Audio Specific */
+        /* Callbacks */
-    unsigned int buffer_size;
+        void *user_data;
-    unsigned int sample_rate;
+        GB_log_callback_t log_callback;
-    unsigned int audio_position;
+        GB_input_callback_t input_callback;
-    bool audio_stream_started; // detects first copy request to minimize lag
+        GB_input_callback_t async_input_callback;
-    volatile bool audio_copy_in_progress;
+        GB_rgb_encode_callback_t rgb_encode_callback;
-    volatile bool apu_lock;
+        GB_vblank_callback_t vblank_callback;
+        GB_infrared_callback_t infrared_callback;
+        GB_camera_get_pixel_callback_t camera_get_pixel_callback;
+        GB_camera_update_request_callback_t camera_update_request_callback;
+        GB_rumble_callback_t rumble_callback;
+        GB_serial_transfer_start_callback_t serial_transfer_start_callback;
+        GB_serial_transfer_end_callback_t serial_transfer_end_callback;
+        /* IR */
+        long cycles_since_ir_change;
+        long cycles_since_input_ir_change;
+        GB_ir_queue_item_t ir_queue[GB_MAX_IR_QUEUE];
+        size_t ir_queue_length;
 
-    /* Callbacks */
+        /*** Debugger ***/
-    void *user_data;
+        volatile bool debug_stopped, debug_disable;
-    GB_log_callback_t log_callback;
+        bool debug_fin_command, debug_next_command;
-    GB_input_callback_t input_callback;
-    GB_input_callback_t async_input_callback;
-    GB_rgb_encode_callback_t rgb_encode_callback;
-    GB_vblank_callback_t vblank_callback;
-    GB_infrared_callback_t infrared_callback;
-    GB_camera_get_pixel_callback_t camera_get_pixel_callback;
-    GB_camera_update_request_callback_t camera_update_request_callback;
-    GB_rumble_callback_t rumble_callback;
-    GB_serial_transfer_start_callback_t serial_transfer_start_callback;
-    GB_serial_transfer_end_callback_t serial_transfer_end_callback;
-    /* IR */
-    long cycles_since_ir_change;
-    long cycles_since_input_ir_change;
-    GB_ir_queue_item_t ir_queue[GB_MAX_IR_QUEUE];
-    size_t ir_queue_length;
 
-    /*** Debugger ***/
+        /* Breakpoints */
-    volatile bool debug_stopped, debug_disable;
+        uint16_t n_breakpoints;
-    bool debug_fin_command, debug_next_command;
+        struct GB_breakpoint_s *breakpoints;
 
-    /* Breakpoints */
+        /* SLD (Todo: merge with backtrace) */
-    uint16_t n_breakpoints;
+        bool stack_leak_detection;
-    struct GB_breakpoint_s *breakpoints;
+        int debug_call_depth;
+        uint16_t sp_for_call_depth[0x200]; /* Should be much more than enough */
+        uint16_t addr_for_call_depth[0x200];
 
-    /* SLD (Todo: merge with backtrace) */
+        /* Backtrace */
-    bool stack_leak_detection;
+        unsigned int backtrace_size;
-    int debug_call_depth;
+        uint16_t backtrace_sps[0x200];
-    uint16_t sp_for_call_depth[0x200]; /* Should be much more than enough */
+        struct {
-    uint16_t addr_for_call_depth[0x200];
+            uint16_t bank;
+            uint16_t addr;
+        } backtrace_returns[0x200];
 
-    /* Backtrace */
+        /* Watchpoints */
-    unsigned int backtrace_size;
+        uint16_t n_watchpoints;
-    uint16_t backtrace_sps[0x200];
+        struct GB_watchpoint_s *watchpoints;
-    struct {
-        uint16_t bank;
-        uint16_t addr;
-    } backtrace_returns[0x200];
 
