Bus error/address error N/I bit, bus error helpers.

diff --git a/include/newcpu.h b/include/newcpu.h
index 1c2e481ed67a5d3aebe2022afc6d5e1ec90d088d..5f9232fb81b68f9410938fbd513157017599e881 100644 (file)
--- a/include/newcpu.h
+++ b/include/newcpu.h
@@ -573,6 +573,7 @@ extern int fpp_cond(int condition);
 
 extern void exception3_read(uae_u32 opcode, uaecptr addr);
 extern void exception3_write(uae_u32 opcode, uaecptr addr);
+extern void exception3_notinstruction(uae_u32 opcode, uaecptr addr);
 extern void exception3i (uae_u32 opcode, uaecptr addr);
 extern void exception3b (uae_u32 opcode, uaecptr addr, bool w, bool i, uaecptr pc);
 extern void exception2 (uaecptr addr, bool read, int size, uae_u32 fc);

diff --git a/newcpu.cpp b/newcpu.cpp
index f0f3f3d5f496c33f24def991d2840f30deca9698..17c74d37101c43b96a7aa611ee31eaa7236b2e55 100644 (file)
--- a/newcpu.cpp
+++ b/newcpu.cpp
@@ -56,9 +56,14 @@ static uaecptr last_addr_for_exception_3;
 /* Address that generated the exception */
 static uaecptr last_fault_for_exception_3;
 /* read (0) or write (1) access */
-static int last_writeaccess_for_exception_3;
+static bool last_writeaccess_for_exception_3;
 /* instruction (1) or data (0) access */
-static int last_instructionaccess_for_exception_3;
+static bool last_instructionaccess_for_exception_3;
+/* not instruction */
+static bool last_notinstruction_for_exception_3;
+/* set when writing exception stack frame */
+static int exception_in_exception;
+
 int mmu_enabled, mmu_triggered;
 int cpu_cycles;
 int bus_error_offset;
@@ -2142,12 +2147,17 @@ static void Exception_ce000 (int nr)
                regs.s = 1;
        }
        if (nr == 2 || nr == 3) { /* 2=bus error, 3=address error */
+               if ((m68k_areg(regs, 7) & 1) || exception_in_exception < 0) {
+                       cpu_halt (2);
+                       return;
+               }
                uae_u16 mode = (sv ? 4 : 0) | (last_instructionaccess_for_exception_3 ? 2 : 1);
                mode |= last_writeaccess_for_exception_3 ? 0 : 16;
+               mode |= last_notinstruction_for_exception_3 ? 8 : 0;
                // undocumented bits seem to contain opcode
                mode |= last_op_for_exception_3 & ~31;
                m68k_areg (regs, 7) -= 14;
-               /* fixme: bit3=I/N */
+               exception_in_exception = -1;
                x_put_word (m68k_areg (regs, 7) + 12, last_addr_for_exception_3);
                x_put_word (m68k_areg (regs, 7) + 8, regs.sr);
                x_put_word (m68k_areg (regs, 7) + 10, last_addr_for_exception_3 >> 16);
@@ -2163,6 +2173,11 @@ static void Exception_ce000 (int nr)
        if (currprefs.cpu_model == 68010) {
                // 68010 creates only format 0 and 8 stack frames
                m68k_areg (regs, 7) -= 8;
+               if (m68k_areg(regs, 7) & 1) {
+                       exception3_notinstruction(regs.ir, m68k_areg(regs, 7) + 4);
+                       return;
+               }
+               exception_in_exception = 1;
                x_put_word (m68k_areg (regs, 7) + 4, currpc); // write low address
                if (interrupt)
                        vector_nr = iack_cycle(nr);
@@ -2171,6 +2186,11 @@ static void Exception_ce000 (int nr)
                x_put_word (m68k_areg (regs, 7) + 6, vector_nr * 4);
        } else {
                m68k_areg (regs, 7) -= 6;
+               if (m68k_areg(regs, 7) & 1) {
+                       exception3_notinstruction(regs.ir, m68k_areg(regs, 7) + 4);
+                       return;
+               }
+               exception_in_exception = 1;
                x_put_word (m68k_areg (regs, 7) + 4, currpc); // write low address
                if (interrupt)
                        vector_nr = iack_cycle(nr);
@@ -2180,11 +2200,12 @@ static void Exception_ce000 (int nr)
 kludge_me_do:
        newpc = x_get_word (regs.vbr + 4 * vector_nr) << 16; // read high address
        newpc |= x_get_word (regs.vbr + 4 * vector_nr + 2); // read low address
+       exception_in_exception = 0;
        if (newpc & 1) {
                if (nr == 2 || nr == 3)
                        cpu_halt (2);
                else
-                       exception3_read(regs.ir, newpc);
+                       exception3_notinstruction(regs.ir, newpc);
                return;
        }
        m68k_setpc (newpc);
@@ -2554,6 +2575,19 @@ static void Exception_normal (int nr)
                if (currprefs.mmu_model)
                        mmu_set_super (regs.s != 0);
        }
+
+       if (m68k_areg(regs, 7) & 1) {
+               if (nr == 2 || nr == 3)
+                       cpu_halt (2);
+               else
+                       exception3_notinstruction(regs.ir, m68k_areg(regs, 7));
+               return;
+       }
+       if ((nr == 2 || nr == 3) && exception_in_exception < 0) {
+               cpu_halt (2);
+               return;
+       }
+
        if (currprefs.cpu_model > 68000) {
                currpc = exception_pc (nr);
                if (nr == 2 || nr == 3) {
@@ -2692,10 +2726,11 @@ static void Exception_normal (int nr)
                        // 68000 address error
                        uae_u16 mode = (sv ? 4 : 0) | (last_instructionaccess_for_exception_3 ? 2 : 1);
                        mode |= last_writeaccess_for_exception_3 ? 0 : 16;
+                       mode |= last_notinstruction_for_exception_3 ? 8 : 0;
                        // undocumented bits seem to contain opcode
                        mode |= last_op_for_exception_3 & ~31;
                        m68k_areg (regs, 7) -= 14;
-                       /* fixme: bit3=I/N */
+                       exception_in_exception = -1;
                        x_put_word (m68k_areg (regs, 7) + 0, mode);
                        x_put_long (m68k_areg (regs, 7) + 2, last_fault_for_exception_3);
                        x_put_word (m68k_areg (regs, 7) + 6, last_op_for_exception_3);
@@ -2711,11 +2746,12 @@ static void Exception_normal (int nr)
        x_put_word (m68k_areg (regs, 7), regs.sr);
 kludge_me_do:
        newpc = x_get_long (regs.vbr + 4 * vector_nr);
+       exception_in_exception = 0;
        if (newpc & 1) {
                if (nr == 2 || nr == 3)
                        cpu_halt (2);
                else
-                       exception3_write(regs.ir, newpc);
+                       exception3_read(regs.ir, newpc);
                return;
        }
        m68k_setpc (newpc);
@@ -6084,7 +6120,7 @@ uae_u8 *restore_mmu (uae_u8 *src)
 
