@@ -11,6 +11,7 @@ file(GLOB ARM_SRC ${CMAKE_SOURCE_DIR}/src/arm/*.c)
 file(GLOB GBA_SRC ${CMAKE_SOURCE_DIR}/src/gba/*.c)
 file(GLOB UTIL_SRC ${CMAKE_SOURCE_DIR}/src/util/*.[cS])
 file(GLOB RENDERER_SRC ${CMAKE_SOURCE_DIR}/src/gba/renderers/video-software.c)
+set(UTIL_SRC ${UTIL_SRC};${CMAKE_SOURCE_DIR}/src/platform/commandline.c)
 source_group("ARM core" FILES ${ARM_SRC})
 source_group("GBA board" FILES ${GBA_SRC} ${RENDERER_SRC})
 source_group("Utilities" FILES ${UTIL_SRC})
@@ -39,6 +40,7 @@
 set(DEBUGGER_SRC "${CMAKE_SOURCE_DIR}/src/debugger/debugger.c;${CMAKE_SOURCE_DIR}/src/debugger/memory-debugger.c")
 
 if(USE_CLI_DEBUGGER)
+	add_definitions(-DUSE_CLI_DEBUGGER)
 	set(DEBUGGER_SRC "${DEBUGGER_SRC};${CMAKE_SOURCE_DIR}/src/debugger/cli-debugger.c")
 	set(DEBUGGER_LIB "edit")
 else()

@@ -164,6 +164,15 @@
 	return 0;
 }
 
+void GBAMapOptionsToContext(struct StartupOptions* opts, struct GBAThread* threadContext) {
+	threadContext->fd = opts->fd;
+	threadContext->fname = opts->fname;
+	threadContext->biosFd = opts->biosFd;
+	threadContext->frameskip = opts->frameskip;
+	threadContext->rewindBufferCapacity = opts->rewindBufferCapacity;
+	threadContext->rewindBufferInterval = opts->rewindBufferInterval;
+}
+
 int GBAThreadStart(struct GBAThread* threadContext) {
 	// TODO: error check
 	threadContext->activeKeys = 0;

@@ -6,6 +6,7 @@
 #include "gba.h"
 
 #include "util/threading.h"
+#include "platform/commandline.h"
 
 struct GBAThread;
 typedef void (*ThreadCallback)(struct GBAThread* threadContext);
@@ -71,6 +72,8 @@ int rewindBufferNext;
 	struct GBASerializedState** rewindBuffer;
 	int rewindBufferWriteOffset;
 };
+
+void GBAMapOptionsToContext(struct StartupOptions*, struct GBAThread*);
 
 int GBAThreadStart(struct GBAThread* threadContext);
 int GBAThreadHasStarted(struct GBAThread* threadContext);

@@ -0,0 +1,56 @@
+#include "commandline.h"
+
+#include <fcntl.h>
+#include <getopt.h>
+
+static const char* _defaultFilename = "test.rom";
+
+static const struct option _options[] = {
+	{ "bios", 1, 0, 'b' },
+	{ "gdb", 1, 0, 'g' },
+	{ 0, 0, 0, 0 }
+};
+
+int parseCommandArgs(struct StartupOptions* opts, int argc, char* const* argv) {
+	memset(opts, 0, sizeof(*opts));
+	opts->fd = -1;
+	opts->biosFd = -1;
+	opts->width = 240;
+	opts->height = 160;
+	opts->fullscreen = 0;
+
+	int ch;
+	while ((ch = getopt_long(argc, argv, "b:dfg", _options, 0)) != -1) {
+		switch (ch) {
+		case 'b':
+			opts->biosFd = open(optarg, O_RDONLY);
+			break;
+#ifdef USE_CLI_DEBUGGER
+		case 'd':
+			opts->debuggerType = DEBUGGER_CLI;
+			break;
+#endif
+		case 'f':
+			opts->fullscreen = 1;
+			break;
+#ifdef USE_GDB_STUB
+		case 'g':
+			opts->debuggerType = DEBUGGER_GDB;
+			break;
+#endif
+		}
+	}
+	argc -= optind;
+	argv += optind;
+	if (argc) {
+		opts->fname = argv[0];
+	} else {
+		opts->fname = _defaultFilename;
+	}
+	opts->fd = open(opts->fname, O_RDONLY);
+	return 1;
+}
+
+void usage(const char* arg0) {
+	printf("%s: bad arguments\n", arg0);
+}

@@ -0,0 +1,36 @@
+#ifndef COMMAND_LINE_H
+#define COMMAND_LINE_H
+
+#include "common.h"
+
+enum DebuggerType {
+	DEBUGGER_NONE = 0,
+#ifdef USE_CLI_DEBUGGER
+	DEBUGGER_CLI,
+#endif
+#ifdef USE_GDB_STUB
+	DEBUGGER_GDB,
+#endif
+	DEBUGGER_MAX
+};
+
+struct StartupOptions {
+	int fd;
+	const char* fname;
+	int biosFd;
+	int frameskip;
+	int rewindBufferCapacity;
+	int rewindBufferInterval;
+
+	int width;
+	int height;
+	int fullscreen;
+
+	enum DebuggerType debuggerType;
+	int debugAtStart;
+};
+
+int parseCommandArgs(struct StartupOptions* opts, int argc, char* const* argv);
+void usage(const char* arg0);
+
+#endif

