cd: fix breakage in comm detection

pico/cd/mcd.c

@@ -45,8 +45,6 @@ PICO_INTERNAL void PicoPowerMCD(void)
   Pico_mcd->m.state_flags = PCD_ST_S68K_RST;
   Pico_mcd->m.busreq = 2;     // busreq on, s68k in reset
   Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode, m68k access
-  Pico_mcd->s68k_regs[6] = 0xff;
-  Pico_mcd->s68k_regs[7] = 0xff;
   memset(Pico_mcd->bios + 0x70, 0xff, 4);
 }
 
@@ -265,7 +263,9 @@ static void SekSyncM68k(void);
 static inline void pcd_run_cpus_normal(int m68k_cycles)
 {
   SekCycleAim += m68k_cycles;
-  if (Pico_mcd->m.m68k_poll_cnt >= 16 && !SekShouldInterrupt()) {
+  if (SekShouldInterrupt())
+    Pico_mcd->m.m68k_poll_cnt = 0;
+  else if (Pico_mcd->m.m68k_poll_cnt >= 16) {
     int s68k_left = pcd_sync_s68k(SekCycleAim, 1);
     if (s68k_left <= 0) {
       elprintf(EL_CDPOLL, "m68k poll [%02x] x%d @%06x",
@@ -287,6 +287,8 @@ static inline void pcd_run_cpus_lockstep(int m68k_cycles)
     SekSyncM68k();
     pcd_sync_s68k(SekCycleAim, 0);
   } while (CYCLES_GT(target, SekCycleAim));
+
+  SekCycleAim = target;
 }
 
 #define PICO_CD

pico/cd/memory.c

@@ -72,16 +72,15 @@ static void remap_word_ram(u32 r3);
 #define POLL_LIMIT 16
 #define POLL_CYCLES 124
 
-u32 m68k_comm_check(u32 a, u32 d)
+void m68k_comm_check(u32 a)
 {
   pcd_sync_s68k(SekCyclesDone(), 0);
   if (a != Pico_mcd->m.m68k_poll_a) {
     Pico_mcd->m.m68k_poll_a = a;
     Pico_mcd->m.m68k_poll_cnt = 0;
-    return d;
+    return;
   }
   Pico_mcd->m.m68k_poll_cnt++;
-  return d;
 }
 
 #ifndef _ASM_CD_MEMORY_C
@@ -97,9 +96,10 @@ static u32 m68k_reg_read16(u32 a)
         | Pico_mcd->m.busreq;
       goto end;
     case 2:
+      m68k_comm_check(a);
       d = (Pico_mcd->s68k_regs[a]<<8) | (Pico_mcd->s68k_regs[a+1]&0xc7);
       elprintf(EL_CDREG3, "m68k_regs r3: %02x @%06x", (u8)d, SekPc);
-      goto end_comm;
+      goto end;
     case 4:
       d = Pico_mcd->s68k_regs[4]<<8;
       goto end;
@@ -123,17 +123,15 @@ static u32 m68k_reg_read16(u32 a)
 
   if (a < 0x30) {
     // comm flag/cmd/status (0xE-0x2F)
+    m68k_comm_check(a);
     d = (Pico_mcd->s68k_regs[a]<<8) | Pico_mcd->s68k_regs[a+1];
-    goto end_comm;
+    goto end;
   }
 
   elprintf(EL_UIO, "m68k_regs FIXME invalid read @ %02x", a);
 
 end:
   return d;
-
-end_comm:
-  return m68k_comm_check(a, d);
 }
 #endif
 

pico/cd/memory_arm.s

@@ -174,16 +174,14 @@ m_m68k_read8_r02:
     add     r1, r1, #0x110000
     ldrb    r0, [r1, #2]
     bx      lr
-m_m68k_read8_r03:                     @ FIXME: sync with C
-    add     r2, r1, #0x110000
-    ldrb    r1, [r2, #3]
-    add     r2, r2, #0x002200
-    ldr     r2, [r2, #4]
-    and     r1, r1, #0xc7
-    tst     r2, #2                    @ DMNA pending?
-    bicne   r1, r1, #1
-    orrne   r1, r1, #2
-    b       m68k_comm_check
+m_m68k_read8_r03:
+    add     r1, r1, #0x110000
+    push    {r1, lr}
+    bl      m68k_comm_check
+    pop     {r1, lr}
+    ldrb    r0, [r1, #3]
+    and     r0, r0, #0xc7
+    bx      lr
 m_m68k_read8_r04:
     add     r1, r1, #0x110000
     ldrb    r0, [r1, #4]
@@ -216,11 +214,15 @@ m_m68k_read8_r0d:
     bx      lr
 m_m68k_read8_hi:
     cmp     r0, #0x30
-    movge   r0, #0
-    bxeq    lr
     add     r1, r1, #0x110000
-    ldrb    r1, [r1, r0]
-    b       m68k_comm_check
+    movge   r0, #0
+    bxge    lr
+    add     r1, r0
+    push    {r1, lr}
+    bl      m68k_comm_check
+    pop     {r1, lr}
+    ldrb    r0, [r1]
+    bx      lr
 
 
 @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@ -269,18 +271,16 @@ m_m68k_read16_r00:
     and     r0, r0, #0x04000000       @ we need irq2 mask state
     orr     r0, r1, r0, lsr #11
     bx      lr
-m_m68k_read16_r02:                    @ FIXME: out of sync from C
-    add     r3, r1, #0x110000
-    ldrb    r1, [r3, #2]
-    ldrb    r2, [r3, #3]
-    add     r3, r3, #0x002200
-    ldr     r3, [r3, #4]
+m_m68k_read16_r02:
+    add     r1, r1, #0x110000
+    push    {r1, lr}
+    bl      m68k_comm_check
+    pop     {r1, lr}
+    ldrb    r2, [r1, #3]
+    ldrb    r0, [r1, #2]
     and     r2, r2, #0xc7
-    orr     r1, r2, r1, lsl #8
-    tst     r3, #2                    @ DMNA pending?
-    bicne   r1, r1, #1
-    orrne   r1, r1, #2
-    b       m68k_comm_check
+    orr     r0, r2, r0, lsl #8
+    bx      lr
 m_m68k_read16_r04:
     add     r1, r1, #0x110000
     ldrb    r0, [r1, #4]
@@ -300,14 +300,19 @@ m_m68k_read16_r0c:
     bx      lr
 m_m68k_read16_hi:
     cmp     r0, #0x30
-    addlt   r1, r1, #0x110000
-    ldrlth  r1, [r1, r0]
+    add     r1, r1, #0x110000
     movge   r0, #0
     bxge    lr
-    mov     r2, r1, lsr #8
-    and     r1, r1, #0xff
-    orr     r1, r2, r1, lsl #8
-    b       m68k_comm_check
+
+    add     r1, r0, r1
+    push    {r1, lr}
+    bl      m68k_comm_check
+    pop     {r0, lr}
+    ldrh    r0, [r0]
+    mov     r1, r0, lsr #8
+    and     r0, r0, #0xff
+    orr     r0, r1, r0, lsl #8
+    bx      lr
 
 
 @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@