Implement most CPU instructions

core/vb.c

@@ -73,6 +73,7 @@ struct VB {
         /* Other state */
         uint32_t clocks;    /* Master clocks to wait */
         uint16_t code[2];   /* Instruction code units */
+        uint16_t exception; /* Exception cause code */
         uint16_t irq;       /* Interrupt request lines */
         int      length;    /* Instruction code length */
         uint32_t nextPC;    /* Address of next instruction */
@@ -83,27 +84,27 @@ struct VB {
     /* Other system state */
     uint8_t wram[0x10000]; /* System RAM */
 
-    /* Application callbacks */
+    /* Application data */
     vbOnExecute onExecute; /* CPU instruction execute */
     vbOnFetch   onFetch;   /* CPU instruction fetch */
     vbOnRead    onRead;    /* CPU instruction read */
     vbOnWrite   onWrite;   /* CPU instruction write */
+    void       *tag;       /* User data */
 };
 
 
 
 /***************************** Library Functions *****************************/
 
-/* Determine the lesser of two clocks figures */
-static uint32_t MinClocks(uint32_t a, uint32_t b) {
-    return a < b ? a : b;
-}
-
 /* Sign-extend an integer of variable width */
 static int32_t SignExtend(int32_t value, int32_t bits) {
+    #ifndef VB_SIGNED_PROPAGATE
         value &= ~((uint32_t) 0xFFFFFFFF << bits);
         bits   = (int32_t) 1 << (bits - (int32_t) 1);
         return (value ^ bits) - bits;
+    #else
+        return value << (32 - bits) >> (32 - bits);
+    #endif
 }
 
 
@@ -169,19 +170,6 @@ VBAPI int vbEmulateEx(VB **sims, int count, uint32_t *clocks) {
     return 0;
 }
 
-/* Retrieve a callback handler */
-VBAPI void* vbGetCallback(VB *sim, int id) {
-    switch (id) {
-        /*case VB_EXCEPTION: return *(void **) &sim->onException;*/
-        case VB_EXECUTE  : return *(void **) &sim->onExecute;
-        case VB_FETCH    : return *(void **) &sim->onFetch;
-        /*case VB_FRAME    : return *(void **) &sim->onFrame;*/
-        case VB_READ     : return *(void **) &sim->onRead;
-        case VB_WRITE    : return *(void **) &sim->onWrite;
-    }
-    return NULL;
-}
-
 /* Retrieve the game pack RAM buffer */
 VBAPI void* vbGetCartRAM(VB *sim, uint32_t *size) {
     if (size != NULL)
@@ -196,6 +184,16 @@ VBAPI void* vbGetCartROM(VB *sim, uint32_t *size) {
     return sim->cart.rom;
 }
 
+/* Retrieve the execute callback handle */
+VBAPI vbOnExecute vbGetExecuteCallback(VB *sim) {
+    return sim->onExecute;
+}
+
+/* Retrieve the fetch callback handle */
+VBAPI vbOnFetch vbGetFetchCallback(VB *sim) {
+    return sim->onFetch;
+}
+
 /* Retrieve the value of the program counter */
 VBAPI uint32_t vbGetProgramCounter(VB *sim) {
     return sim->cpu.pc;
@@ -206,11 +204,26 @@ VBAPI int32_t vbGetProgramRegister(VB *sim, int index) {
     return index < 1 || index > 31 ? 0 : sim->cpu.program[index];
 }
 
+/* Retrieve the read callback handle */
+VBAPI vbOnRead vbGetReadCallback(VB *sim) {
+    return sim->onRead;
+}
+
 /* Retrieve the value in a system register */
 VBAPI uint32_t vbGetSystemRegister(VB *sim, int index) {
     return index < 0 || index > 31 ? 0 : cpuGetSystemRegister(sim, index);
 }
 
