From c34a8b3249720ad254bbc4c9b70fe74380b77859 Mon Sep 17 00:00:00 2001
From: dinkc64 <12570148+dinkc64@users.noreply.github.com>
Date: Sun, 16 Nov 2014 19:55:45 +0000
Subject: [PATCH] Musashi savestate fix

---
 src/cpu/m68000_intf.cpp | 24 ++----------------------
 src/cpu/m68k/m68k.h     |  3 +++
 src/cpu/m68k/m68kcpu.c  |  6 ++++++
 src/cpu/m68k/m68kcpu.h  |  3 +++
 4 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/src/cpu/m68000_intf.cpp b/src/cpu/m68000_intf.cpp
index 9b7634453..8af1f3433 100644
--- a/src/cpu/m68000_intf.cpp
+++ b/src/cpu/m68000_intf.cpp
@@ -1987,26 +1987,6 @@ bool SekDbgSetRegister(SekRegister nRegister, UINT32 nValue)
 // ----------------------------------------------------------------------------
 // Savestate support
 
-// The following block of pointers is actually the end part of the SekM68KContext data
-// We preserve these for savestate portability because the addresses/values can be
-// specific to a certain system.
-struct m68ki_cpu_core_pointerblock
-{
-	const UINT8* cyc_instruction;
-	const UINT8* cyc_exception;
-
-	int  (*int_ack_callback)(int int_line);           /* Interrupt Acknowledge */
-	void (*bkpt_ack_callback)(unsigned int data);     /* Breakpoint Acknowledge */
-	void (*reset_instr_callback)(void);               /* Called when a RESET instruction is encountered */
-	void (*cmpild_instr_callback)(unsigned int, int); /* Called when a CMPI.L #v, Dn instruction is encountered */
-	void (*rte_instr_callback)(void);                 /* Called when a RTE instruction is encountered */
-	int  (*tas_instr_callback)(void);                 /* Called when a TAS instruction is encountered */
-	void (*pc_changed_callback)(unsigned int new_pc); /* Called when the PC changes by a large amount */
-	void (*set_fc_callback)(unsigned int new_fc);     /* Called when the CPU function code changes */
-	void (*instr_hook_callback)(unsigned int pc);     /* Called every instruction cycle prior to execution */
-};
-
-
 INT32 SekScan(INT32 nAction)
 {
 #if defined FBA_DEBUG
@@ -2015,7 +1995,6 @@ INT32 SekScan(INT32 nAction)
 
 	// Scan the 68000 states
 	struct BurnArea ba;
-	struct m68ki_cpu_core_pointerblock m68kpointerblock;
 
 	if ((nAction & ACB_DRIVER_DATA) == 0) {
 		return 1;
@@ -2081,7 +2060,8 @@ INT32 SekScan(INT32 nAction)
 			if (nSekCPUType[i] != 0) {
 				ba.Data = SekM68KContext[i];
 				// for savestate portability: preserve our cpu's pointers, they are set up in DrvInit() and can be specific to different systems.
-				ba.nLen = nSekM68KContextSize[i] - sizeof(m68kpointerblock);
+				// Therefore we scan the cpu context structure up until right before the pointers
+				ba.nLen = m68k_context_size_no_pointers();
 				ba.szName = szName;
 				BurnAcb(&ba);
 			}
diff --git a/src/cpu/m68k/m68k.h b/src/cpu/m68k/m68k.h
index 3ffe19cf5..bd89f6209 100644
--- a/src/cpu/m68k/m68k.h
+++ b/src/cpu/m68k/m68k.h
@@ -336,6 +336,9 @@ void m68k_pulse_halt(void);
 /* Get the size of the cpu context in bytes */
 unsigned int m68k_context_size(void);
 
+/* Get the size of the cpu context without the pointer-block, for savestates */
+unsigned int m68k_context_size_no_pointers(void);
+
 /* Get a cpu context */
 unsigned int m68k_get_context(void* dst);
 
diff --git a/src/cpu/m68k/m68kcpu.c b/src/cpu/m68k/m68kcpu.c
index b9a927175..d2faf7022 100644
--- a/src/cpu/m68k/m68kcpu.c
+++ b/src/cpu/m68k/m68kcpu.c
@@ -965,6 +965,12 @@ unsigned int m68k_context_size()
 	return sizeof(m68ki_cpu_core);
 }
 
+/* Used to calculate the context size minus the system-specific pointers, for savestates */
+unsigned int m68k_context_size_no_pointers()
+{
+	return (int)&m68ki_cpu.pointer_block_divider - (int)&m68ki_cpu;
+}
+
 unsigned int m68k_get_context(void* dst)
 {
 	if(dst) *(m68ki_cpu_core*)dst = m68ki_cpu;
diff --git a/src/cpu/m68k/m68kcpu.h b/src/cpu/m68k/m68kcpu.h
index aed8fdaaf..97c174502 100644
--- a/src/cpu/m68k/m68kcpu.h
+++ b/src/cpu/m68k/m68kcpu.h
@@ -898,6 +898,9 @@ struct _m68ki_cpu_core
 	uint virq_state;
 	uint nmi_pending;
 
+	/* Designates the end of the CPU context variables and beginning of system-specific pointers */
+	uint8 pointer_block_divider;                      /* Used to calculate the context-size for savestates */
+
 	const uint8* cyc_instruction;
 	const uint8* cyc_exception;