End of day: working on vueRead()/VUE.read()

makefile

@@ -63,11 +63,14 @@ clean: clean_most
 .PHONY: core
 core:
 	@echo "  Checking native core library for style errors"
-	$(eval coreargs = -c -Isrc/core/include -Wall -Wextra \
+	$(eval coreargs = -c -Isrc/core/include -Werror -Wall -Wextra -Wpedantic \
         -fno-strict-aliasing -fsyntax-only src/core/vue.c)
 	@gcc -std=c90 $(coreargs)
+	@gcc -std=c90 -D VUE_BIGENDIAN $(coreargs)
 	@gcc -std=c99 $(coreargs)
+	@gcc -std=c99 -D VUE_BIGENDIAN $(coreargs)
 	@gcc -std=c11 $(coreargs)
+	@gcc -std=c11 -D VUE_BIGENDIAN $(coreargs)
 
 # Compile the Java desktop application
 .PHONY: desktop
@@ -161,5 +164,5 @@ win64: win64_pre native_common
 native_common:
 	@echo "  Building native module $(name)"
 	@$(prefix)gcc $(include) -Isrc/core/include $(gccargs) -s -shared -O2 \
-        -fno-strict-aliasing \
+        -fno-strict-aliasing -Werror \
         -o native/$(name)$(ext) src/desktop/native/native.c src/core/vue.c

src/core/bus.c

@@ -0,0 +1,47 @@
+/* This file is included through vue.c and cannot be built directly. */
+#ifdef VUEAPI
+
+/* Read a value directly from host memory */
+static int32_t busReadMemory(uint8_t *data, int type) {
+
+    /* Host memory is little-endian */
+    #ifndef VUE_BIGENDIAN
+        switch (type) {
+            case VUE_S8 : return *(int8_t   *)data;
+            case VUE_U8 : return *(uint8_t  *)data;
+            case VUE_S16: return *(int16_t  *)data;
+            case VUE_U16: return *(uint16_t *)data;
+            case VUE_S32: return *(int32_t  *)data;
+        }
+
+    /* Host memory is big-endian */
+    #else
+        switch (type) {
+            case VUE_S8 : return (int8_t  ) data[0];
+            case VUE_U8 : return (uint8_t ) data[0];
+            case VUE_S16: return (int16_t ) data[0] << 8 | data[1];
+            case VUE_U16: return (uint16_t) data[0] << 8 | data[1];
+            case VUE_S32: return (int32_t )
+                data[0] << 24 | data[1] << 16 | data[2] << 8 | data[3];
+        }
+    #endif
+
+    return 0; /* Unreachable, but the compiler doesn't know that */
+}
+
+/* Perform a read operation */
+static int32_t busReadValue(VUE *vue, uint32_t address, int type, vbool debug){
+    address &= ~TYPE_SIZES[type] + 1;
+    switch (address >> 24 & 7) {
+        case 3:           /* Unmapped */
+        case 4: return 0; /* Cartridge expansion */
+        case 5: return busReadMemory(&vue->wram[address & 8191], type);
+        case 6: return vue->sram == NULL ? 0 :
+            busReadMemory(&vue->sram[address & (vue->sram_size - 1)], type);
+        case 7: return vue->rom  == NULL ? 0 :
+            busReadMemory(&vue->rom [address & (vue->rom_size  - 1)], type);
+    }
+    return debug * 0; /* Unreachable */
+}
+
+#endif /* VUEAPI */

src/core/include/vue.h

@@ -15,6 +15,51 @@ extern "C" {
 
 
 
+/*****************************************************************************
+ *                                 Constants                                 *
+ *****************************************************************************/
+
+/* Boolean values */
+#define VUE_FALSE 0
+#define VUE_TRUE  1
+
+/* Memory access types */
+#define VUE_S8  0
+#define VUE_U8  1
+#define VUE_S16 2
+#define VUE_U16 3
+#define VUE_S32 4
+
+
+
+/*****************************************************************************
+ *                                   Types                                   *
+ *****************************************************************************/
+
+/* Boolean */
+typedef int vbool;
+
+/* Emulation state */
+typedef struct {
+    uint8_t *rom;           /* Cartridge ROM */
+    uint32_t rom_size;      /* Number of bytes in cartridge ROM */
+    uint8_t *sram;          /* Cartridge RAM */
+    uint32_t sram_size;     /* Number of bytes in cartridge RAM */
+    uint8_t  wram[0x10000]; /* System memory */
+} VUE;
+
+
+
+/*****************************************************************************
+ *                            Function Prototypes                            *
+ *****************************************************************************/
+
+VUEAPI void  vueInitialize(VUE *vue);
+VUEAPI vbool vueRead      (VUE *vue, uint32_t address, uint8_t *data, uint32_t length);
+VUEAPI vbool vueSetROM    (VUE *vue, uint8_t *rom, uint32_t size);
+
+
+
 #ifdef __cplusplus
 }
 #endif

src/core/vue.c

@@ -1,2 +1,76 @@
 #define VUEAPI
 #include <vue.h>
+
+
+
+/*****************************************************************************
+ *                                 Constants                                 *
+ *****************************************************************************/
+
+/* Memory access type sizes */
+static const int TYPE_SIZES[] = { 1, 1, 2, 2, 4 };
+
+
+
+/*****************************************************************************
+ *                            Component Includes                             *
+ *****************************************************************************/
+
+#include "bus.c"
+
+
+
+/*****************************************************************************
+ *                             Library Functions                             *
+ *****************************************************************************/
+
+/* Prepare an emulation state context for use */
+void vueInitialize(VUE *vue) {
+    vue->rom  = NULL;
+    vue->sram = NULL;
+}
+
+/* Perform a read operation */
+vbool vueRead(VUE *vue, uint32_t address, uint8_t *data, uint32_t length) {
+    uint32_t count; /* Bytes to read in one iteration */
+
+    /* Error checking */
+    if (
+        vue    == NULL ||
+        data   == NULL ||
+        length >  0x01000000
+    ) return VUE_FALSE;
+
+    /* Perform the operation */
+    for (; length > 0; address += count, length -= count, data += count) {
+
+        /* Determine the maximum number of bytes to process at once */
+        count = 0x01000000 - (address & 0x00FFFFFF);
+        if (count > length)
+            count = length;
+
+        /* Process by component */
+        switch (address >> 24 & 7) {
+            /* case 7: ROM, etc */
+        }
+
+    };
+    return VUE_TRUE;
+}
+
+/* Specify a new ROM buffer */
+vbool vueSetROM(VUE *vue, uint8_t *rom, uint32_t size) {
+
+    /* Error checking */
+    if (
+        vue == NULL ||
+        rom == NULL ||
+        size < 1024 || size > 0x01000000 ||
+        (size & (size - 1)) != 0
+    ) return VUE_FALSE;
+
+    /* Accept the new ROM buffer */
+    vue->rom      = rom;
+    vue->rom_size = size;
+    return VUE_TRUE;
+}

src/desktop/native/native.c

@@ -1,60 +1,81 @@
-#include <stddef.h>
-#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <jni.h>
+#include <vue.h>
 #include "vue_NativeVUE.h"
 
-// NativeVUE class lookup data
+
-static struct {
+
-    jclass   clazz;   // Handle to NativeVUE class
+///////////////////////////////////////////////////////////////////////////////
-    jfieldID pointer; // ID of NativeVUE.pointer field
+//                                 Constants                                 //
-} NativeVUE;
+///////////////////////////////////////////////////////////////////////////////
+
+// Memory access type sizes
+static const int TYPE_SIZES[] = { 1, 1, 2, 2, 4 };
+
+
+
+///////////////////////////////////////////////////////////////////////////////
+//                                   Types                                   //
+///////////////////////////////////////////////////////////////////////////////
 
 // Core context state type
 typedef struct {
-    uint8_t *rom;
+    VUE vue;
-    uint32_t rom_size;
 } CORE;
 
+
+
+///////////////////////////////////////////////////////////////////////////////
+//                            Internal Functions                             //
+///////////////////////////////////////////////////////////////////////////////
+
+// Determine the field ID of NativeVUE.pointer
+static jfieldID GetPointerID(JNIEnv *env, jobject vue) {
+    return (*env)->GetFieldID(env,
+        (*env)->GetObjectClass(env, vue), "pointer", "[B");
+}
+
 // Retrieve the handle to a NativeVUE's core context
 static CORE* GetCore(JNIEnv *env, jobject vue) {
     jbyteArray pointer =
-        (*env)->GetObjectField(env, vue, NativeVUE.pointer);
+        (*env)->GetObjectField(env, vue, GetPointerID(env, vue));
     jbyte     *elems   = (*env)->GetByteArrayElements(env, pointer, NULL);
     CORE      *core    = *(CORE **)elems;
     (*env)->ReleaseByteArrayElements(env, pointer, elems, 0);
     return core;
 }
 
+
+
+///////////////////////////////////////////////////////////////////////////////
+//                             Method Functions                              //
+///////////////////////////////////////////////////////////////////////////////
+
 // Native constructor
 JNIEXPORT void JNICALL Java_vue_NativeVUE_construct
   (JNIEnv *env, jobject vue) {
 
-    // Initialize the class data
-    if (NativeVUE.clazz == NULL) {
-        NativeVUE.clazz   = (*env)->GetObjectClass(env, vue);
-        NativeVUE.pointer =
-            (*env)->GetFieldID(env, NativeVUE.clazz, "pointer", "[B");
-    }
-
     // Produce and initialize s new core context
     CORE *core = calloc(sizeof (CORE), 1);
-    core->rom  = calloc(1024, 1);
+    vueInitialize(&core->vue);
+    vueSetROM(&core->vue, calloc(1024, 1), 1024);
 
     // Encode the context handle into a byte array
     jbyteArray pointer = (*env)->NewByteArray(env, sizeof (void *));
     jbyte     *elems   = (*env)->GetByteArrayElements(env, pointer, NULL);
     *(CORE **)elems = core;
     (*env)->ReleaseByteArrayElements(env, pointer, elems, 0);
-    (*env)->SetObjectField(env, vue, NativeVUE.pointer, pointer);
+    (*env)->SetObjectField(env, vue, GetPointerID(env, vue), pointer);
 }
 
 // Release any used resources
 JNIEXPORT void JNICALL Java_vue_NativeVUE_dispose
   (JNIEnv *env, jobject vue) {
     CORE *core = GetCore(env, vue);
-    free(core->rom);
+    free(core->vue.rom);
+    if (core->vue.sram != NULL)
+        free(core->vue.sram);
     free(core);
 }
 
@@ -62,9 +83,9 @@ JNIEXPORT void JNICALL Java_vue_NativeVUE_dispose
 JNIEXPORT jbyteArray JNICALL Java_vue_NativeVUE_getROM
   (JNIEnv *env, jobject vue) {
     CORE *core = GetCore(env, vue);
-    jbyteArray ret   = (*env)->NewByteArray(env, (jint) core->rom_size);
+    jbyteArray ret   = (*env)->NewByteArray(env, (jint) core->vue.rom_size);
     jbyte     *elems = (*env)->GetByteArrayElements(env, ret, NULL);
-    memcpy(elems, core->rom, core->rom_size);
+    memcpy(elems, core->vue.rom, core->vue.rom_size);
     (*env)->ReleaseByteArrayElements(env, ret, elems, 0);
     return ret;
 }
@@ -75,23 +96,50 @@ JNIEXPORT jboolean JNICALL Java_vue_NativeVUE_isNative
     return JNI_TRUE;
 }
 
+// Perform a read access
+JNIEXPORT jboolean JNICALL Java_vue_NativeVUE_read
+  (JNIEnv *env, jobject vue, jint address, jbyteArray data, jint offset,
+        jint length) {
+
+    // Error checking
+    if (
+        data   == NULL ||
+        offset <  0    ||
+        length <  0    ||
+        length <  0    || length > 0x01000000 ||
+        offset + length > (*env)->GetArrayLength(env, data)
+    ) return JNI_FALSE;
+
+    // Perform the operation
+    CORE  *core  = GetCore(env, vue);
+    jbyte *elems = (*env)->GetByteArrayElements(env, data, NULL);
+    vueRead(&core->vue, address, &elems[offset], length);
+    (*env)->ReleaseByteArrayElements(env, data, elems, 0);
+    return JNI_TRUE;
+}
+
 // Provide new ROM data
 JNIEXPORT jboolean JNICALL Java_vue_NativeVUE_setROM
   (JNIEnv *env, jobject vue, jbyteArray data, jint offset, jint length) {
 
     // Error checking
-    if (data == NULL || offset < 0 || length < 1024 ||
+    if (
-        offset + length > (*env)->GetArrayLength(env, data) ||
+        data == NULL  ||
-        (length & length - 1) != 0)
+        offset < 0    ||
-        return JNI_FALSE;
+        length < 1024 || length > 0x01000000 ||
+        (length & length - 1) != 0           ||
+        offset + length > (*env)->GetArrayLength(env, data)
+    ) return JNI_FALSE;
 
