modeling of a program ROM

assets/bios/bios_source.js

@@ -0,0 +1,80 @@
+println("TERRAN Megatrends inc.");
+//println("Main RAM:"+(system.maxmem() >> 10)+" KBytes");
+
+///////////////////////////////////////////////////////////////////////////////
+
+// Perform memtest
+
+let memptr = 0;
+const memtestptn = [
+    [0x00,0xFF,0xAA,0x55 , 0x69,0x0F,0xA5,0x1E , 0xC7,0x71,0x8E,0xE3 , 0xCA,0xFE,0xBA,0xBE],
+    [0xFF,0xFF,0xFF,0xFF , 0xFF,0xFF,0xFF,0xFF , 0xFF,0xFF,0xFF,0xFF , 0xFF,0xFF,0xFF,0xFF]
+];
+
+con.move(2,1);
+print("000 KB OK")
+
+try {
+    while (memptr < (8 << 20)) {
+        // just print a number
+        con.move(2,1);
+        var memptrtext = ""+((memptr + 1) >> 10);
+        print((memptrtext < 10) ? "00"+memptrtext : (memptrtext < 100) ? "0"+memptrtext : memptrtext);
+
+        // perform memory test
+        for (var ptn = 0; ptn < memtestptn.length; ptn++) {
+            for (var bi = 0; bi < memtestptn[ptn].length; bi++) {
+                sys.poke(memptr + bi, memtestptn[ptn][bi]);
+                if (memtestptn[ptn][bi] != sys.peek(memptr + bi)) throw "Memory Error";
+            }
+            for (var bi = 0; bi < memtestptn[ptn].length; bi++) {
+                sys.poke(memptr + bi, 255 - memtestptn[ptn][bi]);
+                if (255 - memtestptn[ptn][bi] != sys.peek(memptr + bi)) throw "Memory Error";
+            }
+        }
+
+        memptr += memtestptn[0].length;
+    }
+}
+catch (e) {
+    if (e == "Memory Error") {
+        println(" "+e);
+    }
+    else {
+        println(" KB OK!");
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+// probe bootable device
+
+var _BIOS = {};
+
+// Syntax: [Port, Drive-number]
+// Port #0-3: Serial port 1-4
+//      #4+ : Left for future extension
+// Drive-number always starts at 1
+_BIOS.FIRST_BOOTABLE_PORT = [0,1]; // ah screw it
+
+Object.freeze(_BIOS);
+
+///////////////////////////////////////////////////////////////////////////////
+
+// load a bootsector using 'LOADBOOT'
+let portNumber = 0;
+let driveStatus = 0;
+while (portNumber < 4) {
+    if (com.areYouThere(portNumber)) {
+        com.sendMessage(portNumber, "LOADBOOT");
+        driveStatus = com.getStatusCode(portNumber);
+        if (driveStatus == 0) break;
+    }
+    portNumber += 1;
+}
+if (portNumber < 4) {
+    eval(com.fetchResponse(portNumber).trimNull());
+}
+else {
+    printerrln("No bootable medium found.");
+}