Total rework of simulator for dev branch. Create separate thread for interrupt processes. Tick-accurate simulation of timers. Non-blocking character input for running in realtime mode. Decouple hardware sim from grbl code as much as possible. Expanded command line options. Provisions for cross-platform solution.

sim/eeprom.c

@@ -21,18 +21,75 @@
 */
 
 // These are never called in the simulator
+#include <stdio.h>
+#define MAX_EEPROM_SIZE 4096   //4KB EEPROM in Mega
+
+
+FILE* eeprom_create_empty_file(){
+  FILE* fp = fopen("EEPROM.DAT","w+b");
+  int i;
+  if (fp){
+	 for(i=0;i<MAX_EEPROM_SIZE;i++){
+		fputc(0,fp);
+	 }
+	 fseek(fp,0,SEEK_SET);
+  }
+  return fp;
+}
+
+
+FILE* eeprom_fp(){
+  static FILE* EEPROM_FP = NULL;
+  static int tried= 0;
+  if (!EEPROM_FP && !tried){
+	 tried = 1;
+	 EEPROM_FP = fopen("EEPROM.DAT","r+b");
+	 if (!EEPROM_FP) {
+		EEPROM_FP = eeprom_create_empty_file();
+	 }
+  }
+  return EEPROM_FP;
+}
+
+void eeprom_close(){
+  FILE* fp = eeprom_fp();
+  fclose(fp);
+}
 unsigned char eeprom_get_char( unsigned int addr ) {
-  return 0;
+
+  FILE* fp = eeprom_fp();
+  if (fseek(fp,addr,SEEK_SET)) { return 0; } //no such address
+  return fgetc(fp);
 }
 
 void eeprom_put_char( unsigned int addr, unsigned char new_value ) {
+  FILE* fp = eeprom_fp();
+  if (fseek(fp,addr,SEEK_SET)) { return; } //no such address
+  fputc(new_value, fp);
 }
 
+// Extensions added as part of Grbl 
+// KEEP IN SYNC WITH ../eeprom.c
+
 void memcpy_to_eeprom_with_checksum(unsigned int destination, char *source, unsigned int size) {
+  unsigned char checksum = 0;
+  for(; size > 0; size--) { 
+    checksum = (checksum << 1) || (checksum >> 7);
+    checksum += *source;
+    eeprom_put_char(destination++, *(source++)); 
+  }
+  eeprom_put_char(destination, checksum);
 }
 
 int memcpy_from_eeprom_with_checksum(char *destination, unsigned int source, unsigned int size) {
-  return 0;
+  unsigned char data, checksum = 0;
+  for(; size > 0; size--) { 
+    data = eeprom_get_char(source++);
+    checksum = (checksum << 1) || (checksum >> 7);
+    checksum += data;    
+    *(destination++) = data; 
+  }
+  return(checksum == eeprom_get_char(source));
 }
 
 // end of file