From dc263295dd58f6b03726767220f9b401a53a971c Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Sun, 17 Nov 2024 03:34:33 -0800
Subject: [PATCH] GBA Memory: Add unlicensed cart write handling stub

---
 include/mgba/internal/gba/cart/unlicensed.h |  1 +
 src/gba/cart/unlicensed.c                   | 13 +++++++++++++
 src/gba/memory.c                            |  4 ++++
 3 files changed, 18 insertions(+)

diff --git a/include/mgba/internal/gba/cart/unlicensed.h b/include/mgba/internal/gba/cart/unlicensed.h
index ec13abb55..816aa1dfd 100644
--- a/include/mgba/internal/gba/cart/unlicensed.h
+++ b/include/mgba/internal/gba/cart/unlicensed.h
@@ -60,6 +60,7 @@ void GBAUnlCartReset(struct GBA*);
 void GBAUnlCartUnload(struct GBA*);
 void GBAUnlCartDetect(struct GBA*);
 void GBAUnlCartWriteSRAM(struct GBA*, uint32_t address, uint8_t value);
+void GBAUnlCartWriteROM(struct GBA*, uint32_t address, uint16_t value);
 
 struct GBASerializedState;
 void GBAUnlCartSerialize(const struct GBA* gba, struct GBASerializedState* state);
diff --git a/src/gba/cart/unlicensed.c b/src/gba/cart/unlicensed.c
index 318ffe891..442ec9865 100644
--- a/src/gba/cart/unlicensed.c
+++ b/src/gba/cart/unlicensed.c
@@ -126,6 +126,19 @@ void GBAUnlCartWriteSRAM(struct GBA* gba, uint32_t address, uint8_t value) {
 	gba->memory.savedata.data[address & (GBA_SIZE_SRAM - 1)] = value;
 }
 
+void GBAUnlCartWriteROM(struct GBA* gba, uint32_t address, uint16_t value) {
+	struct GBAUnlCart* unl = &gba->memory.unl;
+
+	switch (unl->type) {
+	case GBA_UNL_CART_VFAME:
+	case GBA_UNL_CART_NONE:
+		break;
+	case GBA_UNL_CART_MULTICART:
+		mLOG(GBA_MEM, STUB, "Unimplemented writing to ROM %07X:%04X", address, value);
+		break;
+	}
+}
+
 static void _multicartSettle(struct mTiming* timing, void* context, uint32_t cyclesLate) {
 	UNUSED(timing);
 	UNUSED(cyclesLate);
diff --git a/src/gba/memory.c b/src/gba/memory.c
index 53d0f7cc9..1561aef91 100644
--- a/src/gba/memory.c
+++ b/src/gba/memory.c
@@ -963,6 +963,10 @@ void GBAStore16(struct ARMCore* cpu, uint32_t address, int16_t value, int* cycle
 				break;
 			}
 		}
+		if (memory->unl.type) {
+			GBAUnlCartWriteROM(gba, address & (GBA_SIZE_ROM0 - 1), value);
+			break;
+		}
 		mLOG(GBA_MEM, GAME_ERROR, "Bad cartridge Store16: 0x%08X", address);
 		break;
 	case GBA_REGION_ROM2_EX: