Doesn't affect other ports (same code should compile for all platforms). Lets you see error messages. No longer mentions crash (which was always a myth). Some things are supposed to be 32 bit, like the icon.

By the way, try typing "help" and pressing Enter to see normal colours.
Batch files work, internal DOS commands work, EXE and COM files give an error.

src/gui/render_scalers.cpp

@@ -173,7 +173,11 @@ ScalerLineBlock_t ScalerCache = {
 
 ScalerSimpleBlock_t ScaleNormal1x = {
 	"Normal",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	1,1,{
 {	Normal1x_8_8_L,		Normal1x_8_15_L ,	Normal1x_8_16_L ,	Normal1x_8_32_L },
 {	             0,		Normal1x_15_15_L,	Normal1x_15_16_L,	Normal1x_15_32_L},
@@ -190,7 +194,11 @@ ScalerSimpleBlock_t ScaleNormal1x = {
 
 ScalerSimpleBlock_t ScaleNormalDw = {
 	"Normal",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	2,1,{
 {	NormalDw_8_8_L,		NormalDw_8_15_L ,	NormalDw_8_16_L ,	NormalDw_8_32_L },
 {	             0,		NormalDw_15_15_L,	NormalDw_15_16_L,	NormalDw_15_32_L},
@@ -207,7 +215,11 @@ ScalerSimpleBlock_t ScaleNormalDw = {
 
 ScalerSimpleBlock_t ScaleNormalDh = {
 	"Normal",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	1,2,{
 {	NormalDh_8_8_L,		NormalDh_8_15_L ,	NormalDh_8_16_L ,	NormalDh_8_32_L },
 {	             0,		NormalDh_15_15_L,	NormalDh_15_16_L,	NormalDh_15_32_L},
@@ -224,7 +236,11 @@ ScalerSimpleBlock_t ScaleNormalDh = {
 
 ScalerSimpleBlock_t ScaleNormal2x = {
 	"Normal2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	2,2,{
 {	Normal2x_8_8_L,		Normal2x_8_15_L,	Normal2x_8_16_L,	Normal2x_8_32_L },
 {	             0,		Normal2x_15_15_L,	Normal2x_15_16_L,	Normal2x_15_32_L},
@@ -241,7 +257,11 @@ ScalerSimpleBlock_t ScaleNormal2x = {
 
 ScalerSimpleBlock_t ScaleNormal3x = {
 	"Normal3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	3,3,{
 {	Normal3x_8_8_L,		Normal3x_8_15_L ,	Normal3x_8_16_L ,	Normal3x_8_32_L },
 {	             0,		Normal3x_15_15_L,	Normal3x_15_16_L,	Normal3x_15_32_L},
@@ -259,7 +279,11 @@ ScalerSimpleBlock_t ScaleNormal3x = {
 #if RENDER_USE_ADVANCED_SCALERS>0
 ScalerSimpleBlock_t ScaleTV2x = {
 	"TV2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,{
 {	0,		TV2x_8_15_L ,	TV2x_8_16_L ,	TV2x_8_32_L },
 {	0,		TV2x_15_15_L,	TV2x_15_16_L,	TV2x_15_32_L},
@@ -276,7 +300,11 @@ ScalerSimpleBlock_t ScaleTV2x = {
 
 ScalerSimpleBlock_t ScaleTV3x = {
 	"TV3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	3,3,{
 {	0,		TV3x_8_15_L ,	TV3x_8_16_L ,	TV3x_8_32_L },
 {	0,		TV3x_15_15_L,	TV3x_15_16_L,	TV3x_15_32_L},
@@ -293,7 +321,11 @@ ScalerSimpleBlock_t ScaleTV3x = {
 
 ScalerSimpleBlock_t ScaleScan2x = {
 	"Scan2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,{
 {	0,		Scan2x_8_15_L ,	Scan2x_8_16_L ,	Scan2x_8_32_L },
 {	0,		Scan2x_15_15_L,	Scan2x_15_16_L,	Scan2x_15_32_L},
@@ -310,7 +342,11 @@ ScalerSimpleBlock_t ScaleScan2x = {
 
 ScalerSimpleBlock_t ScaleScan3x = {
 	"Scan3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	3,3,{
 {	0,		Scan3x_8_15_L ,	Scan3x_8_16_L ,	Scan3x_8_32_L },
 {	0,		Scan3x_15_15_L,	Scan3x_15_16_L,	Scan3x_15_32_L},
@@ -327,7 +363,11 @@ ScalerSimpleBlock_t ScaleScan3x = {
 
 ScalerSimpleBlock_t ScaleRGB2x = {
 	"RGB2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,{
 {	0,		RGB2x_8_15_L ,	RGB2x_8_16_L ,	RGB2x_8_32_L },
 {	0,		RGB2x_15_15_L,	RGB2x_15_16_L,	RGB2x_15_32_L},
@@ -344,7 +384,11 @@ ScalerSimpleBlock_t ScaleRGB2x = {
 
 ScalerSimpleBlock_t ScaleRGB3x = {
 	"RGB3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	3,3,{
 {	0,		RGB3x_8_15_L ,	RGB3x_8_16_L ,	RGB3x_8_32_L },
 {	0,		RGB3x_15_15_L,	RGB3x_15_16_L,	RGB3x_15_32_L},
@@ -366,7 +410,11 @@ ScalerSimpleBlock_t ScaleRGB3x = {
 #if RENDER_USE_ADVANCED_SCALERS>2
 ScalerComplexBlock_t ScaleAdvMame2x ={
 	"AdvMame2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	2,2,
 {	AdvMame2x_8_L,AdvMame2x_16_L,AdvMame2x_16_L,AdvMame2x_32_L},
 {	AdvMame2x_8_R,AdvMame2x_16_R,AdvMame2x_16_R,AdvMame2x_32_R}
@@ -374,7 +422,11 @@ ScalerComplexBlock_t ScaleAdvMame2x ={
 
 ScalerComplexBlock_t ScaleAdvMame3x = {
 	"AdvMame3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_8|GFX_CAN_15|GFX_CAN_16|GFX_CAN_32,
+#endif
 	3,3,
 {	AdvMame3x_8_L,AdvMame3x_16_L,AdvMame3x_16_L,AdvMame3x_32_L},
 {	AdvMame3x_8_R,AdvMame3x_16_R,AdvMame3x_16_R,AdvMame3x_32_R}
@@ -383,7 +435,11 @@ ScalerComplexBlock_t ScaleAdvMame3x = {
 /* These need specific 15bpp versions */
 ScalerComplexBlock_t ScaleHQ2x ={
 	"HQ2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,
 {	0,HQ2x_16_L,HQ2x_16_L,HQ2x_32_L},
 {	0,HQ2x_16_R,HQ2x_16_R,HQ2x_32_R}
@@ -391,7 +447,11 @@ ScalerComplexBlock_t ScaleHQ2x ={
 
 ScalerComplexBlock_t ScaleHQ3x ={
 	"HQ3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	3,3,
 {	0,HQ3x_16_L,HQ3x_16_L,HQ3x_32_L},
 {	0,HQ3x_16_R,HQ3x_16_R,HQ3x_32_R}
@@ -399,7 +459,11 @@ ScalerComplexBlock_t ScaleHQ3x ={
 
 ScalerComplexBlock_t ScaleSuper2xSaI ={
 	"Super2xSaI",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,
 {	0,Super2xSaI_16_L,Super2xSaI_16_L,Super2xSaI_32_L},
 {	0,Super2xSaI_16_R,Super2xSaI_16_R,Super2xSaI_32_R}
@@ -407,7 +471,11 @@ ScalerComplexBlock_t ScaleSuper2xSaI ={
 
 ScalerComplexBlock_t Scale2xSaI ={
 	"2xSaI",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,
 {	0,_2xSaI_16_L,_2xSaI_16_L,_2xSaI_32_L},
 {	0,_2xSaI_16_R,_2xSaI_16_R,_2xSaI_32_R}
@@ -415,7 +483,11 @@ ScalerComplexBlock_t Scale2xSaI ={
 
