@@ -45,8 +45,8 @@ Uint8

 system_dei(Device *d, Uint8 port)

 {

 	switch(port) {

-	case 0x2: return d->u->wst.ptr;

-	case 0x3: return d->u->rst.ptr;

+	case 0x2: return d->u->wst->ptr;

+	case 0x3: return d->u->rst->ptr;

 	default: return d->dat[port];

 	}

 }

@@ -56,8 +56,8 @@ system_deo(Device *d, Uint8 port)

 {

 	switch(port) {

 	case 0x1: DEVPEEK16(d->vector, 0x0); break;

-	case 0x2: d->u->wst.ptr = d->dat[port]; break;

-	case 0x3: d->u->rst.ptr = d->dat[port]; break;

+	case 0x2: d->u->wst->ptr = d->dat[port]; break;

+	case 0x3: d->u->rst->ptr = d->dat[port]; break;

 	default: system_deo_special(d, port);

 	}

 }

@@ -39,13 +39,13 @@ uxn_eval(Uxn *u, Uint16 pc)

 	Stack *src, *dst;

 	Device *dev;

 	if(!pc || u->dev[0].dat[0xf]) return 0;

-	if(u->wst.ptr > 0xf8) u->wst.ptr = 0xf8;

+	if(u->wst->ptr > 0xf8) u->wst->ptr = 0xf8;

 	while((instr = u->ram[pc++])) {

 		/* Return Mode */

 		if(instr & 0x40) {

-			src = &u->rst; dst = &u->wst;

+			src = u->rst; dst = u->wst;

 		} else {

-			src = &u->wst; dst = &u->rst;

+			src = u->wst; dst = u->rst;

 		}

 		/* Keep Mode */

 		if(instr & 0x80) {

@@ -108,12 +108,14 @@ err:

 /* clang-format on */

 int

-uxn_boot(Uxn *u, Uint8 *memory)

+uxn_boot(Uxn *u, Stack *wst, Stack *rst, Uint8 *memory)

 {

 	Uint32 i;

 	char *cptr = (char *)u;

 	for(i = 0; i < sizeof(*u); i++)

 		cptr[i] = 0x00;

+	u->wst = wst;

+	u->rst = rst;

 	u->ram = memory;

 	return 1;

 }

@@ -38,12 +38,12 @@ typedef struct Device {

 } Device;

 typedef struct Uxn {

-	Stack wst, rst;

+	Stack *wst, *rst;

 	Uint8 *ram;

 	Device dev[16];

 } Uxn;

-int uxn_boot(Uxn *c, Uint8 *memory);

+int uxn_boot(Uxn *u, Stack *wst, Stack *rst, Uint8 *memory);

 int uxn_eval(Uxn *u, Uint16 pc);

 int uxn_halt(Uxn *u, Uint8 error, Uint16 addr);

 Device *uxn_port(Uxn *u, Uint8 id, Uint8 (*deifn)(Device *, Uint8), void (*deofn)(Device *, Uint8));

@@ -50,8 +50,8 @@ void

 system_deo_special(Device *d, Uint8 port)

 {

 	if(port == 0xe) {

-		inspect(&d->u->wst, "Working-stack");

-		inspect(&d->u->rst, "Return-stack");

+		inspect(d->u->wst, "Working-stack");

+		inspect(d->u->rst, "Return-stack");

 	}

 }

@@ -133,7 +133,7 @@ load(Uxn *u, char *filepath)

 	return 1;

 }

-static Uint8 *memory;

+static Uint8 *shadow, *memory;

 int

 main(int argc, char **argv)

@@ -141,8 +141,9 @@ main(int argc, char **argv)

 	Uxn u;

 	int i, loaded = 0;

+	shadow = (Uint8 *)calloc(0xffff, sizeof(Uint8));

 	memory = (Uint8 *)calloc(0xffff, sizeof(Uint8));

-	if(!uxn_boot(&u, memory))

+	if(!uxn_boot(&u, (Stack *)(shadow + 0x200), (Stack *)(shadow + 0x400), memory))

 		return error("Boot", "Failed");

 	/* system   */ devsystem = uxn_port(&u, 0x0, system_dei, system_deo);

@@ -44,6 +44,7 @@ static SDL_Rect gRect;

 static Device *devsystem, *devscreen, *devmouse, *devctrl, *devaudio0, *devconsole;

 static Uint8 zoom = 1;

 static Uint32 stdin_event, audio0_event;

+static Uxn hypervisor;

 static int

 clamp(int val, int min, int max)

@@ -126,7 +127,7 @@ static void

 redraw(Uxn *u)

 {

 	if(devsystem->dat[0xe])

-		screen_debug(&uxn_screen, u->wst.dat, u->wst.ptr, u->rst.ptr, u->ram);

+		screen_debug(&uxn_screen, u->wst->dat, u->wst->ptr, u->rst->ptr, u->ram);

 	screen_redraw(&uxn_screen, uxn_screen.pixels);

 	if(SDL_UpdateTexture(gTexture, NULL, uxn_screen.pixels, uxn_screen.width * sizeof(Uint32)) != 0)

 		error("SDL_UpdateTexture", SDL_GetError());

@@ -272,13 +273,17 @@ load(Uxn *u, char *rom)

 	return 1;

 }

-static Uint8 *memory;

+static Uint8 *shadow, *memory;

 static int

 start(Uxn *u, char *rom)

 {

 	memory = (Uint8 *)calloc(0xffff, sizeof(Uint8));

-	if(!uxn_boot(u, memory))

+	shadow = (Uint8 *)calloc(0xffff, sizeof(Uint8));

+

+	if(!uxn_boot(&hypervisor, (Stack *)(shadow + 0x600), (Stack *)(shadow + 0x800), shadow))

+		return error("Boot", "Failed to start uxn.");

+	if(!uxn_boot(u, (Stack *)(shadow + 0x200), (Stack *)(shadow + 0x400), memory))

 		return error("Boot", "Failed to start uxn.");

 	if(!load(u, rom))

 		return error("Boot", "Failed to load rom.");