+/* Retrieve a simulation's userdata pointer */
+VBAPI void* vbGetUserData(VB *sim) {
+    return sim->tag;
+}
+
+/* Retrieve the write callback handle */
+VBAPI vbOnWrite vbGetWriteCallback(VB *sim) {
+    return sim->onWrite;
+}
+
 /* Initialize a simulation instance */
 VBAPI VB* vbInit(VB *sim) {
     sim->cart.ram      = NULL;
@@ -241,6 +254,7 @@ VBAPI VB* vbReset(VB *sim) {
         sim->wram[x] = 0x00;
 
     /* CPU (normal) */
+    sim->cpu.exception = 0;
     sim->cpu.irq       = 0;
     sim->cpu.pc        = 0xFFFFFFF0;
     cpuSetSystemRegister(sim, VB_ECR, 0x0000FFF0, 1);
@@ -267,29 +281,6 @@ VBAPI VB* vbReset(VB *sim) {
     return sim;
 }
 
-/* Specify a new callback handler */
-VBAPI void* vbSetCallback(VB *sim, int id, void *callback) {
-    void  *prev   = NULL;
-    void **target = NULL;
-
-    /* Select callback by ID */
-    switch (id) {
-        /*case VB_EXCEPTION: target = (void **) &sim->onException; break;*/
-        case VB_EXECUTE  : target = (void **) &sim->onExecute  ; break;
-        case VB_FETCH    : target = (void **) &sim->onFetch    ; break;
-        /*case VB_FRAME    : target = (void **) &sim->onFrame    ; break;*/
-        case VB_READ     : target = (void **) &sim->onRead     ; break;
-        case VB_WRITE    : target = (void **) &sim->onWrite    ; break;
-    }
-
-    /* Retrieve current state and update new state */
-    if (target != NULL) {
-        prev    = *target;
-        *target = callback;
-    }
-    return prev;
-}
-
 /* Specify a game pak RAM buffer */
 VBAPI int vbSetCartRAM(VB *sim, void *sram, uint32_t size) {
     if (sram != NULL) {
@@ -312,6 +303,20 @@ VBAPI int vbSetCartROM(VB *sim, void *rom, uint32_t size) {
     return 0;
 }
 
+/* Specify a new execute callback handle */
+VBAPI vbOnExecute vbSetExecuteCallback(VB *sim, vbOnExecute callback) {
+    vbOnExecute prev = sim->onExecute;
+    sim->onExecute = callback;
+    return prev;
+}
+
+/* Specify a new fetch callback handle */
+VBAPI vbOnFetch vbSetFetchCallback(VB *sim, vbOnFetch callback) {
+    vbOnFetch prev = sim->onFetch;
+    sim->onFetch = callback;
+    return prev;
+}
+
 /* Specify a new value for the program counter */
 VBAPI uint32_t vbSetProgramCounter(VB *sim, uint32_t value) {
     sim->cpu.operation = CPU_FETCH;
@@ -325,17 +330,38 @@ VBAPI int32_t vbSetProgramRegister(VB *sim, int index, int32_t value) {
     return index < 1 || index > 31 ? 0 : (sim->cpu.program[index] = value);
 }
 
+/* Specify a new read callback handle */
+VBAPI vbOnRead vbSetReadCallback(VB *sim, vbOnRead callback) {
+    vbOnRead prev = sim->onRead;
+    sim->onRead = callback;
+    return prev;
+}
+
 /* Specify a new value for a system register */
 VBAPI uint32_t vbSetSystemRegister(VB *sim, int index, uint32_t value) {
     return index < 0 || index > 31 ? 0 :
         cpuSetSystemRegister(sim, index, value, 1);
 }
 
+/* Specify a new write callback handle */
+VBAPI vbOnWrite vbSetWriteCallback(VB *sim, vbOnWrite callback) {
+    vbOnWrite prev = sim->onWrite;
+    sim->onWrite = callback;
+    return prev;
+}
+
 /* Determine the size of a simulation instance */
 VBAPI size_t vbSizeOf() {
     return sizeof (VB);
 }
 
