From 73e965c105a60b7e05321d641edd4a3967695fe6 Mon Sep 17 00:00:00 2001
From: d_m <d_m@plastic-idolatry.com>
Date: Mon, 18 Dec 2023 22:54:47 -0500
Subject: [PATCH] add support for uuid-based extensions

---
 src/devices/system.c | 52 +++++++++++++++++++++++++++++++++++++-------
 1 file changed, 44 insertions(+), 8 deletions(-)

diff --git a/src/devices/system.c b/src/devices/system.c
index 819dac5..53655d9 100644
--- a/src/devices/system.c
+++ b/src/devices/system.c
@@ -101,6 +101,46 @@ system_init(Uxn *u, Uint8 *ram, char *rom)
 	return 1;
 }
 
+static void
+system_expansion_copy(Uxn *u, Uint8 *ram, Uint16 addr)
+{
+	Uint16 i, length = PEEK2(ram + addr + 1);
+	Uint16 a_page = PEEK2(ram + addr + 1 + 2), a_addr = PEEK2(ram + addr + 1 + 4);
+	Uint16 b_page = PEEK2(ram + addr + 1 + 6), b_addr = PEEK2(ram + addr + 1 + 8);
+	int src = (a_page % RAM_PAGES) * 0x10000, dst = (b_page % RAM_PAGES) * 0x10000;
+	for(i = 0; i < length; i++)
+		ram[dst + (Uint16)(b_addr + i)] = ram[src + (Uint16)(a_addr + i)];
+}
+
+static int
+uuid_eq(Uint8 *m, Uint8 uuid[16])
+{
+	for(int i = 0; i < 16; i++)
+		if (m[i] != uuid[i])
+			return 0;
+	return 1;
+}
+
+/* console device: 01231250-d878-4462-bc41-d0927645a2fa */
+static Uint8 console_uuid[16] = {
+  0x01, 0x23, 0x12, 0x50, 0xd8, 0x78, 0x44, 0x62,
+  0xbc, 0x41, 0xd0, 0x92, 0x76, 0x45, 0xa2, 0xfa
+};
+
+static void
+system_expansion_uxn38_device(Uxn *u, Uint8 *ram, Uint16 addr)
+{
+	Uint8 dev_id = ram[addr + 1];
+	Uint8 *uuid = &ram[addr + 2];
+	if(dev_id == 0x10 && uuid_eq(uuid, console_uuid) != 0) {
+		ram[addr + 18] = 0x00;
+		ram[addr + 19] = 0xff;
+	} else {
+		ram[addr + 18] = 0x00;
+		ram[addr + 19] = 0x00;
+	}
+}
+
 /* IO */
 
 Uint8
@@ -122,14 +162,10 @@ system_deo(Uxn *u, Uint8 *d, Uint8 port)
 	case 0x3:
 		ram = u->ram;
 		addr = PEEK2(d + 2);
-		if(ram[addr] == 0x1) {
-			Uint16 i, length = PEEK2(ram + addr + 1);
-			Uint16 a_page = PEEK2(ram + addr + 1 + 2), a_addr = PEEK2(ram + addr + 1 + 4);
-			Uint16 b_page = PEEK2(ram + addr + 1 + 6), b_addr = PEEK2(ram + addr + 1 + 8);
-			int src = (a_page % RAM_PAGES) * 0x10000, dst = (b_page % RAM_PAGES) * 0x10000;
-			for(i = 0; i < length; i++)
-				ram[dst + (Uint16)(b_addr + i)] = ram[src + (Uint16)(a_addr + i)];
-		}
+		if(ram[addr] == 0x1)
+			system_expansion_copy(u, ram, addr);
+		else if(ram[addr] == 0x3)
+			system_expansion_uxn38_device(u, ram, addr);
 		break;
 	case 0x4:
 		u->wst.ptr = d[4];