 ScalerComplexBlock_t ScaleSuperEagle ={
 	"SuperEagle",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,
 {	0,SuperEagle_16_L,SuperEagle_16_L,SuperEagle_32_L},
 {	0,SuperEagle_16_R,SuperEagle_16_R,SuperEagle_32_R}
@@ -423,7 +495,11 @@ ScalerComplexBlock_t ScaleSuperEagle ={
 
 ScalerComplexBlock_t ScaleAdvInterp2x = {
 	"AdvInterp2x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	2,2,
 {	0,AdvInterp2x_15_L,AdvInterp2x_16_L,AdvInterp2x_32_L},
 {	0,AdvInterp2x_15_R,AdvInterp2x_16_R,AdvInterp2x_32_R}
@@ -431,7 +507,11 @@ ScalerComplexBlock_t ScaleAdvInterp2x = {
 
 ScalerComplexBlock_t ScaleAdvInterp3x = {
 	"AdvInterp3x",
+#ifdef HW_RVL	
 	GFX_CAN_16,
+#else
+	GFX_CAN_15|GFX_CAN_16|GFX_CAN_32|GFX_RGBONLY,
+#endif
 	3,3,
 {	0,AdvInterp3x_15_L,AdvInterp3x_16_L,AdvInterp3x_32_L},
 {	0,AdvInterp3x_15_R,AdvInterp3x_16_R,AdvInterp3x_32_R}

src/gui/sdl_gui.cpp

@@ -111,7 +111,12 @@ static GUI::ScreenSDL *UI_Startup(GUI::ScreenSDL *screen) {
 
 	old_unicode = SDL_EnableUNICODE(1);
 	SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY,SDL_DEFAULT_REPEAT_INTERVAL);
+#ifdef HW_RVL
+	// This won't work because the Masks are wrong for 16-bit.
 	screenshot = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 16, GUI::Color::RedMask, GUI::Color::GreenMask, GUI::Color::BlueMask, 0);
+#else
+	screenshot = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32, GUI::Color::RedMask, GUI::Color::GreenMask, GUI::Color::BlueMask, 0);
+#endif	
 
 	// create screenshot for fade effect
 	int rs = screenshot->format->Rshift, gs = screenshot->format->Gshift, bs = screenshot->format->Bshift, am = GUI::Color::AlphaMask;
@@ -124,7 +129,12 @@ static GUI::ScreenSDL *UI_Startup(GUI::ScreenSDL *screen) {
 		}
 	}
 
+#ifdef HW_RVL
+	// This won't work because the Masks are wrong for 16-bit.
 	background = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 16, GUI::Color::RedMask, GUI::Color::GreenMask, GUI::Color::BlueMask, GUI::Color::AlphaMask);
+#else
+	background = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32, GUI::Color::RedMask, GUI::Color::GreenMask, GUI::Color::BlueMask, GUI::Color::AlphaMask);
+#endif	
 	// use a blurred and sepia-toned screenshot as menu background
 	for (int y = 0; y < h; y++) {
 		Bit32u *bg = (Bit32u*)(y*background->pitch + (char*)background->pixels);
@@ -151,7 +161,11 @@ static GUI::ScreenSDL *UI_Startup(GUI::ScreenSDL *screen) {
 	mousetoggle = mouselocked;
 	if (mouselocked) GFX_CaptureMouse();
 
+#ifdef HW_RVL
 	SDL_Surface* sdlscreen = SDL_SetVideoMode(w, h, 16, SDL_SWSURFACE|(fs?SDL_FULLSCREEN:0));
+#else
+	SDL_Surface* sdlscreen = SDL_SetVideoMode(w, h, 32, SDL_SWSURFACE|(fs?SDL_FULLSCREEN:0));
+#endif	
 	if (sdlscreen == NULL) E_Exit("Could not initialize video mode %ix%ix32 for UI: %s", w, h, SDL_GetError());
 
