jalr

contracts/MIPS.sol

@@ -25,6 +25,7 @@ contract MIPS {
 
   uint32 constant public REG_OFFSET = 0xc0000000;
   uint32 constant public REG_ZERO = REG_OFFSET;
+  uint32 constant public REG_LR = REG_OFFSET + 0x1f*4;
   uint32 constant public REG_PC = REG_OFFSET + 0x20*4;
   uint32 constant public REG_HI = REG_OFFSET + 0x21*4;
   uint32 constant public REG_LO = REG_OFFSET + 0x22*4;
@@ -113,11 +114,6 @@ contract MIPS {
       }
     }
 
-    if (opcode == 0 && func == 8) {
-      // jr
-      storeAddr = REG_PC;
-    }
-
     bool shouldBranch = false;
 
     uint32 val;
@@ -165,6 +161,24 @@ contract MIPS {
       }
     }
 
+    // jumps
+
+    if (opcode == 0 && func == 8) {
+      // jr (val is already right)
+      storeAddr = REG_PC;
+    }
+    if (opcode == 0 && func == 9) {
+      // jalr
+      stateHash = m.WriteMemory(stateHash, storeAddr, pc+8);
+      storeAddr = REG_PC;
+    }
+
+    if (opcode == 2 || opcode == 3) {
+      if (opcode == 3) stateHash = m.WriteMemory(stateHash, REG_LR, pc+8);
+      val = SE(insn&0x03FFFFFF, 26) << 2;
+      storeAddr = REG_PC;
+    }
+
     if (shouldBranch) {
       val = pc + (SE(insn&0xFFFF, 16)<<2);
       storeAddr = REG_PC;

mipsevm/main.go

@@ -143,6 +143,7 @@ func opStaticCall(pc *uint64, interpreter *vm.EVMInterpreter, scope *vm.ScopeCon
 
 func runTest(fn string, steps int, interpreter *vm.EVMInterpreter, bytecode []byte) {
 	ram = make(map[uint64](uint32))
+	ram[0xC000007C] = 0xDEAD0000
 	//fmt.Println("starting", fn)
 	dat, _ := ioutil.ReadFile(fn)
 	for i := 0; i < len(dat); i += 4 {

mipsevm/maketests.py

@@ -22,7 +22,8 @@ for d in os.listdir("test/"):
     if sec.name == ".test":
       with open("test/bin/"+(d.replace(".asm", ".bin")), "wb") as f:
         # jump to 0xdead0000 when done
-        data = b"\x24\x1f\xde\xad\x00\x1f\xfc\x00" + sec.data()
+        #data = b"\x24\x1f\xde\xad\x00\x1f\xfc\x00" + sec.data()
+        data = sec.data()
         for dd in md.disasm(data, 0):
           print(dd)
         f.write(data)