From: Toni Wilen <twilen@winuae.net>
Date: Sun, 5 Jan 2020 19:51:25 +0000 (+0200)
Subject: Fixed return modified register value in 68030 mmu bus error exception handler if... 
X-Git-Tag: 4400~189
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=944f43a028867f61617771b06d8c38c2559893f9;p=francis%2Fwinuae.git

Fixed return modified register value in 68030 mmu bus error exception handler if mode was -(an) or (an)+.
---

diff --git a/cpummu30.cpp b/cpummu30.cpp
index 6616a16f..4d744c54 100644
--- a/cpummu30.cpp
+++ b/cpummu30.cpp
@@ -1762,17 +1762,35 @@ static void dump_opcode(uae_u16 opcode)
 
 // if CPU is 68030 and faulted access' addressing mode was -(an) or (an)+
 // register content is not restored when exception starts.
-static void mmu030fixupreg(int i)
+static uae_u8 mmu030fixupreg(int i)
 {
 	struct mmufixup *m = &mmufixup[i];
+	uae_u8 v = 0;
 	if (m->reg < 0)
+		return v;
+	if (!(m->reg & 0x300))
+		return v;
+	v = m->reg & 7;
+	v |= ((m->reg >> 10) & 3) << 3; // size
+	if (m->reg & 0x200) // -(an)?
+		v |= 1 << 5;
+	v |= 1 << 6;
+	return v;
+}
+
+static void mmu030fixupmod(uae_u8 data, int dir, int idx)
+{
+	if (!data)
 		return;
-	int size = 1 << ((m->reg >> 10) & 3);
-	if (m->reg & 0x100) {
-		m68k_areg(regs, m->reg & 15) += size;
-	}
-	if (m->reg & 0x200) {
-		m68k_areg(regs, m->reg & 15) -= size;
+	int reg = data & 7;
+	int adj = (data & (1 << 5)) ? -1 : 1;
+	if (dir)
+		adj = -adj;
+	adj <<= (data >> 3) & 3;
+	m68k_areg(regs, reg) += adj;
+	if (idx >= 0) {
+		struct mmufixup *m = &mmufixup[idx];
+		m->value += adj;
 	}
 }
 
@@ -1783,9 +1801,17 @@ void mmu030_page_fault(uaecptr addr, bool read, int flags, uae_u32 fc)
 		fc = regs.mmu_ssw & MMU030_SSW_FC_MASK;
 		flags = regs.mmu_ssw & ~(MMU030_SSW_FC | MMU030_SSW_RC | MMU030_SSW_FB | MMU030_SSW_RB | MMU030_SSW_RW | 7);
 	}
+	regs.wb3_status = 0;
+	regs.wb2_status = 0;
 	regs.mmu_fault_addr = addr;
 	if (fc & 1) {
 		regs.mmu_ssw = MMU030_SSW_DF | (MMU030_SSW_DF << 1);
+		if (!(mmu030_state[1] & MMU030_STATEFLAG1_LASTWRITE)) {
+			regs.wb2_status = mmu030fixupreg(0);
+			mmu030fixupmod(regs.wb2_status, 0, 0);
+			regs.wb3_status = mmu030fixupreg(1);
+			mmu030fixupmod(regs.wb3_status, 0, 1);
+		}
 	} else {
 		if (currprefs.cpu_compatible) {
 			if (regs.prefetch020_valid[1] != 1 && regs.prefetch020_valid[2] == 1) {
@@ -1800,10 +1826,6 @@ void mmu030_page_fault(uaecptr addr, bool read, int flags, uae_u32 fc)
 		} else {
 			regs.mmu_ssw = MMU030_SSW_FB | MMU030_SSW_RB;
 		}
-		if (!(mmu030_state[1] & MMU030_STATEFLAG1_LASTWRITE)) {
-			mmu030fixupreg(0);
-			mmu030fixupreg(1);
-		}
 	}
 	regs.mmu_ssw |= read ? MMU030_SSW_RW : 0;
 	regs.mmu_ssw |= flags;
@@ -2840,12 +2862,17 @@ void m68k_do_rte_mmu030 (uaecptr a7)
 		}
 
 		uae_u16 v = get_word_mmu030(a7 + 0x36);
-		idxsize = v & 0xff;
-		idxsize_done = (v >> 8) & 0xff;
+		idxsize = v & 0x0f;
+		idxsize_done = (v >> 4) & 0x0f;
 		for (int i = 0; i < idxsize_done + 1; i++) {
 			mmu030_ad_v[i].val = get_long_mmu030(a7 + 0x5c - (i + 1) * 4);
 		}
 
+		regs.wb2_status = v >> 8;
+		regs.wb3_status = mmu030_state_2 >> 8;
+		mmu030fixupmod(regs.wb2_status, 1, -1);
+		mmu030fixupmod(regs.wb3_status, 1, -1);
+
 		// did we have data fault but DF bit cleared?
 		if (ssw & (MMU030_SSW_DF << 1) && !(ssw & MMU030_SSW_DF)) {
 			// DF not set: mark access as done
@@ -3286,8 +3313,8 @@ void m68k_do_rte_mmu030c (uaecptr a7)
 		}
 
 		uae_u16 v = get_word_mmu030c(a7 + 0x36);
-		idxsize = v & 0xff;
-		idxsize_done = (v >> 8) & 0xff;
+		idxsize = v & 0x0f;
+		idxsize_done = (v >> 4) & 0x0f;
 		for (int i = 0; i < idxsize_done + 1; i++) {
 			mmu030_ad_v[i].val = get_long_mmu030c(a7 + 0x5c - (i + 1) * 4);
 		}
diff --git a/newcpu_common.cpp b/newcpu_common.cpp
index cbda5895..2d1b95ae 100644
--- a/newcpu_common.cpp
+++ b/newcpu_common.cpp
@@ -1436,10 +1436,10 @@ void Exception_build_stack_frame(uae_u32 oldpc, uae_u32 currpc, uae_u32 ssw, int
 		}
 		// version & internal information (We store index here)
 		m68k_areg(regs, 7) -= 2;
-		x_put_word(m68k_areg(regs, 7), (mmu030_idx & 0xff) | ((mmu030_idx_done & 0xff) << 8));
+		x_put_word(m68k_areg(regs, 7), (mmu030_idx & 0xf) | ((mmu030_idx_done & 0xf) << 4) | (regs.wb2_status << 8));
 		// 3* internal registers
 		m68k_areg(regs, 7) -= 2;
-		x_put_word(m68k_areg(regs, 7), mmu030_state[2]);
+		x_put_word(m68k_areg(regs, 7), mmu030_state[2] | (regs.wb3_status << 8));
 		m68k_areg(regs, 7) -= 2;
 		x_put_word(m68k_areg(regs, 7), regs.wb2_address); // = mmu030_state[1]
 		m68k_areg(regs, 7) -= 2;