 	// fade out

src/gui/sdl_mapper.cpp

@@ -2283,7 +2283,11 @@ void MAPPER_Run(bool pressed) {
 
 	/* Be sure that there is no update in progress */
 	GFX_EndUpdate( 0 );
+#ifdef HW_RVL	
 	mapper.surface=SDL_SetVideoMode(640,480,16,0);
+#else
+	mapper.surface=SDL_SetVideoMode(640,480,8,0);
+#endif
 	if (mapper.surface == NULL) E_Exit("Could not initialize video mode for mapper: %s",SDL_GetError());
 
 	/* Set some palette entries */

src/gui/sdlmain.cpp

@@ -980,9 +980,9 @@ static void GUI_StartUp(Section * sec) {
 	/* Set Icon (must be done before any sdl_setvideomode call) */
 	/* But don't set it on OS X, as we use a nicer external icon there. */
 #if WORDS_BIGENDIAN
-	SDL_Surface* logos= SDL_CreateRGBSurfaceFrom((void*)logo,32,32,16,128,0xff000000,0x00ff0000,0x0000ff00,0);
+	SDL_Surface* logos= SDL_CreateRGBSurfaceFrom((void*)logo,32,32,32,128,0xff000000,0x00ff0000,0x0000ff00,0);
 #else
-	SDL_Surface* logos= SDL_CreateRGBSurfaceFrom((void*)logo,32,32,16,128,0x000000ff,0x0000ff00,0x00ff0000,0);
+	SDL_Surface* logos= SDL_CreateRGBSurfaceFrom((void*)logo,32,32,32,128,0x000000ff,0x0000ff00,0x00ff0000,0);
 #endif
 	SDL_WM_SetIcon(logos,NULL);
 #endif
@@ -1666,6 +1666,15 @@ int main(int argc, char* argv[]) {
 	SDL_WM_GrabInput(SDL_GRAB_OFF);
 	SDL_ShowCursor(SDL_ENABLE);
 
+#ifdef HW_RVL
+	printf("Press A to return to homebrew channel.\n");
+	while (1) {
+		WPAD_ScanPads();
+		u16 buttonsDown = WPAD_ButtonsDown(0);
+		if( buttonsDown & WPAD_BUTTON_A ) break;
+		if( buttonsDown & WPAD_BUTTON_HOME ) exit(0);
+  	}
+#endif
 	SDL_Quit();//Let's hope sdl will quit as well when it catches an exception
 	return 0;
 };

src/libs/gui_tk/gui_tk.cpp

@@ -1566,12 +1566,21 @@ int main(int argc, char *argv[])
 
 	atexit(SDL_Quit);
 
+#ifdef HW_RVL
 	screen = SDL_SetVideoMode(640, 480, 16, SDL_SWSURFACE);
+	if (screen == NULL) {
+		fprintf(stderr, "Couldn't set 640x480x16 video mode: %s\n", SDL_GetError());
+		exit(1);
+	}
+	printf("GUI:: color depth %i\n",screen->format->BitsPerPixel);
+#else
+	screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
 	if (screen == NULL) {
 		fprintf(stderr, "Couldn't set 640x480x32 video mode: %s\n", SDL_GetError());
 		exit(1);
 	}
 	printf("GUI:: color depth %i\n",screen->format->BitsPerPixel);
+#endif
 
 	SDL_EnableUNICODE(true);
 	SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY,SDL_DEFAULT_REPEAT_INTERVAL);

src/shell/shell.cpp

@@ -635,7 +635,7 @@ void SHELL_Init() {
 	SHELL_ProgramStart(&first_shell);
 
 #ifdef HW_RVL
-	printf("Press A to continue to a crash, or Home to exit.\n");
+	printf("Press A to continue (or Home to exit).\n");
 	while (1) {
 		WPAD_ScanPads();
 		u16 buttonsDown = WPAD_ButtonsDown(0);