From: Toni Wilen <twilen@winuae.net>
Date: Sat, 16 Feb 2019 11:10:23 +0000 (+0200)
Subject: 68030 MMU short bus error stack frame preparations.
X-Git-Tag: 4200~56
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=75a81a573941aa58430ac19e545eebcaa2ff06cc;p=francis%2Fwinuae.git

68030 MMU short bus error stack frame preparations.
---

diff --git a/cpummu30.cpp b/cpummu30.cpp
index 111f0192..e8a7f505 100644
--- a/cpummu30.cpp
+++ b/cpummu30.cpp
@@ -2742,35 +2742,58 @@ void m68k_do_rte_mmu030 (uaecptr a7)
 	else
 		get_word_mmu030(a7 + 32 - 2);
 
-	// Internal register, our opcode storage area
-	uae_u32 oc = get_long_mmu030(a7 + 0x14);
-	// Data output buffer
-	uae_u32 mmu030_data_buffer_out_v = get_long_mmu030(a7 + 0x18);
-	// get_disp_ea_020
-	uae_u32 mmu030_disp_store_0 = get_long_mmu030(a7 + 0x1c);
-	uae_u32 mmu030_disp_store_1 = get_long_mmu030(a7 + 0x1c + 4);
-	// Internal register, misc flags
-	uae_u32 ps = get_long_mmu030(a7 + 0x28);
-	// Data buffer
-	uae_u32 mmu030_data_buffer_in_v = get_long_mmu030(a7 + 0x2c);;
+	// Rerun "mmu030_opcode" using restored state.
+	mmu030_retry = true;
 
-	uae_u32 mmu030_opcode_v = (ps & 0x80000000) ? -1U : (oc & 0xffff);
-	// Misc state data
-	uae_u32 mmu030_state_0 = get_word_mmu030(a7 + 0x30);
-	uae_u32 mmu030_state_1 = get_word_mmu030(a7 + 0x32);
-	uae_u32 mmu030_state_2 = get_word_mmu030(a7 + 0x34);
+	if (frame == 0xa) {
 
-	uae_u32 mmu030_fmovem_store_0 = 0;
-	uae_u32 mmu030_fmovem_store_1 = 0;
-	if (mmu030_state[1] & MMU030_STATEFLAG1_FMOVEM) {
-		mmu030_fmovem_store_0 = get_long_mmu030(a7 + 0x5c - (7 + 1) * 4);
-		mmu030_fmovem_store_1 = get_long_mmu030(a7 + 0x5c - (8 + 1) * 4);
-	}
+		// A-frame only in non-prefetch mode and only when
+		// instruction's first word fetch caused access fault.
+		// mmu030_opcode_v is always -1 here.
+		if ((ssw & MMU030_SSW_FB) && !(ssw & MMU030_SSW_RB)) {
+			uae_u16 stageb = get_word_mmu030(a7 + 0x0e);
+			mmu030_opcode_stageb = stageb;
+			write_log(_T("Software fixed stage B! opcode = %04x\n"), stageb);
+		}
+		mmu030_opcode = -1;
 
-	// Rerun "mmu030_opcode" using restored state.
-	mmu030_retry = true;
+		m68k_areg(regs, 7) += 32;
+		regs.sr = sr;
+		MakeFromSR_T0();
+		if (pc & 1) {
+			exception3i(0x4E73, pc);
+			return;
+		}
+		m68k_setpci(pc);
 
-	if (frame == 0xb) {
+
+	} else if (frame == 0xb) {
+
+		// get_disp_ea_020
+		uae_u32 mmu030_disp_store_0 = get_long_mmu030(a7 + 0x1c);
+		uae_u32 mmu030_disp_store_1 = get_long_mmu030(a7 + 0x1c + 4);
+		// Internal register, misc flags
+		uae_u32 ps = get_long_mmu030(a7 + 0x28);
+		// Data buffer
+		uae_u32 mmu030_data_buffer_in_v = get_long_mmu030(a7 + 0x2c);;
+		// Misc state data
+		uae_u32 mmu030_state_0 = get_word_mmu030(a7 + 0x30);
+		uae_u32 mmu030_state_1 = get_word_mmu030(a7 + 0x32);
+		uae_u32 mmu030_state_2 = get_word_mmu030(a7 + 0x34);
+
+		// Internal register, our opcode storage area
+		uae_u32 oc = get_long_mmu030(a7 + 0x14);
+		// Data output buffer
+		uae_u32 mmu030_data_buffer_out_v = get_long_mmu030(a7 + 0x18);
+
+		uae_u32 mmu030_opcode_v = (ps & 0x80000000) ? -1U : (oc & 0xffff);
+
+		uae_u32 mmu030_fmovem_store_0 = 0;
+		uae_u32 mmu030_fmovem_store_1 = 0;
+		if (mmu030_state[1] & MMU030_STATEFLAG1_FMOVEM) {
+			mmu030_fmovem_store_0 = get_long_mmu030(a7 + 0x5c - (7 + 1) * 4);
+			mmu030_fmovem_store_1 = get_long_mmu030(a7 + 0x5c - (8 + 1) * 4);
+		}
 
