Update some

include/address_space.h

@@ -9,4 +9,6 @@ struct AddressSpace_s {
 
 typedef struct AddressSpace_s AddressSpace;
 
-AddressSpace create_address_space(int romSize, int ramSize);
+AddressSpace create_address_space(int romSize, int ramSize);
+int read_address_space(const AddressSpace *addressSpace, uint32_t address, const int n, void *dest);
+int write_address_space(const AddressSpace *addressSpace, uint32_t address, const int n, void *src);

include/cpu.h

@@ -9,4 +9,5 @@ struct CPU_s {
 
 typedef struct CPU_s CPU;
 
-CPU create_cpu(AddressSpace *addressSpace);
+CPU create_cpu(AddressSpace *addressSpace);
+int cycle(CPU *cpu);

include/instruction_executor.h

@@ -0,0 +1,3 @@
+#include "cpu.h"
+
+int execute_instruction_on_cpu(CPU *cpu, uint32_t instruction);

src/address_space.c

@@ -1,5 +1,6 @@
 #include <stdint.h>
 #include <stdio.h>
+#include <string.h>
 
 struct AddressSpace_s {
     // A pointer to a ROM array. The array can vary in length.
@@ -25,7 +26,7 @@ AddressSpace create_address_space(int romSize, int ramSize) {
     return addressSpace;
 }
 
-int read_address_space(const AddressSpace *addressSpace, uint32_t address, const int n, uint8_t *dest) {
+int read_address_space(const AddressSpace *addressSpace, uint32_t address, const int n, void *dest) {
     uint32_t romSize = addressSpace->romSize;
     uint32_t ramSize = addressSpace->ramSize;
 
@@ -34,9 +35,7 @@ int read_address_space(const AddressSpace *addressSpace, uint32_t address, const
             fprintf(stderr, "Reading %d bytes from %d will exceed ROM address space of %d\n", n, address, romSize); // TODO maybe move to perror
             return 1;
         } else {
-            for (int i=0; i<n; i++) {
-                dest[i] = addressSpace->rom[address + i];
-            }
+            memcpy(dest, addressSpace->rom + address, n);
         }
     } else if (address < romSize + ramSize) {
         if (address + n < romSize + ramSize) {
@@ -44,9 +43,7 @@ int read_address_space(const AddressSpace *addressSpace, uint32_t address, const
             return 1;
         } else {
             address -= romSize;
-            for (int i=0; i<n; i++) {
-                dest[i] = addressSpace->ram[address + i];
-            }
+            memcpy(dest, addressSpace->ram + address, n);
         }
 
     } else {
@@ -56,7 +53,7 @@ int read_address_space(const AddressSpace *addressSpace, uint32_t address, const
     return 0;
 }
 
-int write_address_space(const AddressSpace *addressSpace, uint32_t address, const int n, uint8_t *src) {
+int write_address_space(const AddressSpace *addressSpace, uint32_t address, const int n, void *src) {
     uint32_t romSize = addressSpace->romSize;
     uint32_t ramSize = addressSpace->ramSize;
 
@@ -65,9 +62,7 @@ int write_address_space(const AddressSpace *addressSpace, uint32_t address, cons
             fprintf(stderr, "Writing %d bytes to %d will exceed ROM address space of %d\n", n, address, romSize);
             return 1;
         } else {
-            for (int i=0; i<n; i++) {
-                addressSpace->rom[address + i] = src[i];
-            }
+            memcpy(addressSpace->rom + address, src, n);
         }
     } else if (address < romSize + ramSize) {
         if (address + n < romSize + ramSize) {
@@ -75,9 +70,7 @@ int write_address_space(const AddressSpace *addressSpace, uint32_t address, cons
             return 1;
         } else {
             address -= romSize;
-            for (int i=0; i<n; i++) {
-                addressSpace->ram[address + i] = src[i];
-            }
+            memcpy(addressSpace->ram + address, src, n);
         }
     } else {
         // TODO IO

src/cpu.c

@@ -1,5 +1,6 @@
 #include <stdint.h>
 #include "address_space.h"
+#include "instruction_executor.h"
 
 struct CPU_s {
     // [32] of 32bit (uint32_t) registers 
@@ -23,4 +24,17 @@ CPU create_cpu(AddressSpace *addressSpace) {
     cpu.addressSpace = addressSpace;
     
     return cpu;
+}
+
+int cycle(CPU *cpu) {
+    uint32_t instruction;
+    if (read_address_space(cpu->addressSpace, cpu->programCounter, 4, &instruction) != 0) {
+        return -1;
+    }
+
+    execute_instruction_on_cpu(cpu, instruction);
+
+    cpu->programCounter += 4;
+
+    return 0;
 }

src/instruction_executor.c

@@ -0,0 +1,9 @@
+#include "cpu.h"
+
+int execute_instruction_on_cpu(CPU *cpu, uint32_t instruction) {
+    AddressSpace *addressSpace = cpu->addressSpace;
+
+    // TODO
+
+    return 0;
+}

src/main.c

@@ -4,7 +4,7 @@
 #include "cpu.h"
 
 int main(int argc, char *argv[]) {
-    if (argc == 0) {
+    if (argc == 1) {
         fprintf(stderr, "Usage: criscv <binary program>\n");
         return 1;
     }

src/program_loader.c

@@ -5,7 +5,7 @@ int load_to_rom(const char filename[], AddressSpace *addressSpace) {
     FILE *file = fopen(filename, "rb");
     
     if (file == NULL) {
-        perror("Error opening file\n");
+        perror("Error opening file");
         return 1;
     }