From 3d77a9d922dbdcf6e92b5f63e577f61fc43776aa Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Fri, 2 Jun 2017 11:26:53 -0700
Subject: [PATCH] GB MBC: Fix initialization and swapping

---
 src/gb/gb.c        | 19 ++++++++++++-------
 src/gb/mbc.c       |  8 ++++++++
 src/gb/memory.c    |  6 ------
 src/gb/overrides.c |  2 ++
 4 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/src/gb/gb.c b/src/gb/gb.c
index 4c83984f5..a97fe97ef 100644
--- a/src/gb/gb.c
+++ b/src/gb/gb.c
@@ -124,7 +124,7 @@ bool GBLoadROM(struct GB* gb, struct VFile* vf) {
 	gb->memory.romBase = gb->memory.rom;
 	gb->memory.romSize = gb->pristineRomSize;
 	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
-	GBMBCSwitchBank(gb, gb->memory.currentBank);
+	GBMBCInit(gb);
 
 	if (gb->cpu) {
 		struct LR35902Core* cpu = gb->cpu;
@@ -135,12 +135,6 @@ bool GBLoadROM(struct GB* gb, struct VFile* vf) {
 	return true;
 }
 
-bool GBLoadSave(struct GB* gb, struct VFile* vf) {
-	gb->sramVf = vf;
-	gb->sramRealVf = vf;
-	return vf;
-}
-
 static void GBSramDeinit(struct GB* gb) {
 	if (gb->sramVf) {
 		gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
@@ -154,6 +148,16 @@ static void GBSramDeinit(struct GB* gb) {
 	gb->memory.sram = 0;
 }
 
+bool GBLoadSave(struct GB* gb, struct VFile* vf) {
+	GBSramDeinit(gb);
+	gb->sramVf = vf;
+	gb->sramRealVf = vf;
+	if (gb->sramSize) {
+		GBResizeSram(gb, gb->sramSize);
+	}
+	return vf;
+}
+
 void GBResizeSram(struct GB* gb, size_t size) {
 	if (gb->memory.sram && size <= gb->sramSize) {
 		return;
@@ -280,6 +284,7 @@ void GBUnloadROM(struct GB* gb) {
 		gb->romVf = NULL;
 	}
 	gb->memory.rom = NULL;
+	gb->memory.mbcType = GB_MBC_AUTODETECT;
 	gb->isPristine = false;
 
 	GBSavedataUnmask(gb);
diff --git a/src/gb/mbc.c b/src/gb/mbc.c
index ae69defc6..0710f10c0 100644
--- a/src/gb/mbc.c
+++ b/src/gb/mbc.c
@@ -204,6 +204,14 @@ void GBMBCInit(struct GB* gb) {
 		break;
 	}
 
+	gb->memory.currentBank = 1;
+	gb->memory.sramCurrentBank = 0;
+	gb->memory.sramAccess = false;
+	gb->memory.rtcAccess = false;
+	gb->memory.activeRtcReg = 0;
+	gb->memory.rtcLatched = false;
+	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
+
 	GBResizeSram(gb, gb->sramSize);
 
 	if (gb->memory.mbcType == GB_MBC3_RTC) {
diff --git a/src/gb/memory.c b/src/gb/memory.c
index 3fde79010..8484941b7 100644
--- a/src/gb/memory.c
+++ b/src/gb/memory.c
@@ -158,12 +158,6 @@ void GBMemoryReset(struct GB* gb) {
 	gb->memory.hdmaEvent.callback = _GBMemoryHDMAService;
 	gb->memory.hdmaEvent.priority = 0x41;
 
-	gb->memory.sramAccess = false;
-	gb->memory.rtcAccess = false;
-	gb->memory.activeRtcReg = 0;
-	gb->memory.rtcLatched = false;
-	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
-
 	memset(&gb->memory.hram, 0, sizeof(gb->memory.hram));
 	switch (gb->memory.mbcType) {
 	case GB_MBC1:
diff --git a/src/gb/overrides.c b/src/gb/overrides.c
index d86f08f5f..70d11cd22 100644
--- a/src/gb/overrides.c
+++ b/src/gb/overrides.c
@@ -6,6 +6,7 @@
 #include <mgba/internal/gb/overrides.h>
 
 #include <mgba/internal/gb/gb.h>
+#include <mgba/internal/gb/mbc.h>
 
 #include <mgba-util/configuration.h>
 #include <mgba-util/crc32.h>
@@ -102,6 +103,7 @@ void GBOverrideApply(struct GB* gb, const struct GBCartridgeOverride* override)
 
 	if (override->mbc != GB_MBC_AUTODETECT) {
 		gb->memory.mbcType = override->mbc;
+		GBMBCInit(gb);
 	}
 }