Fix `TestClaimEVM`

cannon/mipsevm/evm_test.go

@@ -79,7 +79,7 @@ func (m *MIPSEVM) Step(t *testing.T, stepWitness *StepWitness) []byte {
 		t.Logf("reading preimage key %x at offset %d", stepWitness.PreimageKey, stepWitness.PreimageOffset)
 		poInput, err := stepWitness.EncodePreimageOracleInput()
 		require.NoError(t, err, "encode preimage oracle input")
-		_, leftOverGas, err := m.env.Call(vm.AccountRef(m.addrs.Sender), m.addrs.Oracle, poInput, startingGas, big.NewInt(0))
+		_, leftOverGas, err := m.env.Call(vm.AccountRef(sender), m.addrs.Oracle, poInput, startingGas, big.NewInt(0))
 		require.NoErrorf(t, err, "evm should not fail, took %d gas", startingGas-leftOverGas)
 	}
 

cannon/mipsevm/witness.go

@@ -56,11 +56,11 @@ func (wit *StepWitness) EncodePreimageOracleInput() ([]byte, error) {
 		input = append(input, LoadLocalDataBytes4...)
 		input = append(input, wit.PreimageKey[:]...)
 
-		preimagePart := wit.PreimageValue[wit.PreimageOffset:]
+		preimagePart := wit.PreimageValue[8:]
 		var tmp [32]byte
 		copy(tmp[:], preimagePart)
 		input = append(input, tmp[:]...)
-		input = append(input, uint32ToBytes32(32)...)
+		input = append(input, uint32ToBytes32(uint32(len(wit.PreimageValue)-8))...)
 		input = append(input, uint32ToBytes32(wit.PreimageOffset)...)
 		// Note: we can pad calldata to 32 byte multiple, but don't strictly have to
 		return input, nil

packages/contracts-bedrock/src/cannon/MIPS.sol

@@ -20,6 +20,7 @@ import { PreimageKeyLib } from "./PreimageKeyLib.sol";
 /// @dev https://github.com/golang/go/blob/master/src/syscall/zerrors_linux_mips.go
 ///      MIPS linux kernel errors used by Go runtime
 contract MIPS {
+
     /// @notice Stores the VM state.
     ///         Total state size: 32 + 32 + 6 * 4 + 1 + 1 + 8 + 32 * 4 = 226 bytes
     ///         If nextPC != pc + 4, then the VM is executing a branch/jump delay slot.
@@ -836,11 +837,11 @@ contract MIPS {
                     }
                     // slt: Set to 1 if less than
                     else if (func == 0x2a) {
-                      return int32(rs) < int32(rt) ? 1 : 0;
+                        return int32(rs) < int32(rt) ? 1 : 0;
                     }
                     // sltu: Set to 1 if less than unsigned
                     else if (func == 0x2B) {
-                      return rs<rt ? 1 : 0;
+                        return rs<rt ? 1 : 0;
                     }
                 }
                 // lui: Load Upper Immediate