@@ -1,9 +1,17 @@
+#ifdef USE_CLI_DEBUGGER
 #include "debugger/cli-debugger.h"
+#endif
+
+#ifdef USE_GDB_STUB
+#include "debugger/gdb-stub.h"
+#endif
+
 #include "gba-thread.h"
 #include "gba.h"
 #include "sdl-audio.h"
 #include "sdl-events.h"
 #include "renderers/video-software.h"
+#include "platform/commandline.h"
 
 #include <SDL.h>
 #ifdef __APPLE__
@@ -12,11 +20,9 @@ #else
 #include <GL/gl.h>
 #endif
 
-#include <fcntl.h>
 #include <errno.h>
 #include <signal.h>
 #include <sys/time.h>
-#include <unistd.h>
 
 struct GLSoftwareRenderer {
 	struct GBAVideoSoftwareRenderer d;
@@ -52,48 +58,73 @@ 0, 1
 };
 
 int main(int argc, char** argv) {
-	const char* fname = "test.rom";
-	if (argc > 1) {
-		fname = argv[1];
-	}
-	int fd = open(fname, O_RDONLY);
-	if (fd < 0) {
-		return 1;
-	}
-
 	struct GLSoftwareRenderer renderer;
 	GBAVideoSoftwareRendererCreate(&renderer.d);
 
-	renderer.viewportWidth = 240;
-	renderer.viewportHeight = 160;
+	struct StartupOptions opts;
+	if (!parseCommandArgs(&opts, argc, argv)) {
+		usage(argv[0]);
+		return 1;
+	}
+
+	renderer.viewportWidth = opts.width;
+	renderer.viewportHeight = opts.height;
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+	renderer.events.fullscreen = opts.fullscreen;
+#endif
 
 	if (!_GBASDLInit(&renderer)) {
 		return 1;
 	}
 
-	struct CLIDebugger debugger;
-	CLIDebuggerCreate(&debugger);
+	union {
+		struct ARMDebugger d;
+#ifdef USE_CLI_DEBUGGER
+		struct CLIDebugger cli;
+#endif
+#ifdef USE_GDB_STUB
+		struct GDBStub gdb;
+#endif
+	} debugger;
+
 	struct GBAThread context = {
-		.fd = fd,
-		.biosFd = -1,
-		.fname = fname,
 		.debugger = &debugger.d,
 		.renderer = &renderer.d.d,
-		.frameskip = 0,
+		.startCallback = _GBASDLStart,
+		.cleanCallback = _GBASDLClean,
 		.sync.videoFrameWait = 0,
 		.sync.audioWait = 1,
-		.startCallback = _GBASDLStart,
-		.cleanCallback = _GBASDLClean,
-		.userData = &renderer,
-		.rewindBufferCapacity = 10,
-		.rewindBufferInterval = 30
+		.userData = &renderer
 	};
+
+	switch (opts.debuggerType) {
+#ifdef USE_CLI_DEBUGGER
+	case DEBUGGER_CLI:
+		CLIDebuggerCreate(&debugger.cli);
+		break;
+#endif
+#ifdef USE_GDB_STUB
+	case DEBUGGER_GDB:
+		GDBStubCreate(&debugger.gdb);
+		break;
+#endif
+	case DEBUGGER_NONE:
+	case DEBUGGER_MAX:
+		context.debugger = 0;
+		break;
+	}
+
+	GBAMapOptionsToContext(&opts, &context);
+
 	GBAThreadStart(&context);
 
 	_GBASDLRunloop(&context, &renderer);
 
 	GBAThreadJoin(&context);
-	close(fd);
+	close(opts.fd);
+	if (opts.biosFd >= 0) {
+		close(opts.biosFd);
+	}
 
 	_GBASDLDeinit(&renderer);
 
@@ -129,7 +160,7 @@ SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
 #endif
 
 #if SDL_VERSION_ATLEAST(2, 0, 0)
-	renderer->window = SDL_CreateWindow("GBAc", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, renderer->viewportWidth, renderer->viewportHeight, SDL_WINDOW_OPENGL);
+	renderer->window = SDL_CreateWindow("GBAc", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, renderer->viewportWidth, renderer->viewportHeight, SDL_WINDOW_OPENGL | (SDL_WINDOW_FULLSCREEN_DESKTOP * renderer->events.fullscreen));
 	SDL_GL_CreateContext(renderer->window);
 	SDL_GetWindowSize(renderer->window, &renderer->viewportWidth, &renderer->viewportHeight);
 	renderer->events.window = renderer->window;