-    /* Watchpoints */
+        /* Symbol tables */
-    uint16_t n_watchpoints;
+        GB_symbol_map_t *bank_symbols[0x200];
-    struct GB_watchpoint_s *watchpoints;
+        GB_reversed_symbol_map_t reversed_symbol_map;
 
-    /* Symbol tables */
+        /* Ticks command */
-    GB_symbol_map_t *bank_symbols[0x200];
+        unsigned long debugger_ticks;
-    GB_reversed_symbol_map_t reversed_symbol_map;
 
-    /* Ticks command */
+        /* Misc */
-    unsigned long debugger_ticks;
+        bool turbo;
+        bool turbo_dont_skip;
+        bool disable_rendering;
+        uint32_t ram_size; // Different between CGB and DMG
+        uint8_t boot_rom[0x900];
+        bool vblank_just_occured; // For slow operations involving syscalls; these should only run once per vblank
+   );
+};
+    
+#ifndef GB_INTERNAL
+struct GB_gameboy_s {
+    char __internal[sizeof(struct GB_gameboy_internal_s)];
+};
+#endif
 
-    /* Misc */
-    bool turbo;
-    bool turbo_dont_skip;
-    bool disable_rendering;
-    uint32_t ram_size; // Different between CGB and DMG
-    uint8_t boot_rom[0x900];
-    bool vblank_just_occured; // For slow operations involving syscalls; these should only run once per vblank
-
-} GB_gameboy_t;
 
 #ifndef __printflike
 /* Missing from Linux headers. */
@@ -488,6 +481,8 @@ __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
 void GB_init(GB_gameboy_t *gb);
 void GB_init_cgb(GB_gameboy_t *gb);
 void GB_free(GB_gameboy_t *gb);
+void GB_reset(GB_gameboy_t *gb);
+void GB_switch_model_and_reset(GB_gameboy_t *gb, bool is_cgb);
 int GB_load_boot_rom(GB_gameboy_t *gb, const char *path);
 int GB_load_rom(GB_gameboy_t *gb, const char *path);
 int GB_save_battery(GB_gameboy_t *gb, const char *path);
@@ -519,8 +514,8 @@ void GB_serial_set_data(GB_gameboy_t *gb, uint8_t data);
 
 void GB_disconnect_serial(GB_gameboy_t *gb);
 
-static inline bool GB_is_inited(GB_gameboy_t *gb)
+bool GB_is_inited(GB_gameboy_t *gb);
-{
+void GB_set_turbo_mode(GB_gameboy_t *gb, bool on);
-    return gb->magic == 'SAME';
+void *GB_get_user_data(GB_gameboy_t *gb);
-}
+void GB_set_user_data(GB_gameboy_t *gb, void *data);
 #endif /* GB_h */

Core/gb_struct_def.h

@@ -0,0 +1,5 @@
+#ifndef gb_struct_def_h
+#define gb_struct_def_h
+struct GB_gameboy_s;
+typedef struct GB_gameboy_s GB_gameboy_t;
+#endif 

Core/joypad.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include "gb.h"
-#include "joypad.h"
+#include <assert.h>
 
 void GB_update_joyp(GB_gameboy_t *gb)
 {
@@ -54,4 +54,10 @@ void GB_update_joyp(GB_gameboy_t *gb)
         gb->io_registers[GB_IO_IF] |= 0x10;
     }
     gb->io_registers[GB_IO_JOYP] |= 0xC0; // No SGB support
-}
+}
+
+void GB_set_key_state(GB_gameboy_t *gb, GB_key_t index, bool pressed)
+{
+    assert(index >= 0 && index < GB_KEY_MAX);
+    gb->keys[index] = pressed;
+}

Core/joypad.h

@@ -1,8 +1,22 @@
 #ifndef joypad_h
 #define joypad_h
-#include "gb.h"
+#include "gb_struct_def.h"
 
