Implemented microcode reading.

emulator/src/components.c

@@ -22,6 +22,21 @@ word_t fetch_word(FILE *program, word_t addr) {
  return (uint16_t)((word & 0x00FF) << 8) | (uint16_t)(word >> 8);
 }
 
+/**
+ * Reads the signals at the given address (state) of the decode ROM.
+ * @param decode_rom The file stream for the decode ROM/microcode.
+ * @param addr The address of the signals to read.
+ * @return The signals stored at the given address.
+ */
+signals_t fetch_signals(FILE *decode_rom, uint8_t addr) {
+
+ fseek(decode_rom, addr * 2, SEEK_SET);
+
+ signals_t signals;
+ fread(&signals, sizeof(signals), 1, decode_rom);
+ return signals; // Don't care that this is little-endian, because signals are bit values
+}
+
 static word_t rotr(word_t a, word_t n) { return (a >> n) | (a << (sizeof(word_t) * 8 - n)); }
 static word_t rotl(word_t a, word_t n) { return (a << n) | (a >> (sizeof(word_t) * 8 - n)); }
 

emulator/src/components.h

@@ -105,8 +105,11 @@ typedef enum {
 
 /** Defines a single memory word. */
 typedef uint16_t word_t;
+/** Defines a set of internal signals. */
+typedef uint64_t signals_t;
 
 word_t fetch_word(FILE *program, word_t addr);
+signals_t fetch_signals(FILE *decode_rom, uint8_t addr);
 word_t alu(ALUOperation op, word_t a, word_t b, uint8_t *flags);
 
 #endif // _COMPONENTS_H_

emulator/src/main.c

@@ -3,33 +3,46 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-static char *filename = NULL;
 static uint16_t pc = 0;
 
 int main(int argc, char **argv) {
 
  // Get program to run
- if (argc != 2) {
- fprintf(stderr, "You must provide an input program file.\n");
+ if (argc != 3) {
+ fprintf(stderr, "You must provide microcode for the processor and an input program file.\n");
+ return EXIT_FAILURE;
+ }
+
+ // Open microcode
+ FILE *microcode = fopen(argv[1], "rb");
+ if (microcode == NULL) {
+ fprintf(stderr, "Could not open microcode file '%s'\n", argv[1]);
  return EXIT_FAILURE;
  }
 
  // Open program
- filename = argv[1];
- FILE *program = fopen(filename, "rb");
+ FILE *program = fopen(argv[2], "rb");
  if (program == NULL) {
- fprintf(stderr, "Could not open file '%s'.\n", filename);
+ fprintf(stderr, "Could not open program file '%s'.\n", argv[2]);
  return EXIT_FAILURE;
  }
 
  // Display program
  while (!feof(program) && !ferror(program)) {
  uint16_t word = fetch_word(program, pc);
- printf("original: %04x\n", word);
+ printf("%04x\n", word);
  pc++;
  }
 
+ uint8_t addr = 0;
+ while (!feof(microcode) && !ferror(microcode)) {
+ uint64_t signals = fetch_signals(microcode, addr);
+ printf("%016llx\n", signals);
+ addr++;
+ }
+
  // Close stream when done
+ fclose(microcode);
  fclose(program);
 
  return EXIT_SUCCESS;