 		uae_u16 idxsize = get_word_mmu030 (a7 + 0x36);
 		for (int i = 0; i < idxsize + 1; i++) {
@@ -2928,8 +2951,6 @@ void m68k_do_rte_mmu030 (uaecptr a7)
 		}
 #endif
 
-	} else {
-		m68k_areg (regs, 7) += 32;
 	}
 }
 
@@ -3331,6 +3352,16 @@ void m68k_do_rte_mmu030c (uaecptr a7)
 		}
 
 	} else {
+
 		m68k_areg (regs, 7) += 32;
+
+		regs.sr = sr;
+		MakeFromSR_T0();
+		if (pc & 1) {
+			exception3i(0x4E73, pc);
+			return;
+		}
+		m68k_setpci(pc);
+
 	}
 }
diff --git a/gencpu.cpp b/gencpu.cpp
index 84831131..3cb38b42 100644
--- a/gencpu.cpp
+++ b/gencpu.cpp
@@ -4025,10 +4025,10 @@ static void gen_opcode (unsigned int opcode)
 				printf ("\t\telse if (frame == 0x9) { m68k_areg (regs, 7) += offset + 12; break; }\n");
 				if (using_mmu == 68030) {
 					if (using_prefetch_020) {
-						printf ("\t\telse if (frame == 0xa) { m68k_do_rte_mmu030c (a); break; }\n");
+						printf ("\t\telse if (frame == 0xa) { m68k_do_rte_mmu030c (a); goto %s; }\n", endlabelstr);
 					    printf ("\t\telse if (frame == 0xb) { m68k_do_rte_mmu030c (a); goto %s; }\n", endlabelstr);
 					} else {
-						printf ("\t\telse if (frame == 0xa) { m68k_do_rte_mmu030 (a); break; }\n");
+						printf ("\t\telse if (frame == 0xa) { m68k_do_rte_mmu030 (a); goto %s; }\n", endlabelstr);
 					    printf ("\t\telse if (frame == 0xb) { m68k_do_rte_mmu030 (a); goto %s; }\n", endlabelstr);
 					}
 				} else {
diff --git a/newcpu.cpp b/newcpu.cpp
index 870b441f..ff94ed94 100644
--- a/newcpu.cpp
+++ b/newcpu.cpp
@@ -3362,7 +3362,12 @@ static void Exception_mmu030 (int nr, uaecptr oldpc)
 		m68k_areg (regs, 7) = regs.isp;
         Exception_build_stack_frame (oldpc, currpc, regs.mmu_ssw, nr, 0x1);
     } else if (nr == 2) {
-        Exception_build_stack_frame (oldpc, currpc, regs.mmu_ssw, nr,  0xB);
+		if (0) {
+			// not that simple
+			Exception_build_stack_frame(oldpc, currpc, regs.mmu_ssw, nr, 0xA);
+		} else {
+			Exception_build_stack_frame(oldpc, currpc, regs.mmu_ssw, nr, 0xB);
+		}
     } else if (nr == 3) {
 		regs.mmu_fault_addr = last_fault_for_exception_3;
 		mmu030_state[0] = mmu030_state[1] = 0;
@@ -5996,7 +6001,7 @@ insretry:
 
 		} CATCH (prb) {
 
-			if (mmu030_opcode == -1 && currprefs.cpu_compatible) {
+			if (mmu030_opcode == -1) {
 				// full prefetch fill access fault
 				// TODO: this should create shorter A-frame
 				mmufixup[0].reg = -1;