From 543ffac706d5a832c8e02ba1f9362df76a1a1bf0 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Wed, 14 Jan 2015 22:34:10 -0800
Subject: [PATCH] GBA: Add prefetch data to savestate

---
 src/gba/gba-serialize.c | 27 +++++++++++++++++++++++----
 src/gba/gba-serialize.h | 11 +++++++++--
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/src/gba/gba-serialize.c b/src/gba/gba-serialize.c
index 19f418fa2..21380e3ea 100644
--- a/src/gba/gba-serialize.c
+++ b/src/gba/gba-serialize.c
@@ -40,6 +40,10 @@ void GBASerialize(struct GBA* gba, struct GBASerializedState* state) {
 	memcpy(state->cpu.bankedRegisters, gba->cpu->bankedRegisters, 6 * 7 * sizeof(int32_t));
 	memcpy(state->cpu.bankedSPSRs, gba->cpu->bankedSPSRs, 6 * sizeof(int32_t));
 
+	state->biosPrefetch = gba->memory.biosPrefetch;
+	state->cpuPrefetch[0] = gba->cpu->prefetch[0];
+	state->cpuPrefetch[1] = gba->cpu->prefetch[1];
+
 	GBAMemorySerialize(&gba->memory, state);
 	GBAIOSerialize(gba, state);
 	GBAVideoSerialize(&gba->video, state);
@@ -80,14 +84,29 @@ void GBADeserialize(struct GBA* gba, struct GBASerializedState* state) {
 	memcpy(gba->cpu->bankedSPSRs, state->cpu.bankedSPSRs, 6 * sizeof(int32_t));
 	gba->cpu->privilegeMode = gba->cpu->cpsr.priv;
 	gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
+	if (state->biosPrefetch) {
+		gba->memory.biosPrefetch = state->biosPrefetch;
+	}
 	if (gba->cpu->cpsr.t) {
 		gba->cpu->executionMode = MODE_THUMB;
-		LOAD_16(gba->cpu->prefetch[0], (gba->cpu->gprs[ARM_PC] - WORD_SIZE_THUMB) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
-		LOAD_16(gba->cpu->prefetch[1], (gba->cpu->gprs[ARM_PC]) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
+		if (state->cpuPrefetch[0] && state->cpuPrefetch[1]) {
+			gba->cpu->prefetch[0] = state->cpuPrefetch[0] & 0xFFFF;
+			gba->cpu->prefetch[1] = state->cpuPrefetch[1] & 0xFFFF;
+		} else {
+			// Maintain backwards compat
+			LOAD_16(gba->cpu->prefetch[0], (gba->cpu->gprs[ARM_PC] - WORD_SIZE_THUMB) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
+			LOAD_16(gba->cpu->prefetch[1], (gba->cpu->gprs[ARM_PC]) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
+		}
 	} else {
 		gba->cpu->executionMode = MODE_ARM;
-		LOAD_32(gba->cpu->prefetch[0], (gba->cpu->gprs[ARM_PC] - WORD_SIZE_ARM) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
-		LOAD_32(gba->cpu->prefetch[1], (gba->cpu->gprs[ARM_PC]) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
+		if (state->cpuPrefetch[0] && state->cpuPrefetch[1]) {
+			gba->cpu->prefetch[0] = state->cpuPrefetch[0];
+			gba->cpu->prefetch[1] = state->cpuPrefetch[1];
+		} else {
+			// Maintain backwards compat
+			LOAD_32(gba->cpu->prefetch[0], (gba->cpu->gprs[ARM_PC] - WORD_SIZE_ARM) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
+			LOAD_32(gba->cpu->prefetch[1], (gba->cpu->gprs[ARM_PC]) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
+		}
 	}
 
 	GBAMemoryDeserialize(&gba->memory, state);
diff --git a/src/gba/gba-serialize.h b/src/gba/gba-serialize.h
index ddf905458..7bba97bf7 100644
--- a/src/gba/gba-serialize.h
+++ b/src/gba/gba-serialize.h
@@ -150,7 +150,11 @@ extern const uint32_t GBA_SAVESTATE_MAGIC;
  * | 0x002C1 - 0x002C3: Flags
  *   | bits 0 - 1: Tilt state machine
  *   | bits 2 - 31: Reserved
- * 0x002C4 - 0x002FF: Reserved (leave zero)
+ * 0x002C4 - 0x002F3: Reserved (leave zero)
+ * 0x002F4 - 0x002FF: Prefetch
+ * | 0x002F4 - 0x002F7: GBA BIOS bus prefetch
+ * | 0x002F8 - 0x002FB: CPU prefecth (decode slot)
+ * | 0x002FC - 0x002FF: CPU prefetch (fetch slot)
  * 0x00300 - 0x00303: Associated movie stream ID for record/replay (or 0 if no stream)
  * 0x00304 - 0x003FF: Reserved (leave zero)
  * 0x00400 - 0x007FF: I/O memory
@@ -267,7 +271,10 @@ struct GBASerializedState {
 		unsigned : 22;
 	} gpio;
 
-	uint32_t reservedGpio[15];
+	uint32_t reservedGpio[12];
+
+	uint32_t biosPrefetch;
+	uint32_t cpuPrefetch[2];
 
 	uint32_t associatedStreamId;