 #endif /* SAVESTATE */
 
-static void exception3f (uae_u32 opcode, uaecptr addr, int writeaccess, int instructionaccess, uaecptr pc, bool plus2)
+static void exception3f (uae_u32 opcode, uaecptr addr, bool writeaccess, bool instructionaccess, bool notinstruction, uaecptr pc, bool plus2)
 {
        if (currprefs.cpu_model >= 68040)
                addr &= ~1;
@@ -6104,27 +6140,32 @@ static void exception3f (uae_u32 opcode, uaecptr addr, int writeaccess, int inst
        last_op_for_exception_3 = opcode;
        last_writeaccess_for_exception_3 = writeaccess;
        last_instructionaccess_for_exception_3 = instructionaccess;
+       last_notinstruction_for_exception_3 = notinstruction;
        Exception (3);
 #if EXCEPTION3_DEBUGGER
        activate_debugger();
 #endif
 }
 
+void exception3_notinstruction(uae_u32 opcode, uaecptr addr)
+{
+       exception3f (opcode, addr, true, false, true, 0xffffffff, false);
+}
 void exception3_read(uae_u32 opcode, uaecptr addr)
 {
-       exception3f (opcode, addr, false, 0, 0xffffffff, false);
+       exception3f (opcode, addr, false, 0, false, 0xffffffff, false);
 }
 void exception3_write(uae_u32 opcode, uaecptr addr)
 {
-       exception3f (opcode, addr, true, 0, 0xffffffff, false);
+       exception3f (opcode, addr, true, 0, false, 0xffffffff, false);
 }
 void exception3i (uae_u32 opcode, uaecptr addr)
 {
-       exception3f (opcode, addr, 0, 1, 0xffffffff, true);
+       exception3f (opcode, addr, 0, 1, false, 0xffffffff, true);
 }
 void exception3b (uae_u32 opcode, uaecptr addr, bool w, bool i, uaecptr pc)
 {
-       exception3f (opcode, addr, w, i, pc, true);
+       exception3f (opcode, addr, w, i, false, pc, true);
 }
 
 void exception2 (uaecptr addr, bool read, int size, uae_u32 fc)
@@ -6142,6 +6183,7 @@ void exception2 (uaecptr addr, bool read, int size, uae_u32 fc)
                last_writeaccess_for_exception_3 = read == 0;
                last_instructionaccess_for_exception_3 = (fc & 1) == 0;
                last_op_for_exception_3 = regs.opcode;
+               last_notinstruction_for_exception_3 = exception_in_exception != 0;
                THROW(2);
        }
 }