+typedef enum {
+    GB_KEY_RIGHT,
+    GB_KEY_LEFT,
+    GB_KEY_UP,
+    GB_KEY_DOWN,
+    GB_KEY_A,
+    GB_KEY_B,
+    GB_KEY_SELECT,
+    GB_KEY_START,
+    GB_KEY_MAX
+} GB_key_t;
+
+void GB_set_key_state(GB_gameboy_t *gb, GB_key_t index, bool pressed);
+
+#ifdef GB_INTERNAL
 void GB_update_joyp(GB_gameboy_t *gb);
-void GB_update_keys_status(GB_gameboy_t *gb);
+#endif
-
 #endif /* joypad_h */

Core/mbc.h

@@ -1,8 +1,31 @@
 #ifndef MBC_h
 #define MBC_h
-#include "gb.h"
+#include "gb_struct_def.h"
 
+typedef struct {
+    enum {
+        GB_NO_MBC,
+        GB_MBC1,
+        GB_MBC2,
+        GB_MBC3,
+        GB_MBC5,
+        GB_HUC1, /* Todo: HUC1 features are not emulated. Should be unified with the CGB IR sensor API. */
+        GB_HUC3,
+    } mbc_type;
+    enum {
+        GB_STANDARD_MBC,
+        GB_CAMERA,
+    } mbc_subtype;
+    bool has_ram;
+    bool has_battery;
+    bool has_rtc;
+    bool has_rumble;
+} GB_cartridge_t;
+
+#ifdef GB_INTERNAL
 extern const GB_cartridge_t GB_cart_defs[256];
 void GB_update_mbc_mappings(GB_gameboy_t *gb);
 void GB_configure_cart(GB_gameboy_t *gb);
+#endif
+
 #endif /* MBC_h */

Core/memory.c

@@ -1,13 +1,6 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include "gb.h"
-#include "joypad.h"
-#include "display.h"
-#include "memory.h"
-#include "debugger.h"
-#include "mbc.h"
-#include "timing.h"
-#include "camera.h"
 
 typedef uint8_t GB_read_function_t(GB_gameboy_t *gb, uint16_t addr);
 typedef void GB_write_function_t(GB_gameboy_t *gb, uint16_t addr, uint8_t value);

Core/memory.h

@@ -4,7 +4,9 @@
 
 uint8_t GB_read_memory(GB_gameboy_t *gb, uint16_t addr);
 void GB_write_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value);
+#ifdef GB_INTERNAL
 void GB_dma_run(GB_gameboy_t *gb);
 void GB_hdma_run(GB_gameboy_t *gb);
+#endif
 
 #endif /* memory_h */

Core/printer.h

@@ -2,12 +2,10 @@
 #define printer_h
 #include <stdint.h>
 #include <stdbool.h>
-
+#include "gb_struct_def.h"
 #define GB_PRINTER_MAX_COMMAND_LENGTH 0x280
 #define GB_PRINTER_DATA_SIZE 0x280
 
-typedef struct GB_gameboy_s GB_gameboy_t;
-
 typedef void (*GB_print_image_callback_t)(GB_gameboy_t *gb,
                                           uint32_t *image,
                                           uint8_t height,
@@ -57,7 +55,5 @@ typedef struct
 } GB_printer_t;
 
 
-typedef struct GB_gameboy_s GB_gameboy_t;
-
 void GB_connect_printer(GB_gameboy_t *gb, GB_print_image_callback_t callback);
-#endif
+#endif

Core/symbol_hash.h

@@ -21,16 +21,17 @@ typedef struct {
     size_t n_symbols;
 } GB_symbol_map_t;
 
-GB_bank_symbol_t *GB_map_add_symbol(GB_symbol_map_t *map, uint16_t addr, const char *name);
-const GB_bank_symbol_t *GB_map_find_symbol(GB_symbol_map_t *map, uint16_t addr);
-GB_symbol_map_t *GB_map_alloc(void);
-void GB_map_free(GB_symbol_map_t *map);
-
 typedef struct {
     GB_symbol_t *buckets[0x400];
 } GB_reversed_symbol_map_t;
 
