there might be an off by 1 error...

core/broadway.cpp

@@ -17,27 +17,66 @@ void broadway::set_pc(ircolib::u32 value) { pc = value; }
 
 void broadway::run(mem &mem) {
     for (int i = 0; i < 12150000; i++) {
+        // std::println("pc: 0x{:08X}", pc);
         execute(fetch(mem), mem);
     }
 }
 
 ircolib::u32 broadway::fetch(mem &mem) {
-    ircolib::u32 val = mem.read32(pc);
+    ircolib::u32 val = mem.read32(pc)
+                       .and_then([&](ircolib::u32 val) { return std::expected<ircolib::u32, std::string>(val); })
+                       .or_else([&](std::string e) {
+                           ircolib::panic("broadway read failed. Reason {} (pc: 0x{:08X})", e, pc);
+                           return std::expected<ircolib::u32, std::string>();
+                       })
+                       .value();
     pc += 4;
 
     return val;
 }
 
+void broadway::decode_special3(ircolib::u32 instr, mem &mem) {
+    auto secondary = utils::secondary(instr);
+    switch (secondary) {
+    case 38:
+        mtfsb1(instr);
+        break;
+    case 711:
+        mtfsf(instr);
+        break;
+    default:
+        ircolib::panic("broadway unknown special3 {} (0x{:04X}) (pc 0x{:08X})", secondary, secondary, pc - 4);
+    }
+}
+
 void broadway::decode_special2(ircolib::u32 instr, mem &mem) {
     auto secondary = utils::secondary(instr);
     switch (secondary) {
+    case 0x000:
+        cmp(instr);
+        break;
+    case 0x020:
+        cmpl(instr);
+        break;
+    case 0x028:
+        subf(instr);
+        break;
+    case 0x053:
+        mfmsr(instr);
+        break;
     case 0x0D2:
         ircolib::warn("broadway TODO mtsr (pc 0x{:08X})", pc - 4);
         break;
+    case 0x1BC:
+        or (instr);
+        break;
     case 0x153:
     case 0x1D3:
         mftspr(ircolib::is_bit_set<ircolib::u32, 7>(secondary), instr);
         break;
+    case 0x1DC:
+        nand(instr);
+        break;
     case 0x10A:
         add(instr);
         break;
@@ -66,6 +105,9 @@ void broadway::decode_special1(ircolib::u32 instr, mem &mem) {
 
 void broadway::execute(ircolib::u32 instr, mem &mem) {
     switch (utils::primary(instr)) {
+    case 10:
+        cmpli(instr);
+        break;
     case 11:
         cmpi(instr);
         break;
@@ -111,12 +153,18 @@ void broadway::execute(ircolib::u32 instr, mem &mem) {
     case 37:
         stwu(instr, mem);
         break;
+    case 39:
+        stbu(instr, mem);
+        break;
     case 44:
         sth(instr, mem);
         break;
     case 50:
         lfd(instr, mem);
         break;
+    case 63:
+        decode_special3(instr, mem);
+        break;
     default:
         std::println("broadway::execute unimplemented instruction 0x{:08X} / 0b{:032b}", instr, instr);
         std::println("disassembly:");