memory revamp described, endianness checked

equi.c

@@ -34,6 +34,9 @@
 #define cputc(c) (putchar(c))
 #endif
 
+/* also, do our best to ensure short-packed value storage in our virtual RAM */
+#pragma pack(2)
+
 /* Definitions section */
 
 #define EQUI_VER "0.0.1"
@@ -312,6 +315,12 @@ ushort crc16(const uchar* data_p, uchar length) {
   return crc;
 }
 
+/* Short endianness conversion helper */
+
+ushort tobig(ushort val) {
+  return (val>>8)|((val&255)<<8);
+}
+
 /* Persistent operation handler */
 
 ushort persistOp(FILE *pfd, ushort maddr, ushort dataLen, ushort adl, ushort adh, uchar isWrite) {
@@ -587,6 +596,9 @@ void equi_main_loop() {
 
 int main(int argc, char* argv[]) {
   uchar instr, bc, smode = 0;
+  /* detect host endianness */
+  int host_islittle = 1;
+  host_islittle = (*((char *)&host_islittle) == 1) ? 1 : 0;
   /* _attempt_ to disable buffering for char input/output */
 #if !defined __CC65__ && !defined __TINYC__
   setvbuf(stdin, NULL, _IONBF, 0);
@@ -622,6 +634,15 @@ int main(int argc, char* argv[]) {
       ram.clt_start, ram.gpd_start - ram.clt_start, ram.gpd_start, ram.cmd_start - ram.gpd_start, ram.cmd_start, ram.cmd_size);
   }
 
+  /* now, if necessary, convert the values that could be read by the program to big-endian */
+  if(host_islittle) {
+    ram.stack_size = tobig(ram.stack_size);
+    ram.clt_start = tobig(ram.clt_start);
+    ram.gpd_start = tobig(ram.gpd_start);
+    ram.cmd_start = tobig(ram.cmd_start);
+    ram.cmd_size = tobig(ram.cmd_size);
+  }
+
   while(1) { /* Now, we're in the command mode loop */
     instr = cgetc(); /* Fetch the next instruction from the keyboard/stdin */
     if(instr == 0xFFU || instr == 0U) /* exit on zero byte */