     // Accept the new ROM data
-    CORE *core = GetCore(env, vue);
+    uint8_t *rom   = calloc(length, 1);
-    free(core->rom);
+    jbyte   *elems = (*env)->GetByteArrayElements(env, data, NULL);
-    core->rom = calloc(length, 1);
+    memcpy(rom, &elems[offset], length);
-    jbyte *elems = (*env)->GetByteArrayElements(env, data, NULL);
-    memcpy(core->rom, &elems[offset], length);
     (*env)->ReleaseByteArrayElements(env, data, elems, 0);
-    core->rom_size = (uint32_t) length;
+
+    // Transfer the ROM data to the emulation state
+    CORE *core = GetCore(env, vue);
+    free(core->vue.rom);
+    vueSetROM(&core->vue, rom, length);
     return JNI_TRUE;
 }

src/desktop/vue/JavaVUE.java

@@ -4,7 +4,17 @@ package vue;
 class JavaVUE extends VUE {
 
     // Instance fields
-    private byte[] rom; // Cartridge ROM
+    private byte[] rom;  // Cartridge ROM
+    private byte[] sram; // Cartridge SRAM
+
+
+
+    ///////////////////////////////////////////////////////////////////////////
+    //                               Constants                               //
+    ///////////////////////////////////////////////////////////////////////////
+
+    // Memory access type sizes
+    private static final int[] TYPE_SIZES = { 1, 1, 2, 2, 4 };
 
 
 
@@ -14,7 +24,6 @@ class JavaVUE extends VUE {
 
     // Default constructor
     JavaVUE() {
-        rom = new byte[1024];
     }
 
 
@@ -29,7 +38,7 @@ class JavaVUE extends VUE {
     // Retrieve a copy of the ROM data
     public byte[] getROM() {
         var ret = new byte[rom.length];
-        System.arraycopy(rom, 0, ret, 0, rom.length);
+        System.arraycopy(rom, 0, ret, 0, ret.length);
         return ret;
     }
 
@@ -38,13 +47,33 @@ class JavaVUE extends VUE {
         return false;
     }
 
+    // Perform a read operation
+    public boolean read(int address, byte[] data, int offset, int length) {
+
+        // Error checking
+        if (data   == null ||
+            offset <  0    ||
+            length <  0    ||
+            length <  0    || length > 0x01000000 ||
+            offset + length > data.length
+        ) return false;
+
+        // Perform the operation
+
+        return true;
+    }
+
     // Provide new ROM data
     public boolean setROM(byte[] data, int offset, int length) {
 
         // Error checking
-        if (data == null || offset < 0 || length < 1024 ||
+        if (
-            offset + length > data.length || (length & length - 1) != 0)
+            data == null  ||
-            return false;
+            offset < 0    ||
+            length < 1024 || length > 0x01000000 ||
+            (length & length - 1) != 0           ||
+            offset + length > data.length
+        ) return false;
 
         // Accept the new ROM data
         rom = new byte[length];

src/desktop/vue/NativeVUE.java

@@ -32,6 +32,10 @@ class NativeVUE extends VUE {
     // Determine whether the context is native-backed
     public native boolean isNative();
 
+    // Perform a read operation
+    public native boolean read(int address, byte[] data, int offset,
+        int length);
+
     // Provide new ROM data
     public native boolean setROM(byte[] data, int offset, int length);
 

src/desktop/vue/VUE.java

@@ -8,6 +8,19 @@ public abstract class VUE {
 
 
 
+    ///////////////////////////////////////////////////////////////////////////
+    //                               Constants                               //
+    ///////////////////////////////////////////////////////////////////////////
+
+    // Memory access types 
+    public static final int S8  = 0;
+    public static final int U8  = 1;
+    public static final int S16 = 2;
+    public static final int U16 = 3;
+    public static final int S32 = 4;
+
+
+
     ///////////////////////////////////////////////////////////////////////////
     //                               Static Methods                          //
     ///////////////////////////////////////////////////////////////////////////
@@ -48,6 +61,10 @@ public abstract class VUE {
     // Determine whether the context is native-backed
     public abstract boolean isNative();
 
+    // Perform a read operation
+    public abstract boolean read(int address, byte[] data, int offset,
+        int length);
+
     // Provide new ROM data
     public abstract boolean setROM(byte[] data, int offset, int length);