+#ifdef GB_INTERNAL
 void GB_reversed_map_add_symbol(GB_reversed_symbol_map_t *map, uint16_t bank, GB_bank_symbol_t *symbol);
 const GB_symbol_t *GB_reversed_map_find_symbol(GB_reversed_symbol_map_t *map, const char *name);
+GB_bank_symbol_t *GB_map_add_symbol(GB_symbol_map_t *map, uint16_t addr, const char *name);
+const GB_bank_symbol_t *GB_map_find_symbol(GB_symbol_map_t *map, uint16_t addr);
+GB_symbol_map_t *GB_map_alloc(void);
+void GB_map_free(GB_symbol_map_t *map);
+#endif
 
 #endif /* symbol_hash_h */

Core/timing.c

@@ -1,7 +1,4 @@
 #include "gb.h"
-#include "timing.h"
-#include "memory.h"
-#include "display.h"
 
 static void GB_ir_run(GB_gameboy_t *gb)
 {

Core/timing.h

@@ -2,8 +2,17 @@
 #define timing_h
 #include "gb.h"
 
+#ifdef GB_INTERNAL
 void GB_advance_cycles(GB_gameboy_t *gb, uint8_t cycles);
 void GB_set_internal_div_counter(GB_gameboy_t *gb, uint32_t value);
 void GB_rtc_run(GB_gameboy_t *gb);
 void GB_emulate_timer_glitch(GB_gameboy_t *gb, uint8_t old_tac, uint8_t new_tac);
+
+enum {
+    GB_TIMA_RUNNING = 0,
+    GB_TIMA_RELOADING = 1,
+    GB_TIMA_RELOADED = 2
+};
+#endif
+
 #endif /* timing_h */

Core/z80_cpu.c

@@ -1,9 +1,5 @@
 #include <stdio.h>
 #include <stdbool.h>
-#include "z80_cpu.h"
-#include "timing.h"
-#include "memory.h"
-#include "debugger.h"
 #include "gb.h"
 
 

Core/z80_cpu.h

@@ -1,7 +1,10 @@
 #ifndef z80_cpu_h
 #define z80_cpu_h
 #include "gb.h"
+
 void GB_cpu_disassemble(GB_gameboy_t *gb, uint16_t pc, uint16_t count);
+#ifdef GB_INTERNAL
 void GB_cpu_run(GB_gameboy_t *gb);
+#endif
 
 #endif /* z80_cpu_h */

Core/z80_disassembler.c

@@ -1,9 +1,6 @@
 #include <stdio.h>
 #include <stdbool.h>
-#include "z80_cpu.h"
-#include "memory.h"
 #include "gb.h"
-#include "debugger.h"
 
 
 typedef void GB_opcode_t(GB_gameboy_t *gb, uint8_t opcode, uint16_t *pc);

Makefile

@@ -135,6 +135,10 @@ $(OBJ)/%.dep: %
 
 # Compilation rules
 
+$(OBJ)/Core/%.c.o: Core/%.c
+	-@$(MKDIR) -p $(dir $@)
+	$(CC) $(CFLAGS) -DGB_INTERNAL -c $< -o $@
+
 $(OBJ)/%.c.o: %.c
 	-@$(MKDIR) -p $(dir $@)
 	$(CC) $(CFLAGS) -c $< -o $@

QuickLook/get_image_for_rom.c

@@ -1,3 +1,6 @@
+#define GB_INTERNAL // Todo: This file runs SameBoy in a special configuration
+                    // of the turbo mode, which is not available without direct
+                    // struct access
 #include <stdio.h>
 #include <stdbool.h>
 #include <unistd.h>
@@ -27,7 +30,7 @@ static void log_callback(GB_gameboy_t *gb, const char *string, GB_log_attributes
 static void vblank(GB_gameboy_t *gb)
 {
 
-    struct local_data *local_data = (struct local_data *)gb->user_data;
+    struct local_data *local_data = (struct local_data *)GB_get_user_data(gb);
 
     if (local_data->frames == LENGTH) {
         local_data->running = false;
@@ -66,7 +69,7 @@ int get_image_for_rom(const char *filename, const char *boot_path, uint32_t *out
         
     /* Run emulation */
     struct local_data local_data = {0,};
-    gb.user_data = &local_data;
+    GB_set_user_data(&gb, &local_data);
     local_data.running = true;
     local_data.frames = 0;
     gb.turbo = gb.turbo_dont_skip = gb.disable_rendering = true;

SDL/main.c

@@ -16,7 +16,6 @@
 #endif
 
 #include "gb.h"
-#include "debugger.h"
 
 static bool running = false;
 static char *filename;
@@ -38,34 +37,33 @@ static void GB_update_keys_status(GB_gameboy_t *gb)
                 running = false;
             case SDL_KEYDOWN:
             case SDL_KEYUP:
-                gb->stopped = false;
                 switch (event.key.keysym.sym) {
                     case SDLK_RIGHT:
-                        gb->keys[0] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_RIGHT, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_LEFT:
-                        gb->keys[1] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_LEFT, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_UP:
-                        gb->keys[2] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_UP, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_DOWN:
-                        gb->keys[3] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_DOWN, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_x:
-                        gb->keys[4] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_A, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_z:
-                        gb->keys[5] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_B, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_BACKSPACE:
-                        gb->keys[6] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_SELECT, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_RETURN:
-                        gb->keys[7] = event.type == SDL_KEYDOWN;
+                        GB_set_key_state(gb, GB_KEY_START, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_SPACE:
-                        gb->turbo = event.type == SDL_KEYDOWN;
+                        GB_set_turbo_mode(gb, event.type == SDL_KEYDOWN);
                         break;
                     case SDLK_LCTRL:
                     case SDLK_RCTRL:
@@ -85,7 +83,7 @@ static void GB_update_keys_status(GB_gameboy_t *gb)
                     case SDLK_c:
                         if (ctrl && event.type == SDL_KEYDOWN) {
                             ctrl = false;
-                            gb->debug_stopped = true;
+                            GB_debugger_break(gb);
 
                         }
                         break;
@@ -122,7 +120,7 @@ static void GB_update_keys_status(GB_gameboy_t *gb)
 
 static void vblank(GB_gameboy_t *gb)
 {
-    SDL_Surface *screen = gb->user_data;
+    SDL_Surface *screen = GB_get_user_data(gb);
     SDL_Flip(screen);
     GB_update_keys_status(gb);
 
@@ -189,10 +187,10 @@ static uint32_t rgb_encode(GB_gameboy_t *gb, uint8_t r, uint8_t g, uint8_t b)
 static void debugger_interrupt(int ignore)
 {
     /* ^C twice to exit */
-    if (gb.debug_stopped) {
+    if (GB_debugger_is_stopped(&gb)) {
         exit(0);
     }
-    gb.debug_stopped = true;
+    GB_debugger_break(&gb);
 }
 
 
@@ -280,7 +278,7 @@ usage:
     /* Configure Screen */
     SDL_LockSurface(screen);
     GB_set_vblank_callback(&gb, (GB_vblank_callback_t) vblank);
-    gb.user_data = screen;
+    GB_set_user_data(&gb, screen);
     GB_set_pixels_output(&gb, screen->pixels);
     GB_set_rgb_encode_callback(&gb, rgb_encode);
 

Tester/main.c

@@ -1,3 +1,6 @@
+// The tester requires low-level access to the GB struct to detect failures
+#define GB_INTERNAL
+
 #include <stdio.h>
 #include <stdbool.h>
 #include <unistd.h>