From b9a37077c340d57267d6b73f233a8c8674fb3e22 Mon Sep 17 00:00:00 2001
From: neauoire <aliceffekt@gmail.com>
Date: Wed, 5 Jan 2022 19:48:51 -0800
Subject: [PATCH] Started work on the hypervisor

---
 src/devices/system.c |  8 ++++----
 src/uxn.c            | 10 ++++++----
 src/uxn.h            |  4 ++--
 src/uxncli.c         |  9 +++++----
 src/uxnemu.c         | 11 ++++++++---
 5 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/src/devices/system.c b/src/devices/system.c
index 6e38e73..5ccb7d6 100644
--- a/src/devices/system.c
+++ b/src/devices/system.c
@@ -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);
 	}
 }
diff --git a/src/uxn.c b/src/uxn.c
index 90d912b..7778aef 100644
--- a/src/uxn.c
+++ b/src/uxn.c
@@ -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;
 }
diff --git a/src/uxn.h b/src/uxn.h
index e3633c8..7103446 100644
--- a/src/uxn.h
+++ b/src/uxn.h
@@ -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));
diff --git a/src/uxncli.c b/src/uxncli.c
index f7e14e2..d2d4605 100644
--- a/src/uxncli.c
+++ b/src/uxncli.c
@@ -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);
diff --git a/src/uxnemu.c b/src/uxnemu.c
index 3fdf125..7451bb7 100644
--- a/src/uxnemu.c
+++ b/src/uxnemu.c
@@ -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.");