Merge pull request #99 from negativeExponent/libretro_updates

update

src/gb/GB.cpp

@@ -1065,10 +1065,13 @@ void gbWriteMemory(uint16_t address, uint8_t value)
             }
 #endif
         }
-
+#else
+        gbMemory[0xff02] = value;
+        if (gbSerialOn)
+            gbSerialTicks = GBSERIAL_CLOCK_TICKS;
+#endif
         gbSerialBits = 0;
         return;
-#endif
     }
 
     case 0x04: {
@@ -1893,11 +1896,11 @@ uint8_t gbReadMemory(uint16_t address)
             return gbMemory[0xff01];
         case 0x02:
             return (gbMemory[0xff02]);
-            case 0x03:
-                log("Undocumented Memory register read %04x PC=%04x\n",
+        case 0x03:
+            log("Undocumented Memory register read %04x PC=%04x\n",
                 address,
                 PC.W);
-                return 0xff;
+            return 0xff;
         case 0x04:
             return register_DIV;
         case 0x05:
@@ -5295,6 +5298,27 @@ void gbEmulate(int ticksToStop)
                 }
 #endif
             }
+#else
+        static int SIOctr = 0;
+        SIOctr++;
+        if (SIOctr % 5) {
+            if (gbSerialOn) {
+                if  (gbMemory[0xff02] & 1) {
+                    gbSerialTicks -= clockTicks;
+                    while (gbSerialTicks <= 0) {
+                        gbMemory[0xff01] = (gbMemory[0xff01] << 1) | 1;
+                        gbSerialBits++;
+                        if (gbSerialBits >= 8) {
+                            gbMemory[0xff02] &= 0x7f;
+                            gbMemory[0xff0f] = register_IF |= 8;
+                            gbSerialOn = 0;
+                            gbSerialBits = 0;
+                        } else
+                            gbSerialTicks += GBSERIAL_CLOCK_TICKS;
+                    }
+                }
+            }
+        }
 #endif
         // TODO: evaluate and fix this
         // On VBA-M (gb core running twice as fast?), each vblank is uses 35112 cycles.

src/gba/GBA.cpp

@@ -3038,11 +3038,27 @@ void CPUUpdateRegister(uint32_t address, uint16_t value)
         cpuNextEvent = cpuTotalTicks;
         break;
 
-#ifndef NO_LINK
     case COMM_SIOCNT:
+#ifndef NO_LINK
         StartLink(value);
+#else
+        if (!ioMem)
+            return;
+
+        if (value & 0x80) {
+            value &= 0xff7f;
+            if (value & 1 && (value & 0x4000)) {
+                UPDATE_REG(COMM_SIOCNT, 0xFF);
+                IF |= 0x80;
+                UPDATE_REG(0x202, IF);
+                value &= 0x7f7f;
+            }
+        }
+        UPDATE_REG(COMM_SIOCNT, value);
+#endif
         break;
 
+#ifndef NO_LINK
     case COMM_SIODATA8:
         UPDATE_REG(COMM_SIODATA8, value);
         break;
@@ -3057,11 +3073,19 @@ void CPUUpdateRegister(uint32_t address, uint16_t value)
         UPDATE_REG(0x132, value & 0xC3FF);
         break;
 
-#ifndef NO_LINK
+
     case COMM_RCNT:
+#ifndef NO_LINK
         StartGPLink(value);
+#else
+        if (!ioMem)
+            return;
+
+        UPDATE_REG(COMM_RCNT, value);
+#endif
         break;
 
+#ifndef NO_LINK
     case COMM_JOYCNT: {
         uint16_t cur = READ16LE(&ioMem[COMM_JOYCNT]);
 

src/libretro/Makefile

@@ -2,7 +2,7 @@ DEBUG=0
 TILED_RENDERING=0
 STATIC_LINKING=0
 FRONTEND_SUPPORTS_RGB565=1
-NO_LINK=0
+NO_LINK=1
 
 SPACE :=
 SPACE := $(SPACE) $(SPACE)

src/libretro/libretro.cpp

@@ -92,72 +92,6 @@ void (*dbgOutput)(const char* s, uint32_t addr);
 void (*dbgSignal)(int sig, int number);
 #endif
 
-// Dummy vars/funcs for serial io emulation without LINK communication related stuff
-#ifndef NO_LINK
-#include "../gba/GBALink.h"
-uint8_t gbSIO_SC;
-bool LinkIsWaiting;
-bool LinkFirstTime;
-bool EmuReseted;
-int winGbPrinterEnabled;
-bool gba_joybus_active = false;
-
-#define UPDATE_REG(address, value) WRITE16LE(((uint16_t*)&ioMem[address]), value)
-
-LinkMode GetLinkMode()
-{
-    return LINK_DISCONNECTED;
-}
-
-void StartGPLink(uint16_t value)
-{
-    if (!ioMem)
-        return;
-
-    UPDATE_REG(COMM_RCNT, value);
-}
-
-void LinkUpdate(int ticks)
-{
-}
-
-void StartLink(uint16_t siocnt)
-{
-/*    log("'s' siocnt = %04x\n", siocnt); */
-
-    if (!ioMem)
-        return;
-
-    if(siocnt & 0x80)
-    {
-        siocnt &= 0xff7f;
-        if(siocnt & 1 && (siocnt & 0x4000))
-        {
-            UPDATE_REG(COMM_SIOCNT, 0xFF);
-            IF |= 0x80;
-            UPDATE_REG(0x202, IF);
-            siocnt &= 0x7f7f;
-        }
-    }
-    UPDATE_REG(COMM_SIOCNT, siocnt);
-}
-
-void CheckLinkConnection()
-{
-}
-
-void gbInitLink()
-{
-   LinkIsWaiting = false;
-   LinkFirstTime = true;
-}
-
-uint16_t gbLinkUpdate(uint8_t b, int gbSerialOn) //used on external clock
-{
-   return (b << 8);
-}
-#endif
-
 #define GS555(x) (x | (x << 5) | (x << 10))
 uint16_t systemGbPalette[24] = {
     GS555(0x1f), GS555(0x15), GS555(0x0c), 0,