+/* Specify a simulation's userdata pointer */
+VBAPI void* vbSetUserData(VB *sim, void *tag) {
+    void *prev = sim->tag;
+    sim->tag = tag;
+    return prev;
+}
+
 /* Write a value to the memory bus */
 VBAPI int32_t vbWrite(VB *sim, uint32_t address, int type, int32_t value) {
     if (type < 0 || type > 4)

core/vb.h

@@ -44,11 +44,6 @@ extern "C" {
 #define VB_U16 3
 #define VB_S32 4
 
-/* CPU modes */
-#define VB_ACCURACY 0
-#define VB_DEBUG    1
-#define VB_WHOLE    2
-
 
 
 /*********************************** Types ***********************************/
@@ -72,18 +67,27 @@ VBAPI int      vbEmulateEx         (VB **sims, int count, uint32_t *clocks);
 VBAPI void*       vbGetCallback       (VB *sim, int id);
 VBAPI void*       vbGetCartRAM        (VB *sim, uint32_t *size);
 VBAPI void*       vbGetCartROM        (VB *sim, uint32_t *size);
+VBAPI vbOnExecute vbGetExecuteCallback(VB *sim);
+VBAPI vbOnFetch   vbGetFetchCallback  (VB *sim);
 VBAPI uint32_t    vbGetProgramCounter (VB *sim);
 VBAPI int32_t     vbGetProgramRegister(VB *sim, int index);
+VBAPI vbOnRead    vbGetReadCallback   (VB *sim);
 VBAPI uint32_t    vbGetSystemRegister (VB *sim, int index);
+VBAPI void*       vbGetUserData       (VB *sim);
+VBAPI vbOnWrite   vbGetWriteCallback  (VB *sim);
 VBAPI VB*         vbInit              (VB *sim);
 VBAPI int32_t     vbRead              (VB *sim, uint32_t address, int type);
 VBAPI VB*         vbReset             (VB *sim);
-VBAPI void*    vbSetCallback       (VB *sim, int index, void *callback);
 VBAPI int         vbSetCartRAM        (VB *sim, void *sram, uint32_t size);
 VBAPI int         vbSetCartROM        (VB *sim, void *rom, uint32_t size);
+VBAPI vbOnExecute vbSetExecuteCallback(VB *sim, vbOnExecute callback);
+VBAPI vbOnFetch   vbSetFetchCallback  (VB *sim, vbOnFetch callback);
 VBAPI uint32_t    vbSetProgramCounter (VB *sim, uint32_t value);
 VBAPI int32_t     vbSetProgramRegister(VB *sim, int index, int32_t value);
+VBAPI vbOnRead    vbSetReadCallback   (VB *sim, vbOnRead callback);
 VBAPI uint32_t    vbSetSystemRegister (VB *sim, int index, uint32_t value);
+VBAPI void*       vbSetUserData       (VB *sim, void *tag);
+VBAPI vbOnWrite   vbSetWriteCallback  (VB *sim, vbOnWrite callback);
 VBAPI size_t      vbSizeOf            ();
 VBAPI int32_t     vbWrite             (VB *sim, uint32_t address, int type, int32_t value);
 

makefile

@@ -41,14 +41,14 @@ core:
 #	GCC compilation control
 	@gcc core/vb.c -I core -c -o /dev/null \
         -Werror -std=c90 -Wall -Wextra -Wpedantic \
-        -D VB_LITTLE_ENDIAN -D VB_SIGNED_PROPAGATE
+        -D VB_LITTLE_ENDIAN -D VB_SIGNED_PROPAGATE -D VB_DIV_GENERIC
 #	Clang generic
 	@emcc core/vb.c -I core -c -o /dev/null \
         -Werror -std=c90 -Wall -Wextra -Wpedantic
 #	Clang compilation control
 	@emcc core/vb.c -I core -c -o /dev/null \
         -Werror -std=c90 -Wall -Wextra -Wpedantic \
-        -D VB_LITTLE_ENDIAN -D VB_SIGNED_PROPAGATE
+        -D VB_LITTLE_ENDIAN -D VB_SIGNED_PROPAGATE -D VB_DIV_GENERIC
 
 .PHONY: wasm
 wasm: