Refactored state, state object and vm

* The State and StateObject have been moved to their own package
* The VM is moved to it's own package

15 files changed, 2242 insertions, 1 deletions

diff --git a/ethchain/state_manager.go b/ethchain/state_manager.go
index 6a6c67492..8dc88d7c3 100644
--- a/ethchain/state_manager.go
+++ b/ethchain/state_manager.go
@@ -123,9 +123,9 @@ done:
 
 		cb := state.GetStateObject(coinbase.Address())
 		st := NewStateTransition(cb, tx, state, block)
-		//fmt.Printf("#%d\n", i+1)
 		err = st.TransitionState()
 		if err != nil {
+			statelogger.Infoln(err)
 			switch {
 			case IsNonceErr(err):
 				err = nil // ignore error
diff --git a/ethpub/pub.go b/ethpub/pub.go
index 5d01a7a44..2650edf02 100644
--- a/ethpub/pub.go
+++ b/ethpub/pub.go
@@ -48,6 +48,12 @@ type PEthereum struct {
 }
 
 func NewPEthereum(manager ethchain.EthManager) *PEthereum {
+	logger.Warnln("DEPRECATED: ethpub.New should be used in favour of ethpub.NewPEthereum")
+
+	return New(manager)
+}
+
+func New(manager ethchain.EthManager) *PEthereum {
 	return &PEthereum{
 		manager,
 		manager.StateManager(),
diff --git a/ethstate/.ethtest b/ethstate/.ethtest
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/ethstate/.ethtest
diff --git a/ethstate/errors.go b/ethstate/errors.go
new file mode 100644
index 000000000..d5d7db86b
--- /dev/null
+++ b/ethstate/errors.go
@@ -0,0 +1,23 @@
+package ethstate
+
+import (
+	"fmt"
+	"math/big"
+)
+
+type GasLimitErr struct {
+	Message string
+	Is, Max *big.Int
+}
+
+func IsGasLimitErr(err error) bool {
+	_, ok := err.(*GasLimitErr)
+
+	return ok
+}
+func (err *GasLimitErr) Error() string {
+	return err.Message
+}
+func GasLimitError(is, max *big.Int) *GasLimitErr {
+	return &GasLimitErr{Message: fmt.Sprintf("GasLimit error. Max %s, transaction would take it to %s", max, is), Is: is, Max: max}
+}
diff --git a/ethstate/state.go b/ethstate/state.go
new file mode 100644
index 000000000..a4b9b1e9c
--- /dev/null
+++ b/ethstate/state.go
@@ -0,0 +1,259 @@
+package ethstate
+
+import (
+	"github.com/ethereum/eth-go/ethcrypto"
+	"github.com/ethereum/eth-go/ethlog"
+	"github.com/ethereum/eth-go/ethtrie"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+var statelogger = ethlog.NewLogger("STATE")
+
+// States within the ethereum protocol are used to store anything
+// within the merkle trie. States take care of caching and storing
+// nested states. It's the general query interface to retrieve:
+// * Contracts
+// * Accounts
+type State struct {
+	// The trie for this structure
+	trie *ethtrie.Trie
+
+	stateObjects map[string]*StateObject
+
+	manifest *Manifest
+}
+
+// Create a new state from a given trie
+func NewState(trie *ethtrie.Trie) *State {
+	return &State{trie: trie, stateObjects: make(map[string]*StateObject), manifest: NewManifest()}
+}
+
+// Retrieve the balance from the given address or 0 if object not found
+func (self *State) GetBalance(addr []byte) *big.Int {
+	stateObject := self.GetStateObject(addr)
+	if stateObject != nil {
+		return stateObject.Amount
+	}
+
+	return ethutil.Big0
+}
+
+func (self *State) GetNonce(addr []byte) uint64 {
+	stateObject := self.GetStateObject(addr)
+	if stateObject != nil {
+		return stateObject.Nonce
+	}
+
+	return 0
+}
+
+//
+// Setting, updating & deleting state object methods
+//
+
+// Update the given state object and apply it to state trie
+func (self *State) UpdateStateObject(stateObject *StateObject) {
+	addr := stateObject.Address()
+
+	ethutil.Config.Db.Put(ethcrypto.Sha3Bin(stateObject.Code), stateObject.Code)
+
+	self.trie.Update(string(addr), string(stateObject.RlpEncode()))
+
+	self.manifest.AddObjectChange(stateObject)
+}
+
+// Delete the given state object and delete it from the state trie
+func (self *State) DeleteStateObject(stateObject *StateObject) {
+	self.trie.Delete(string(stateObject.Address()))
+
+	delete(self.stateObjects, string(stateObject.Address()))
+}
+
+// Retrieve a state object given my the address. Nil if not found
+func (self *State) GetStateObject(addr []byte) *StateObject {
+	addr = ethutil.Address(addr)
+
+	stateObject := self.stateObjects[string(addr)]
+	if stateObject != nil {
+		return stateObject
+	}
+
+	data := self.trie.Get(string(addr))
+	if len(data) == 0 {
+		return nil
+	}
+
+	stateObject = NewStateObjectFromBytes(addr, []byte(data))
+	self.stateObjects[string(addr)] = stateObject
+
+	return stateObject
+}
+
+// Retrieve a state object or create a new state object if nil
+func (self *State) GetOrNewStateObject(addr []byte) *StateObject {
+	stateObject := self.GetStateObject(addr)
+	if stateObject == nil {
+		stateObject = self.NewStateObject(addr)
+	}
+
+	return stateObject
+}
+
+// Create a state object whether it exist in the trie or not
+func (self *State) NewStateObject(addr []byte) *StateObject {
+	addr = ethutil.Address(addr)
+
+	statelogger.Infof("(+) %x\n", addr)
+
+	stateObject := NewStateObject(addr)
+	self.stateObjects[string(addr)] = stateObject
+
+	return stateObject
+}
+
+// Deprecated
+func (self *State) GetAccount(addr []byte) *StateObject {
+	return self.GetOrNewStateObject(addr)
+}
+
+//
+// Setting, copying of the state methods
+//
+
+func (s *State) Cmp(other *State) bool {
+	return s.trie.Cmp(other.trie)
+}
+
+func (self *State) Copy() *State {
+	if self.trie != nil {
+		state := NewState(self.trie.Copy())
+		for k, stateObject := range self.stateObjects {
+			state.stateObjects[k] = stateObject.Copy()
+		}
+
+		return state
+	}
+
+	return nil
+}
+
+func (self *State) Set(state *State) {
+	if state == nil {
+		panic("Tried setting 'state' to nil through 'Set'")
+	}
+
+	self.trie = state.trie
+	self.stateObjects = state.stateObjects
+}
+
+func (s *State) Root() interface{} {
+	return s.trie.Root
+}
+
+// Resets the trie and all siblings
+func (s *State) Reset() {
+	s.trie.Undo()
+
+	// Reset all nested states
+	for _, stateObject := range s.stateObjects {
+		if stateObject.state == nil {
+			continue
+		}
+
+		//stateObject.state.Reset()
+		stateObject.Reset()
+	}
+
+	s.Empty()
+}
+
+// Syncs the trie and all siblings
+func (s *State) Sync() {
+	// Sync all nested states
+	for _, stateObject := range s.stateObjects {
+		//s.UpdateStateObject(stateObject)
+
+		if stateObject.state == nil {
+			continue
+		}
+
+		stateObject.state.Sync()
+	}
+
+	s.trie.Sync()
+
+	s.Empty()
+}
+
+func (self *State) Empty() {
+	self.stateObjects = make(map[string]*StateObject)
+}
+
+func (self *State) Update() {
+	for _, stateObject := range self.stateObjects {
+		if stateObject.remove {
+			self.DeleteStateObject(stateObject)
+		} else {
+			stateObject.Sync()
+
+			self.UpdateStateObject(stateObject)
+		}
+	}
+
+	// FIXME trie delete is broken
+	valid, t2 := ethtrie.ParanoiaCheck(self.trie)
+	if !valid {
+		statelogger.Infof("Warn: PARANOIA: Different state root during copy %x vs %x\n", self.trie.Root, t2.Root)
+
+		self.trie = t2
+	}
+}
+
+// Debug stuff
+func (self *State) CreateOutputForDiff() {
+	for _, stateObject := range self.stateObjects {
+		stateObject.CreateOutputForDiff()
+	}
+}
+
+func (self *State) Manifest() *Manifest {
+	return self.manifest
+}
+
+// Object manifest
+//
+// The object manifest is used to keep changes to the state so we can keep track of the changes
+// that occurred during a state transitioning phase.
+type Manifest struct {
+	// XXX These will be handy in the future. Not important for now.
+	objectAddresses  map[string]bool
+	storageAddresses map[string]map[string]bool
+
+	objectChanges  map[string]*StateObject
+	storageChanges map[string]map[string]*big.Int
+}
+
+func NewManifest() *Manifest {
+	m := &Manifest{objectAddresses: make(map[string]bool), storageAddresses: make(map[string]map[string]bool)}
+	m.Reset()
+
+	return m
+}
+
+func (m *Manifest) Reset() {
+	m.objectChanges = make(map[string]*StateObject)
+	m.storageChanges = make(map[string]map[string]*big.Int)
+}
+
+func (m *Manifest) AddObjectChange(stateObject *StateObject) {
+	m.objectChanges[string(stateObject.Address())] = stateObject
+}
+
+func (m *Manifest) AddStorageChange(stateObject *StateObject, storageAddr []byte, storage *big.Int) {
+	if m.storageChanges[string(stateObject.Address())] == nil {
+		m.storageChanges[string(stateObject.Address())] = make(map[string]*big.Int)
+	}
+
+	m.storageChanges[string(stateObject.Address())][string(storageAddr)] = storage
+}
diff --git a/ethstate/state_object.go b/ethstate/state_object.go
new file mode 100644
index 000000000..d8513f37d
--- /dev/null
+++ b/ethstate/state_object.go
@@ -0,0 +1,339 @@
+package ethstate
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethcrypto"
+	"github.com/ethereum/eth-go/ethtrie"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+type Code []byte
+
+func (self Code) String() string {
+	return "" //strings.Join(Disassemble(self), " ")
+}
+
+type Storage map[string]*ethutil.Value
+
+func (self Storage) Copy() Storage {
+	cpy := make(Storage)
+	for key, value := range self {
+		// XXX Do we need a 'value' copy or is this sufficient?
+		cpy[key] = value
+	}
+
+	return cpy
+}
+
+type StateObject struct {
+	// Address of the object
+	address []byte
+	// Shared attributes
+	Amount   *big.Int
+	CodeHash []byte
+	Nonce    uint64
+	// Contract related attributes
+	state    *State
+	Code     Code
+	initCode Code
+
+	storage Storage
+
+	// Total gas pool is the total amount of gas currently
+	// left if this object is the coinbase. Gas is directly
+	// purchased of the coinbase.
+	gasPool *big.Int
+
+	// Mark for deletion
+	// When an object is marked for deletion it will be delete from the trie
+	// during the "update" phase of the state transition
+	remove bool
+}
+
+func (self *StateObject) Reset() {
+	self.storage = make(Storage)
+	self.state.Reset()
+}
+
+/*
+// Converts an transaction in to a state object
+func MakeContract(tx *Transaction, state *State) *StateObject {
+	// Create contract if there's no recipient
+	if tx.IsContract() {
+		addr := tx.CreationAddress()
+
+		contract := state.NewStateObject(addr)
+		contract.initCode = tx.Data
+		contract.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, ""))
+
+		return contract
+	}
+
+	return nil
+}
+*/
+
+func NewStateObject(addr []byte) *StateObject {
+	// This to ensure that it has 20 bytes (and not 0 bytes), thus left or right pad doesn't matter.
+	address := ethutil.Address(addr)
+
+	object := &StateObject{address: address, Amount: new(big.Int), gasPool: new(big.Int)}
+	object.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, ""))
+	object.storage = make(Storage)
+	object.gasPool = new(big.Int)
+
+	return object
+}
+
+func NewContract(address []byte, Amount *big.Int, root []byte) *StateObject {
+	contract := NewStateObject(address)
+	contract.Amount = Amount
+	contract.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, string(root)))
+
+	return contract
+}
+
+func NewStateObjectFromBytes(address, data []byte) *StateObject {
+	object := &StateObject{address: address}
+	object.RlpDecode(data)
+
+	return object
+}
+
+func (self *StateObject) MarkForDeletion() {
+	self.remove = true
+	statelogger.DebugDetailf("%x: #%d %v (deletion)\n", self.Address(), self.Nonce, self.Amount)
+}
+
+func (c *StateObject) GetAddr(addr []byte) *ethutil.Value {
+	return ethutil.NewValueFromBytes([]byte(c.state.trie.Get(string(addr))))
+}
+
+func (c *StateObject) SetAddr(addr []byte, value interface{}) {
+	c.state.trie.Update(string(addr), string(ethutil.NewValue(value).Encode()))
+}
+
+func (self *StateObject) GetStorage(key *big.Int) *ethutil.Value {
+	return self.getStorage(key.Bytes())
+}
+func (self *StateObject) SetStorage(key *big.Int, value *ethutil.Value) {
+	self.setStorage(key.Bytes(), value)
+}
+
+func (self *StateObject) getStorage(k []byte) *ethutil.Value {
+	key := ethutil.LeftPadBytes(k, 32)
+
+	value := self.storage[string(key)]
+	if value == nil {
+		value = self.GetAddr(key)
+
+		if !value.IsNil() {
+			self.storage[string(key)] = value
+		}
+	}
+
+	return value
+
+	//return self.GetAddr(key)
+}
+
+func (self *StateObject) setStorage(k []byte, value *ethutil.Value) {
+	key := ethutil.LeftPadBytes(k, 32)
+	self.storage[string(key)] = value.Copy()
+}
+
+// Iterate over each storage address and yield callback
+func (self *StateObject) EachStorage(cb ethtrie.EachCallback) {
+	// First loop over the uncommit/cached values in storage
+	for key, value := range self.storage {
+		// XXX Most iterators Fns as it stands require encoded values
+		encoded := ethutil.NewValue(value.Encode())
+		cb(key, encoded)
+	}
+
+	it := self.state.trie.NewIterator()
+	it.Each(func(key string, value *ethutil.Value) {
+		// If it's cached don't call the callback.
+		if self.storage[key] == nil {
+			cb(key, value)
+		}
+	})
+}
+
+func (self *StateObject) Sync() {
+	for key, value := range self.storage {
+		if value.Len() == 0 { // value.BigInt().Cmp(ethutil.Big0) == 0 {
+			//data := self.getStorage([]byte(key))
+			//fmt.Printf("deleting %x %x 0x%x\n", self.Address(), []byte(key), data)
+			self.state.trie.Delete(string(key))
+			continue
+		}
+
+		self.SetAddr([]byte(key), value)
+	}
+
+	valid, t2 := ethtrie.ParanoiaCheck(self.state.trie)
+	if !valid {
+		statelogger.Infof("Warn: PARANOIA: Different state storage root during copy %x vs %x\n", self.state.trie.Root, t2.Root)
+
+		self.state.trie = t2
+	}
+}
+
+func (c *StateObject) GetInstr(pc *big.Int) *ethutil.Value {
+	if int64(len(c.Code)-1) < pc.Int64() {
+		return ethutil.NewValue(0)
+	}
+
+	return ethutil.NewValueFromBytes([]byte{c.Code[pc.Int64()]})
+}
+
+func (c *StateObject) AddAmount(amount *big.Int) {
+	c.SetAmount(new(big.Int).Add(c.Amount, amount))
+
+	statelogger.Debugf("%x: #%d %v (+ %v)\n", c.Address(), c.Nonce, c.Amount, amount)
+}
+
+func (c *StateObject) SubAmount(amount *big.Int) {
+	c.SetAmount(new(big.Int).Sub(c.Amount, amount))
+
+	statelogger.Debugf("%x: #%d %v (- %v)\n", c.Address(), c.Nonce, c.Amount, amount)
+}
+
+func (c *StateObject) SetAmount(amount *big.Int) {
+	c.Amount = amount
+}
+
+//
+// Gas setters and getters
+//
+
+// Return the gas back to the origin. Used by the Virtual machine or Closures
+func (c *StateObject) ReturnGas(gas, price *big.Int) {}
+func (c *StateObject) ConvertGas(gas, price *big.Int) error {
+	total := new(big.Int).Mul(gas, price)
+	if total.Cmp(c.Amount) > 0 {
+		return fmt.Errorf("insufficient amount: %v, %v", c.Amount, total)
+	}
+
+	c.SubAmount(total)
+
+	return nil
+}
+
+func (self *StateObject) SetGasPool(gasLimit *big.Int) {
+	self.gasPool = new(big.Int).Set(gasLimit)
+
+	statelogger.DebugDetailf("%x: fuel (+ %v)", self.Address(), self.gasPool)
+}
+
+func (self *StateObject) BuyGas(gas, price *big.Int) error {
+	if self.gasPool.Cmp(gas) < 0 {
+		return GasLimitError(self.gasPool, gas)
+	}
+
+	rGas := new(big.Int).Set(gas)
+	rGas.Mul(rGas, price)
+
+	self.AddAmount(rGas)
+
+	return nil
+}
+
+func (self *StateObject) RefundGas(gas, price *big.Int) {
+	self.gasPool.Add(self.gasPool, gas)
+
+	rGas := new(big.Int).Set(gas)
+	rGas.Mul(rGas, price)
+
+	self.Amount.Sub(self.Amount, rGas)
+}
+
+func (self *StateObject) Copy() *StateObject {
+	stateObject := NewStateObject(self.Address())
+	stateObject.Amount.Set(self.Amount)
+	stateObject.CodeHash = ethutil.CopyBytes(self.CodeHash)
+	stateObject.Nonce = self.Nonce
+	if self.state != nil {
+		stateObject.state = self.state.Copy()
+	}
+	stateObject.Code = ethutil.CopyBytes(self.Code)
+	stateObject.initCode = ethutil.CopyBytes(self.initCode)
+	stateObject.storage = self.storage.Copy()
+	stateObject.gasPool.Set(self.gasPool)
+
+	return stateObject
+}
+
+func (self *StateObject) Set(stateObject *StateObject) {
+	*self = *stateObject
+}
+
+//
+// Attribute accessors
+//
+
+func (c *StateObject) State() *State {
+	return c.state
+}
+
+func (c *StateObject) N() *big.Int {
+	return big.NewInt(int64(c.Nonce))
+}
+
+// Returns the address of the contract/account
+func (c *StateObject) Address() []byte {
+	return c.address
+}
+
+// Returns the initialization Code
+func (c *StateObject) Init() Code {
+	return c.initCode
+}
+
+// Debug stuff
+func (self *StateObject) CreateOutputForDiff() {
+	fmt.Printf("%x %x %x %x\n", self.Address(), self.state.Root(), self.Amount.Bytes(), self.Nonce)
+	self.EachStorage(func(addr string, value *ethutil.Value) {
+		fmt.Printf("%x %x\n", addr, value.Bytes())
+	})
+}
+
+//
+// Encoding
+//
+
+// State object encoding methods
+func (c *StateObject) RlpEncode() []byte {
+	var root interface{}
+	if c.state != nil {
+		root = c.state.trie.Root
+	} else {
+		root = ""
+	}
+
+	return ethutil.Encode([]interface{}{c.Nonce, c.Amount, root, ethcrypto.Sha3Bin(c.Code)})
+}
+
+func (c *StateObject) RlpDecode(data []byte) {
+	decoder := ethutil.NewValueFromBytes(data)
+
+	c.Nonce = decoder.Get(0).Uint()
+	c.Amount = decoder.Get(1).BigInt()
+	c.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, decoder.Get(2).Interface()))
+	c.storage = make(map[string]*ethutil.Value)
+	c.gasPool = new(big.Int)
+
+	c.CodeHash = decoder.Get(3).Bytes()
+
+	c.Code, _ = ethutil.Config.Db.Get(c.CodeHash)
+}
+
+// Storage change object. Used by the manifest for notifying changes to
+// the sub channels.
+type StorageState struct {
+	StateAddress []byte
+	Address      []byte
+	Value        *big.Int
+}
diff --git a/ethstate/state_test.go b/ethstate/state_test.go
new file mode 100644
index 000000000..cd13e80bc
--- /dev/null
+++ b/ethstate/state_test.go
@@ -0,0 +1,35 @@
+package ethstate
+
+import (
+	"github.com/ethereum/eth-go/ethdb"
+	"github.com/ethereum/eth-go/ethtrie"
+	"github.com/ethereum/eth-go/ethutil"
+	"testing"
+)
+
+var ZeroHash256 = make([]byte, 32)
+
+func TestSnapshot(t *testing.T) {
+	db, _ := ethdb.NewMemDatabase()
+	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
+	ethutil.Config.Db = db
+
+	state := NewState(ethtrie.NewTrie(db, ""))
+
+	stateObject := state.GetOrNewStateObject([]byte("aa"))
+
+	stateObject.SetStorage(ethutil.Big("0"), ethutil.NewValue(42))
+
+	snapshot := state.Copy()
+
+	stateObject = state.GetStateObject([]byte("aa"))
+	stateObject.SetStorage(ethutil.Big("0"), ethutil.NewValue(43))
+
+	state.Set(snapshot)
+
+	stateObject = state.GetStateObject([]byte("aa"))
+	res := stateObject.GetStorage(ethutil.Big("0"))
+	if !res.Cmp(ethutil.NewValue(42)) {
+		t.Error("Expected storage 0 to be 42", res)
+	}
+}
diff --git a/ethvm/.ethtest b/ethvm/.ethtest
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/ethvm/.ethtest
diff --git a/ethvm/asm.go b/ethvm/asm.go
new file mode 100644
index 000000000..fd559d1dc
--- /dev/null
+++ b/ethvm/asm.go
@@ -0,0 +1,44 @@
+package ethvm
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+func Disassemble(script []byte) (asm []string) {
+	pc := new(big.Int)
+	for {
+		if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 {
+			return
+		}
+
+		// Get the memory location of pc
+		val := script[pc.Int64()]
+		// Get the opcode (it must be an opcode!)
+		op := OpCode(val)
+
+		asm = append(asm, fmt.Sprintf("%04v: %v", pc, op))
+
+		switch op {
+		case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
+			pc.Add(pc, ethutil.Big1)
+			a := int64(op) - int64(PUSH1) + 1
+			if int(pc.Int64()+a) > len(script) {
+				return nil
+			}
+
+			data := script[pc.Int64() : pc.Int64()+a]
+			if len(data) == 0 {
+				data = []byte{0}
+			}
+			asm = append(asm, fmt.Sprintf("%04v: 0x%x", pc, data))
+
+			pc.Add(pc, big.NewInt(a-1))
+		}
+
+		pc.Add(pc, ethutil.Big1)
+	}
+
+	return
+}
diff --git a/ethvm/closure.go b/ethvm/closure.go
new file mode 100644
index 000000000..505fd43fb
--- /dev/null
+++ b/ethvm/closure.go
@@ -0,0 +1,116 @@
+package ethvm
+
+// TODO Re write VM to use values instead of big integers?
+
+import (
+	"github.com/ethereum/eth-go/ethstate"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+type ClosureRef interface {
+	ReturnGas(*big.Int, *big.Int)
+	Address() []byte
+	GetStorage(*big.Int) *ethutil.Value
+	SetStorage(*big.Int, *ethutil.Value)
+}
+
+// Basic inline closure object which implement the 'closure' interface
+type Closure struct {
+	caller ClosureRef
+	object *ethstate.StateObject
+	Code   []byte
+
+	Gas, UsedGas, Price *big.Int
+
+	Args []byte
+}
+
+// Create a new closure for the given data items
+func NewClosure(caller ClosureRef, object *ethstate.StateObject, code []byte, gas, price *big.Int) *Closure {
+	c := &Closure{caller: caller, object: object, Code: code, Args: nil}
+
+	// Gas should be a pointer so it can safely be reduced through the run
+	// This pointer will be off the state transition
+	c.Gas = gas //new(big.Int).Set(gas)
+	// In most cases price and value are pointers to transaction objects
+	// and we don't want the transaction's values to change.
+	c.Price = new(big.Int).Set(price)
+	c.UsedGas = new(big.Int)
+
+	return c
+}
+
+// Retuns the x element in data slice
+func (c *Closure) GetStorage(x *big.Int) *ethutil.Value {
+	m := c.object.GetStorage(x)
+	if m == nil {
+		return ethutil.EmptyValue()
+	}
+
+	return m
+}
+
+func (c *Closure) Get(x *big.Int) *ethutil.Value {
+	return c.Gets(x, big.NewInt(1))
+}
+
+func (c *Closure) Gets(x, y *big.Int) *ethutil.Value {
+	if x.Int64() >= int64(len(c.Code)) || y.Int64() >= int64(len(c.Code)) {
+		return ethutil.NewValue(0)
+	}
+
+	partial := c.Code[x.Int64() : x.Int64()+y.Int64()]
+
+	return ethutil.NewValue(partial)
+}
+
+func (c *Closure) SetStorage(x *big.Int, val *ethutil.Value) {
+	c.object.SetStorage(x, val)
+}
+
+func (c *Closure) Address() []byte {
+	return c.object.Address()
+}
+
+func (c *Closure) Call(vm *Vm, args []byte) ([]byte, *big.Int, error) {
+	c.Args = args
+
+	ret, err := vm.RunClosure(c)
+
+	return ret, c.UsedGas, err
+}
+
+func (c *Closure) Return(ret []byte) []byte {
+	// Return the remaining gas to the caller
+	c.caller.ReturnGas(c.Gas, c.Price)
+
+	return ret
+}
+
+func (c *Closure) UseGas(gas *big.Int) bool {
+	if c.Gas.Cmp(gas) < 0 {
+		return false
+	}
+
+	// Sub the amount of gas from the remaining
+	c.Gas.Sub(c.Gas, gas)
+	c.UsedGas.Add(c.UsedGas, gas)
+
+	return true
+}
+
+// Implement the caller interface
+func (c *Closure) ReturnGas(gas, price *big.Int) {
+	// Return the gas to the closure
+	c.Gas.Add(c.Gas, gas)
+	c.UsedGas.Sub(c.UsedGas, gas)
+}
+
+func (c *Closure) Object() *ethstate.StateObject {
+	return c.object
+}
+
+func (c *Closure) Caller() ClosureRef {
+	return c.caller
+}
diff --git a/ethvm/common.go b/ethvm/common.go
new file mode 100644
index 000000000..5a3aec648
--- /dev/null
+++ b/ethvm/common.go
@@ -0,0 +1,27 @@
+package ethvm
+
+import (
+	"github.com/ethereum/eth-go/ethlog"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+var vmlogger = ethlog.NewLogger("VM")
+
+var (
+	GasStep    = big.NewInt(1)
+	GasSha     = big.NewInt(20)
+	GasSLoad   = big.NewInt(20)
+	GasSStore  = big.NewInt(100)
+	GasBalance = big.NewInt(20)
+	GasCreate  = big.NewInt(100)
+	GasCall    = big.NewInt(20)
+	GasMemory  = big.NewInt(1)
+	GasData    = big.NewInt(5)
+	GasTx      = big.NewInt(500)
+
+	Pow256 = ethutil.BigPow(2, 256)
+
+	LogTyPretty byte = 0x1
+	LogTyDiff   byte = 0x2
+)
diff --git a/ethvm/stack.go b/ethvm/stack.go
new file mode 100644
index 000000000..c06d63652
--- /dev/null
+++ b/ethvm/stack.go
@@ -0,0 +1,150 @@
+package ethvm
+
+import (
+	"fmt"
+	"math"
+	"math/big"
+)
+
+type OpType int
+
+const (
+	tNorm = iota
+	tData
+	tExtro
+	tCrypto
+)
+
+type TxCallback func(opType OpType) bool
+
+// Simple push/pop stack mechanism
+type Stack struct {
+	data []*big.Int
+}
+
+func NewStack() *Stack {
+	return &Stack{}
+}
+
+func (st *Stack) Data() []*big.Int {
+	return st.data
+}
+
+func (st *Stack) Len() int {
+	return len(st.data)
+}
+
+func (st *Stack) Pop() *big.Int {
+	str := st.data[len(st.data)-1]
+
+	copy(st.data[:len(st.data)-1], st.data[:len(st.data)-1])
+	st.data = st.data[:len(st.data)-1]
+
+	return str
+}
+
+func (st *Stack) Popn() (*big.Int, *big.Int) {
+	ints := st.data[len(st.data)-2:]
+
+	copy(st.data[:len(st.data)-2], st.data[:len(st.data)-2])
+	st.data = st.data[:len(st.data)-2]
+
+	return ints[0], ints[1]
+}
+
+func (st *Stack) Peek() *big.Int {
+	str := st.data[len(st.data)-1]
+
+	return str
+}
+
+func (st *Stack) Peekn() (*big.Int, *big.Int) {
+	ints := st.data[:2]
+
+	return ints[0], ints[1]
+}
+
+func (st *Stack) Push(d *big.Int) {
+	st.data = append(st.data, new(big.Int).Set(d))
+}
+
+func (st *Stack) Get(amount *big.Int) []*big.Int {
+	// offset + size <= len(data)
+	length := big.NewInt(int64(len(st.data)))
+	if amount.Cmp(length) <= 0 {
+		start := new(big.Int).Sub(length, amount)
+		return st.data[start.Int64():length.Int64()]
+	}
+
+	return nil
+}
+
+func (st *Stack) Print() {
+	fmt.Println("### stack ###")
+	if len(st.data) > 0 {
+		for i, val := range st.data {
+			fmt.Printf("%-3d  %v\n", i, val)
+		}
+	} else {
+		fmt.Println("-- empty --")
+	}
+	fmt.Println("#############")
+}
+
+type Memory struct {
+	store []byte
+}
+
+func (m *Memory) Set(offset, size int64, value []byte) {
+	totSize := offset + size
+	lenSize := int64(len(m.store) - 1)
+	if totSize > lenSize {
+		// Calculate the diff between the sizes
+		diff := totSize - lenSize
+		if diff > 0 {
+			// Create a new empty slice and append it
+			newSlice := make([]byte, diff-1)
+			// Resize slice
+			m.store = append(m.store, newSlice...)
+		}
+	}
+	copy(m.store[offset:offset+size], value)
+}
+
+func (m *Memory) Resize(size uint64) {
+	if uint64(m.Len()) < size {
+		m.store = append(m.store, make([]byte, size-uint64(m.Len()))...)
+	}
+}
+
+func (m *Memory) Get(offset, size int64) []byte {
+	if len(m.store) > int(offset) {
+		end := int(math.Min(float64(len(m.store)), float64(offset+size)))
+
+		return m.store[offset:end]
+	}
+
+	return nil
+}
+
+func (m *Memory) Len() int {
+	return len(m.store)
+}
+
+func (m *Memory) Data() []byte {
+	return m.store
+}
+
+func (m *Memory) Print() {
+	fmt.Printf("### mem %d bytes ###\n", len(m.store))
+	if len(m.store) > 0 {
+		addr := 0
+		for i := 0; i+32 <= len(m.store); i += 32 {
+			fmt.Printf("%03d: % x\n", addr, m.store[i:i+32])
+			addr++
+		}
+	} else {
+		fmt.Println("-- empty --")
+	}
+	fmt.Println("####################")
+}
diff --git a/ethvm/types.go b/ethvm/types.go
new file mode 100644
index 000000000..1c3f66139
--- /dev/null
+++ b/ethvm/types.go
@@ -0,0 +1,346 @@
+package ethvm
+
+import (
+	"fmt"
+)
+
+type OpCode int
+
+// Op codes
+const (
+	// 0x0 range - arithmetic ops
+	STOP = 0x00
+	ADD  = 0x01
+	MUL  = 0x02
+	SUB  = 0x03
+	DIV  = 0x04
+	SDIV = 0x05
+	MOD  = 0x06
+	SMOD = 0x07
+	EXP  = 0x08
+	NEG  = 0x09
+	LT   = 0x0a
+	GT   = 0x0b
+	SLT  = 0x0c
+	SGT  = 0x0d
+	EQ   = 0x0e
+	NOT  = 0x0f
+
+	// 0x10 range - bit ops
+	AND  = 0x10
+	OR   = 0x11
+	XOR  = 0x12
+	BYTE = 0x13
+
+	// 0x20 range - crypto
+	SHA3 = 0x20
+
+	// 0x30 range - closure state
+	ADDRESS      = 0x30
+	BALANCE      = 0x31
+	ORIGIN       = 0x32
+	CALLER       = 0x33
+	CALLVALUE    = 0x34
+	CALLDATALOAD = 0x35
+	CALLDATASIZE = 0x36
+	CALLDATACOPY = 0x37
+	CODESIZE     = 0x38
+	CODECOPY     = 0x39
+	GASPRICE     = 0x3a
+
+	// 0x40 range - block operations
+	PREVHASH   = 0x40
+	COINBASE   = 0x41
+	TIMESTAMP  = 0x42
+	NUMBER     = 0x43
+	DIFFICULTY = 0x44
+	GASLIMIT   = 0x45
+
+	// 0x50 range - 'storage' and execution
+	POP     = 0x50
+	DUP     = 0x51
+	SWAP    = 0x52
+	MLOAD   = 0x53
+	MSTORE  = 0x54
+	MSTORE8 = 0x55
+	SLOAD   = 0x56
+	SSTORE  = 0x57
+	JUMP    = 0x58
+	JUMPI   = 0x59
+	PC      = 0x5a
+	MSIZE   = 0x5b
+	GAS     = 0x5c
+
+	// 0x60 range
+	PUSH1  = 0x60
+	PUSH2  = 0x61
+	PUSH3  = 0x62
+	PUSH4  = 0x63
+	PUSH5  = 0x64
+	PUSH6  = 0x65
+	PUSH7  = 0x66
+	PUSH8  = 0x67
+	PUSH9  = 0x68
+	PUSH10 = 0x69
+	PUSH11 = 0x6a
+	PUSH12 = 0x6b
+	PUSH13 = 0x6c
+	PUSH14 = 0x6d
+	PUSH15 = 0x6e
+	PUSH16 = 0x6f
+	PUSH17 = 0x70
+	PUSH18 = 0x71
+	PUSH19 = 0x72
+	PUSH20 = 0x73
+	PUSH21 = 0x74
+	PUSH22 = 0x75
+	PUSH23 = 0x76
+	PUSH24 = 0x77
+	PUSH25 = 0x78
+	PUSH26 = 0x79
+	PUSH27 = 0x7a
+	PUSH28 = 0x7b
+	PUSH29 = 0x7c
+	PUSH30 = 0x7d
+	PUSH31 = 0x7e
+	PUSH32 = 0x7f
+
+	// 0xf0 range - closures
+	CREATE = 0xf0
+	CALL   = 0xf1
+	RETURN = 0xf2
+
+	// 0x70 range - other
+	LOG     = 0xfe // XXX Unofficial
+	SUICIDE = 0xff
+)
+
+// Since the opcodes aren't all in order we can't use a regular slice
+var opCodeToString = map[OpCode]string{
+	// 0x0 range - arithmetic ops
+	STOP: "STOP",
+	ADD:  "ADD",
+	MUL:  "MUL",
+	SUB:  "SUB",
+	DIV:  "DIV",
+	SDIV: "SDIV",
+	MOD:  "MOD",
+	SMOD: "SMOD",
+	EXP:  "EXP",
+	NEG:  "NEG",
+	LT:   "LT",
+	GT:   "GT",
+	SLT:  "SLT",
+	SGT:  "SGT",
+	EQ:   "EQ",
+	NOT:  "NOT",
+
+	// 0x10 range - bit ops
+	AND:  "AND",
+	OR:   "OR",
+	XOR:  "XOR",
+	BYTE: "BYTE",
+
+	// 0x20 range - crypto
+	SHA3: "SHA3",
+
+	// 0x30 range - closure state
+	ADDRESS:      "ADDRESS",
+	BALANCE:      "BALANCE",
+	ORIGIN:       "ORIGIN",
+	CALLER:       "CALLER",
+	CALLVALUE:    "CALLVALUE",
+	CALLDATALOAD: "CALLDATALOAD",
+	CALLDATASIZE: "CALLDATASIZE",
+	CALLDATACOPY: "CALLDATACOPY",
+	CODESIZE:     "CODESIZE",
+	CODECOPY:     "CODECOPY",
+	GASPRICE:     "TXGASPRICE",
+
+	// 0x40 range - block operations
+	PREVHASH:   "PREVHASH",
+	COINBASE:   "COINBASE",
+	TIMESTAMP:  "TIMESTAMP",
+	NUMBER:     "NUMBER",
+	DIFFICULTY: "DIFFICULTY",
+	GASLIMIT:   "GASLIMIT",
+
+	// 0x50 range - 'storage' and execution
+	POP:     "POP",
+	DUP:     "DUP",
+	SWAP:    "SWAP",
+	MLOAD:   "MLOAD",
+	MSTORE:  "MSTORE",
+	MSTORE8: "MSTORE8",
+	SLOAD:   "SLOAD",
+	SSTORE:  "SSTORE",
+	JUMP:    "JUMP",
+	JUMPI:   "JUMPI",
+	PC:      "PC",
+	MSIZE:   "MSIZE",
+	GAS:     "GAS",
+
+	// 0x60 range - push
+	PUSH1:  "PUSH1",
+	PUSH2:  "PUSH2",
+	PUSH3:  "PUSH3",
+	PUSH4:  "PUSH4",
+	PUSH5:  "PUSH5",
+	PUSH6:  "PUSH6",
+	PUSH7:  "PUSH7",
+	PUSH8:  "PUSH8",
+	PUSH9:  "PUSH9",
+	PUSH10: "PUSH10",
+	PUSH11: "PUSH11",
+	PUSH12: "PUSH12",
+	PUSH13: "PUSH13",
+	PUSH14: "PUSH14",
+	PUSH15: "PUSH15",
+	PUSH16: "PUSH16",
+	PUSH17: "PUSH17",
+	PUSH18: "PUSH18",
+	PUSH19: "PUSH19",
+	PUSH20: "PUSH20",
+	PUSH21: "PUSH21",
+	PUSH22: "PUSH22",
+	PUSH23: "PUSH23",
+	PUSH24: "PUSH24",
+	PUSH25: "PUSH25",
+	PUSH26: "PUSH26",
+	PUSH27: "PUSH27",
+	PUSH28: "PUSH28",
+	PUSH29: "PUSH29",
+	PUSH30: "PUSH30",
+	PUSH31: "PUSH31",
+	PUSH32: "PUSH32",
+
+	// 0xf0 range
+	CREATE: "CREATE",
+	CALL:   "CALL",
+	RETURN: "RETURN",
+
+	// 0x70 range - other
+	LOG:     "LOG",
+	SUICIDE: "SUICIDE",
+}
+
+func (o OpCode) String() string {
+	str := opCodeToString[o]
+	if len(str) == 0 {
+		return fmt.Sprintf("Missing opcode 0x%x", int(o))
+	}
+
+	return str
+}
+
+// Op codes for assembling
+var OpCodes = map[string]byte{
+	// 0x0 range - arithmetic ops
+	"STOP": 0x00,
+	"ADD":  0x01,
+	"MUL":  0x02,
+	"SUB":  0x03,
+	"DIV":  0x04,
+	"SDIV": 0x05,
+	"MOD":  0x06,
+	"SMOD": 0x07,
+	"EXP":  0x08,
+	"NEG":  0x09,
+	"LT":   0x0a,
+	"GT":   0x0b,
+	"EQ":   0x0c,
+	"NOT":  0x0d,
+
+	// 0x10 range - bit ops
+	"AND":  0x10,
+	"OR":   0x11,
+	"XOR":  0x12,
+	"BYTE": 0x13,
+
+	// 0x20 range - crypto
+	"SHA3": 0x20,
+
+	// 0x30 range - closure state
+	"ADDRESS":      0x30,
+	"BALANCE":      0x31,
+	"ORIGIN":       0x32,
+	"CALLER":       0x33,
+	"CALLVALUE":    0x34,
+	"CALLDATALOAD": 0x35,
+	"CALLDATASIZE": 0x36,
+	"GASPRICE":     0x38,
+
+	// 0x40 range - block operations
+	"PREVHASH":   0x40,
+	"COINBASE":   0x41,
+	"TIMESTAMP":  0x42,
+	"NUMBER":     0x43,
+	"DIFFICULTY": 0x44,
+	"GASLIMIT":   0x45,
+
+	// 0x50 range - 'storage' and execution
+	"POP":     0x51,
+	"DUP":     0x52,
+	"SWAP":    0x53,
+	"MLOAD":   0x54,
+	"MSTORE":  0x55,
+	"MSTORE8": 0x56,
+	"SLOAD":   0x57,
+	"SSTORE":  0x58,
+	"JUMP":    0x59,
+	"JUMPI":   0x5a,
+	"PC":      0x5b,
+	"MSIZE":   0x5c,
+
+	// 0x70 range - 'push'
+	"PUSH1":  0x60,
+	"PUSH2":  0x61,
+	"PUSH3":  0x62,
+	"PUSH4":  0x63,
+	"PUSH5":  0x64,
+	"PUSH6":  0x65,
+	"PUSH7":  0x66,
+	"PUSH8":  0x67,
+	"PUSH9":  0x68,
+	"PUSH10": 0x69,
+	"PUSH11": 0x6a,
+	"PUSH12": 0x6b,
+	"PUSH13": 0x6c,
+	"PUSH14": 0x6d,
+	"PUSH15": 0x6e,
+	"PUSH16": 0x6f,
+	"PUSH17": 0x70,
+	"PUSH18": 0x71,
+	"PUSH19": 0x72,
+	"PUSH20": 0x73,
+	"PUSH21": 0x74,
+	"PUSH22": 0x75,
+	"PUSH23": 0x76,
+	"PUSH24": 0x77,
+	"PUSH25": 0x78,
+	"PUSH26": 0x70,
+	"PUSH27": 0x7a,
+	"PUSH28": 0x7b,
+	"PUSH29": 0x7c,
+	"PUSH30": 0x7d,
+	"PUSH31": 0x7e,
+	"PUSH32": 0x7f,
+
+	// 0xf0 range - closures
+	"CREATE": 0xf0,
+	"CALL":   0xf1,
+	"RETURN": 0xf2,
+
+	// 0x70 range - other
+	"LOG":     0xfe,
+	"SUICIDE": 0x7f,
+}
+
+func IsOpCode(s string) bool {
+	for key, _ := range OpCodes {
+		if key == s {
+			return true
+		}
+	}
+	return false
+}
diff --git a/ethvm/vm.go b/ethvm/vm.go
new file mode 100644
index 000000000..2a83bae3d
--- /dev/null
+++ b/ethvm/vm.go
@@ -0,0 +1,848 @@
+package ethvm
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethcrypto"
+	"github.com/ethereum/eth-go/ethstate"
+	"github.com/ethereum/eth-go/ethutil"
+	"math"
+	"math/big"
+)
+
+type Debugger interface {
+	BreakHook(step int, op OpCode, mem *Memory, stack *Stack, object *ethstate.StateObject) bool
+	StepHook(step int, op OpCode, mem *Memory, stack *Stack, object *ethstate.StateObject) bool
+	BreakPoints() []int64
+	SetCode(byteCode []byte)
+}
+
+type Vm struct {
+	// Stack for processing contracts
+	stack *Stack
+	// non-persistent key/value memory storage
+	mem map[string]*big.Int
+
+	env Environment
+
+	Verbose bool
+
+	logTy  byte
+	logStr string
+
+	err error
+
+	// Debugging
+	Dbg Debugger
+
+	BreakPoints []int64
+	Stepping    bool
+	Fn          string
+}
+
+type Environment interface {
+	State() *ethstate.State
+
+	Origin() []byte
+	BlockNumber() *big.Int
+	PrevHash() []byte
+	Coinbase() []byte
+	Time() int64
+	Difficulty() *big.Int
+	Data() []string
+	Value() *big.Int
+}
+
+type Object interface {
+	GetStorage(key *big.Int) *ethutil.Value
+	SetStorage(key *big.Int, value *ethutil.Value)
+}
+
+func New(env Environment) *Vm {
+	lt := LogTyPretty
+	if ethutil.Config.Diff {
+		lt = LogTyDiff
+	}
+
+	return &Vm{env: env, logTy: lt}
+}
+
+func (self *Vm) RunClosure(closure *Closure) (ret []byte, err error) {
+	// Recover from any require exception
+	defer func() {
+		if r := recover(); r != nil {
+			ret = closure.Return(nil)
+			err = fmt.Errorf("%v", r)
+			vmlogger.Errorln("vm err", err)
+		}
+	}()
+
+	// Debug hook
+	if self.Dbg != nil {
+		self.Dbg.SetCode(closure.Code)
+	}
+
+	// Don't bother with the execution if there's no code.
+	if len(closure.Code) == 0 {
+		return closure.Return(nil), nil
+	}
+
+	vmlogger.Debugf("(%s) %x gas: %v (d) %x\n", self.Fn, closure.Address(), closure.Gas, closure.Args)
+
+	var (
+		op OpCode
+
+		mem      = &Memory{}
+		stack    = NewStack()
+		pc       = big.NewInt(0)
+		step     = 0
+		prevStep = 0
+		require  = func(m int) {
+			if stack.Len() < m {
+				panic(fmt.Sprintf("%04v (%v) stack err size = %d, required = %d", pc, op, stack.Len(), m))
+			}
+		}
+	)
+
+	for {
+		prevStep = step
+		// The base for all big integer arithmetic
+		base := new(big.Int)
+
+		step++
+		// Get the memory location of pc
+		val := closure.Get(pc)
+		// Get the opcode (it must be an opcode!)
+		op = OpCode(val.Uint())
+
+		// XXX Leave this Println intact. Don't change this to the log system.
+		// Used for creating diffs between implementations
+		if self.logTy == LogTyDiff {
+			/*
+				switch op {
+				case STOP, RETURN, SUICIDE:
+					closure.object.EachStorage(func(key string, value *ethutil.Value) {
+						value.Decode()
+						fmt.Printf("%x %x\n", new(big.Int).SetBytes([]byte(key)).Bytes(), value.Bytes())
+					})
+				}
+
+				b := pc.Bytes()
+				if len(b) == 0 {
+					b = []byte{0}
+				}
+
+				fmt.Printf("%x %x %x %x\n", closure.Address(), b, []byte{byte(op)}, closure.Gas.Bytes())
+			*/
+		}
+
+		gas := new(big.Int)
+		addStepGasUsage := func(amount *big.Int) {
+			if amount.Cmp(ethutil.Big0) >= 0 {
+				gas.Add(gas, amount)
+			}
+		}
+
+		addStepGasUsage(GasStep)
+
+		var newMemSize uint64 = 0
+		switch op {
+		case STOP:
+			gas.Set(ethutil.Big0)
+		case SUICIDE:
+			gas.Set(ethutil.Big0)
+		case SLOAD:
+			gas.Set(GasSLoad)
+		case SSTORE:
+			var mult *big.Int
+			y, x := stack.Peekn()
+			val := closure.GetStorage(x)
+			if val.BigInt().Cmp(ethutil.Big0) == 0 && len(y.Bytes()) > 0 {
+				mult = ethutil.Big2
+			} else if val.BigInt().Cmp(ethutil.Big0) != 0 && len(y.Bytes()) == 0 {
+				mult = ethutil.Big0
+			} else {
+				mult = ethutil.Big1
+			}
+			gas = new(big.Int).Mul(mult, GasSStore)
+		case BALANCE:
+			gas.Set(GasBalance)
+		case MSTORE:
+			require(2)
+			newMemSize = stack.Peek().Uint64() + 32
+		case MLOAD:
+			require(1)
+
+			newMemSize = stack.Peek().Uint64() + 32
+		case MSTORE8:
+			require(2)
+			newMemSize = stack.Peek().Uint64() + 1
+		case RETURN:
+			require(2)
+
+			newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-2].Uint64()
+		case SHA3:
+			require(2)
+
+			gas.Set(GasSha)
+
+			newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-2].Uint64()
+		case CALLDATACOPY:
+			require(3)
+
+			newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-3].Uint64()
+		case CODECOPY:
+			require(3)
+
+			newMemSize = stack.Peek().Uint64() + stack.data[stack.Len()-3].Uint64()
+		case CALL:
+			require(7)
+			gas.Set(GasCall)
+			addStepGasUsage(stack.data[stack.Len()-1])
+
+			x := stack.data[stack.Len()-6].Uint64() + stack.data[stack.Len()-7].Uint64()
+			y := stack.data[stack.Len()-4].Uint64() + stack.data[stack.Len()-5].Uint64()
+
+			newMemSize = uint64(math.Max(float64(x), float64(y)))
+		case CREATE:
+			require(3)
+			gas.Set(GasCreate)
+
+			newMemSize = stack.data[stack.Len()-2].Uint64() + stack.data[stack.Len()-3].Uint64()
+		}
+
+		newMemSize = (newMemSize + 31) / 32 * 32
+		if newMemSize > uint64(mem.Len()) {
+			m := GasMemory.Uint64() * (newMemSize - uint64(mem.Len())) / 32
+			addStepGasUsage(big.NewInt(int64(m)))
+		}
+
+		if !closure.UseGas(gas) {
+			err := fmt.Errorf("Insufficient gas for %v. req %v has %v", op, gas, closure.Gas)
+
+			closure.UseGas(closure.Gas)
+
+			return closure.Return(nil), err
+		}
+
+		self.Printf("(pc) %-3d -o- %-14s", pc, op.String())
+		self.Printf(" (g) %-3v (%v)", gas, closure.Gas)
+
+		mem.Resize(newMemSize)
+
+		switch op {
+		case LOG:
+			stack.Print()
+			mem.Print()
+			// 0x20 range
+		case ADD:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v + %v", y, x)
+
+			base.Add(y, x)
+
+			self.Printf(" = %v", base)
+			// Pop result back on the stack
+			stack.Push(base)
+		case SUB:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v - %v", y, x)
+
+			base.Sub(y, x)
+
+			self.Printf(" = %v", base)
+			// Pop result back on the stack
+			stack.Push(base)
+		case MUL:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v * %v", y, x)
+
+			base.Mul(y, x)
+
+			self.Printf(" = %v", base)
+			// Pop result back on the stack
+			stack.Push(base)
+		case DIV:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v / %v", y, x)
+
+			base.Div(y, x)
+
+			self.Printf(" = %v", base)
+			// Pop result back on the stack
+			stack.Push(base)
+		case SDIV:
+			require(2)
+			x, y := stack.Popn()
+			// n > 2**255
+			if x.Cmp(Pow256) > 0 {
+				x.Sub(Pow256, x)
+			}
+			if y.Cmp(Pow256) > 0 {
+				y.Sub(Pow256, y)
+			}
+			z := new(big.Int)
+			z.Div(x, y)
+			if z.Cmp(Pow256) > 0 {
+				z.Sub(Pow256, z)
+			}
+			// Push result on to the stack
+			stack.Push(z)
+		case MOD:
+			require(2)
+			x, y := stack.Popn()
+
+			self.Printf(" %v %% %v", y, x)
+
+			base.Mod(y, x)
+
+			self.Printf(" = %v", base)
+			stack.Push(base)
+		case SMOD:
+			require(2)
+			x, y := stack.Popn()
+			// n > 2**255
+			if x.Cmp(Pow256) > 0 {
+				x.Sub(Pow256, x)
+			}
+			if y.Cmp(Pow256) > 0 {
+				y.Sub(Pow256, y)
+			}
+			z := new(big.Int)
+			z.Mod(x, y)
+			if z.Cmp(Pow256) > 0 {
+				z.Sub(Pow256, z)
+			}
+			// Push result on to the stack
+			stack.Push(z)
+		case EXP:
+			require(2)
+			x, y := stack.Popn()
+
+			self.Printf(" %v ** %v", y, x)
+
+			base.Exp(y, x, Pow256)
+
+			self.Printf(" = %v", base)
+
+			stack.Push(base)
+		case NEG:
+			require(1)
+			base.Sub(Pow256, stack.Pop())
+			stack.Push(base)
+		case LT:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v < %v", y, x)
+			// x < y
+			if y.Cmp(x) < 0 {
+				stack.Push(ethutil.BigTrue)
+			} else {
+				stack.Push(ethutil.BigFalse)
+			}
+		case GT:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v > %v", y, x)
+
+			// x > y
+			if y.Cmp(x) > 0 {
+				stack.Push(ethutil.BigTrue)
+			} else {
+				stack.Push(ethutil.BigFalse)
+			}
+
+		case SLT:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v < %v", y, x)
+			// x < y
+			if y.Cmp(x) < 0 {
+				stack.Push(ethutil.BigTrue)
+			} else {
+				stack.Push(ethutil.BigFalse)
+			}
+		case SGT:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v > %v", y, x)
+
+			// x > y
+			if y.Cmp(x) > 0 {
+				stack.Push(ethutil.BigTrue)
+			} else {
+				stack.Push(ethutil.BigFalse)
+			}
+
+		case EQ:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v == %v", y, x)
+
+			// x == y
+			if x.Cmp(y) == 0 {
+				stack.Push(ethutil.BigTrue)
+			} else {
+				stack.Push(ethutil.BigFalse)
+			}
+		case NOT:
+			require(1)
+			x := stack.Pop()
+			if x.Cmp(ethutil.BigFalse) > 0 {
+				stack.Push(ethutil.BigFalse)
+			} else {
+				stack.Push(ethutil.BigTrue)
+			}
+
+			// 0x10 range
+		case AND:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v & %v", y, x)
+
+			stack.Push(base.And(y, x))
+		case OR:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v | %v", y, x)
+
+			stack.Push(base.Or(y, x))
+		case XOR:
+			require(2)
+			x, y := stack.Popn()
+			self.Printf(" %v ^ %v", y, x)
+
+			stack.Push(base.Xor(y, x))
+		case BYTE:
+			require(2)
+			val, th := stack.Popn()
+			if th.Cmp(big.NewInt(32)) < 0 && th.Cmp(big.NewInt(int64(len(val.Bytes())))) < 0 {
+				byt := big.NewInt(int64(val.Bytes()[th.Int64()]))
+				stack.Push(byt)
+
+				self.Printf(" => 0x%x", byt.Bytes())
+			} else {
+				stack.Push(ethutil.BigFalse)
+			}
+
+			// 0x20 range
+		case SHA3:
+			require(2)
+			size, offset := stack.Popn()
+			data := ethcrypto.Sha3Bin(mem.Get(offset.Int64(), size.Int64()))
+
+			stack.Push(ethutil.BigD(data))
+
+			self.Printf(" => %x", data)
+			// 0x30 range
+		case ADDRESS:
+			stack.Push(ethutil.BigD(closure.Address()))
+
+			self.Printf(" => %x", closure.Address())
+		case BALANCE:
+			require(1)
+
+			addr := stack.Pop().Bytes()
+			balance := self.env.State().GetBalance(addr)
+
+			stack.Push(balance)
+
+			self.Printf(" => %v (%x)", balance, addr)
+		case ORIGIN:
+			origin := self.env.Origin()
+
+			stack.Push(ethutil.BigD(origin))
+
+			self.Printf(" => %x", origin)
+		case CALLER:
+			caller := closure.caller.Address()
+			stack.Push(ethutil.BigD(caller))
+
+			self.Printf(" => %x", caller)
+		case CALLVALUE:
+			value := self.env.Value()
+
+			stack.Push(value)
+
+			self.Printf(" => %v", value)
+		case CALLDATALOAD:
+			require(1)
+			var (
+				offset  = stack.Pop()
+				data    = make([]byte, 32)
+				lenData = big.NewInt(int64(len(closure.Args)))
+			)
+
+			if lenData.Cmp(offset) >= 0 {
+				length := new(big.Int).Add(offset, ethutil.Big32)
+				length = ethutil.BigMin(length, lenData)
+
+				copy(data, closure.Args[offset.Int64():length.Int64()])
+			}
+
+			self.Printf(" => 0x%x", data)
+
+			stack.Push(ethutil.BigD(data))
+		case CALLDATASIZE:
+			l := int64(len(closure.Args))
+			stack.Push(big.NewInt(l))
+
+			self.Printf(" => %d", l)
+		case CALLDATACOPY:
+			var (
+				size = int64(len(closure.Args))
+				mOff = stack.Pop().Int64()
+				cOff = stack.Pop().Int64()
+				l    = stack.Pop().Int64()
+			)
+
+			if cOff > size {
+				cOff = 0
+				l = 0
+			} else if cOff+l > size {
+				l = 0
+			}
+
+			code := closure.Args[cOff : cOff+l]
+
+			mem.Set(mOff, l, code)
+		case CODESIZE:
+			l := big.NewInt(int64(len(closure.Code)))
+			stack.Push(l)
+
+			self.Printf(" => %d", l)
+		case CODECOPY:
+			var (
+				size = int64(len(closure.Code))
+				mOff = stack.Pop().Int64()
+				cOff = stack.Pop().Int64()
+				l    = stack.Pop().Int64()
+			)
+
+			if cOff > size {
+				cOff = 0
+				l = 0
+			} else if cOff+l > size {
+				l = 0
+			}
+
+			code := closure.Code[cOff : cOff+l]
+			//fmt.Println("len:", l, "code off:", cOff, "mem off:", mOff)
+
+			mem.Set(mOff, l, code)
+			//fmt.Println(Code(mem.Get(mOff, l)))
+		case GASPRICE:
+			stack.Push(closure.Price)
+
+			self.Printf(" => %v", closure.Price)
+
+			// 0x40 range
+		case PREVHASH:
+			prevHash := self.env.PrevHash()
+
+			stack.Push(ethutil.BigD(prevHash))
+
+			self.Printf(" => 0x%x", prevHash)
+		case COINBASE:
+			coinbase := self.env.Coinbase()
+
+			stack.Push(ethutil.BigD(coinbase))
+
+			self.Printf(" => 0x%x", coinbase)
+		case TIMESTAMP:
+			time := self.env.Time()
+
+			stack.Push(big.NewInt(time))
+
+			self.Printf(" => 0x%x", time)
+		case NUMBER:
+			number := self.env.BlockNumber()
+
+			stack.Push(number)
+
+			self.Printf(" => 0x%x", number.Bytes())
+		case DIFFICULTY:
+			difficulty := self.env.Difficulty()
+
+			stack.Push(difficulty)
+
+			self.Printf(" => 0x%x", difficulty.Bytes())
+		case GASLIMIT:
+			// TODO
+			stack.Push(big.NewInt(0))
+
+			// 0x50 range
+		case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
+			a := big.NewInt(int64(op) - int64(PUSH1) + 1)
+			pc.Add(pc, ethutil.Big1)
+			data := closure.Gets(pc, a)
+			val := ethutil.BigD(data.Bytes())
+			// Push value to stack
+			stack.Push(val)
+			pc.Add(pc, a.Sub(a, big.NewInt(1)))
+
+			step += int(op) - int(PUSH1) + 1
+
+			self.Printf(" => 0x%x", data.Bytes())
+		case POP:
+			require(1)
+			stack.Pop()
+		case DUP:
+			require(1)
+			stack.Push(stack.Peek())
+
+			self.Printf(" => 0x%x", stack.Peek().Bytes())
+		case SWAP:
+			require(2)
+			x, y := stack.Popn()
+			stack.Push(y)
+			stack.Push(x)
+		case MLOAD:
+			require(1)
+			offset := stack.Pop()
+			val := ethutil.BigD(mem.Get(offset.Int64(), 32))
+			stack.Push(val)
+
+			self.Printf(" => 0x%x", val.Bytes())
+		case MSTORE: // Store the value at stack top-1 in to memory at location stack top
+			require(2)
+			// Pop value of the stack
+			val, mStart := stack.Popn()
+			mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(val, 256))
+
+			self.Printf(" => 0x%x", val)
+		case MSTORE8:
+			require(2)
+			val, mStart := stack.Popn()
+			//base.And(val, new(big.Int).SetInt64(0xff))
+			//mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(base, 256))
+			mem.store[mStart.Int64()] = byte(val.Int64() & 0xff)
+
+			self.Printf(" => 0x%x", val)
+		case SLOAD:
+			require(1)
+			loc := stack.Pop()
+			val := closure.GetStorage(loc)
+
+			stack.Push(val.BigInt())
+
+			self.Printf(" {0x%x : 0x%x}", loc.Bytes(), val.Bytes())
+		case SSTORE:
+			require(2)
+			val, loc := stack.Popn()
+			closure.SetStorage(loc, ethutil.NewValue(val))
+
+			// Add the change to manifest
+			self.env.State().Manifest().AddStorageChange(closure.Object(), loc.Bytes(), val)
+
+			self.Printf(" {0x%x : 0x%x}", loc, val)
+		case JUMP:
+			require(1)
+			pc = stack.Pop()
+			// Reduce pc by one because of the increment that's at the end of this for loop
+			self.Printf(" ~> %v", pc).Endl()
+
+			continue
+		case JUMPI:
+			require(2)
+			cond, pos := stack.Popn()
+			if cond.Cmp(ethutil.BigTrue) >= 0 {
+				pc = pos
+
+				self.Printf(" ~> %v (t)", pc).Endl()
+
+				continue
+			} else {
+				self.Printf(" (f)")
+			}
+		case PC:
+			stack.Push(pc)
+		case MSIZE:
+			stack.Push(big.NewInt(int64(mem.Len())))
+		case GAS:
+			stack.Push(closure.Gas)
+			// 0x60 range
+		case CREATE:
+			require(3)
+
+			var (
+				err          error
+				value        = stack.Pop()
+				size, offset = stack.Popn()
+
+				// Snapshot the current stack so we are able to
+				// revert back to it later.
+				snapshot = self.env.State().Copy()
+			)
+
+			// Generate a new address
+			addr := ethcrypto.CreateAddress(closure.Address(), closure.object.Nonce)
+			for i := uint64(0); self.env.State().GetStateObject(addr) != nil; i++ {
+				ethcrypto.CreateAddress(closure.Address(), closure.object.Nonce+i)
+			}
+			closure.object.Nonce++
+
+			self.Printf(" (*) %x", addr).Endl()
+
+			// Create a new contract
+			contract := self.env.State().NewStateObject(addr)
+			if contract.Amount.Cmp(value) >= 0 {
+				closure.object.SubAmount(value)
+				contract.AddAmount(value)
+
+				// Set the init script
+				initCode := mem.Get(offset.Int64(), size.Int64())
+				//fmt.Printf("%x\n", initCode)
+				// Transfer all remaining gas to the new
+				// contract so it may run the init script
+				gas := new(big.Int).Set(closure.Gas)
+				closure.UseGas(closure.Gas)
+
+				// Create the closure
+				c := NewClosure(closure, contract, initCode, gas, closure.Price)
+				// Call the closure and set the return value as
+				// main script.
+				contract.Code, _, err = c.Call(self, nil)
+			} else {
+				err = fmt.Errorf("Insufficient funds to transfer value. Req %v, has %v", value, closure.object.Amount)
+			}
+
+			if err != nil {
+				stack.Push(ethutil.BigFalse)
+
+				// Revert the state as it was before.
+				self.env.State().Set(snapshot)
+
+				self.Printf("CREATE err %v", err)
+			} else {
+				stack.Push(ethutil.BigD(addr))
+				self.Printf("CREATE success")
+			}
+			self.Endl()
+
+			// Debug hook
+			if self.Dbg != nil {
+				self.Dbg.SetCode(closure.Code)
+			}
+		case CALL:
+			require(7)
+
+			self.Endl()
+
+			gas := stack.Pop()
+			// Pop gas and value of the stack.
+			value, addr := stack.Popn()
+			// Pop input size and offset
+			inSize, inOffset := stack.Popn()
+			// Pop return size and offset
+			retSize, retOffset := stack.Popn()
+
+			// Get the arguments from the memory
+			args := mem.Get(inOffset.Int64(), inSize.Int64())
+
+			if closure.object.Amount.Cmp(value) < 0 {
+				vmlogger.Debugf("Insufficient funds to transfer value. Req %v, has %v", value, closure.object.Amount)
+
+				closure.ReturnGas(gas, nil)
+
+				stack.Push(ethutil.BigFalse)
+			} else {
+				snapshot := self.env.State().Copy()
+
+				stateObject := self.env.State().GetOrNewStateObject(addr.Bytes())
+
+				closure.object.SubAmount(value)
+				stateObject.AddAmount(value)
+
+				// Create a new callable closure
+				c := NewClosure(closure, stateObject, stateObject.Code, gas, closure.Price)
+				// Executer the closure and get the return value (if any)
+				ret, _, err := c.Call(self, args)
+				if err != nil {
+					stack.Push(ethutil.BigFalse)
+
+					vmlogger.Debugf("Closure execution failed. %v\n", err)
+
+					self.env.State().Set(snapshot)
+				} else {
+					stack.Push(ethutil.BigTrue)
+
+					mem.Set(retOffset.Int64(), retSize.Int64(), ret)
+				}
+
+				// Debug hook
+				if self.Dbg != nil {
+					self.Dbg.SetCode(closure.Code)
+				}
+			}
+		case RETURN:
+			require(2)
+			size, offset := stack.Popn()
+			ret := mem.Get(offset.Int64(), size.Int64())
+
+			self.Printf(" => (%d) 0x%x", len(ret), ret).Endl()
+
+			return closure.Return(ret), nil
+		case SUICIDE:
+			require(1)
+
+			receiver := self.env.State().GetOrNewStateObject(stack.Pop().Bytes())
+
+			receiver.AddAmount(closure.object.Amount)
+
+			closure.object.MarkForDeletion()
+
+			fallthrough
+		case STOP: // Stop the closure
+			self.Endl()
+
+			return closure.Return(nil), nil
+		default:
+			vmlogger.Debugf("(pc) %-3v Invalid opcode %x\n", pc, op)
+			fmt.Println(ethstate.Code(closure.Code))
+
+			return closure.Return(nil), fmt.Errorf("Invalid opcode %x", op)
+		}
+
+		pc.Add(pc, ethutil.Big1)
+
+		self.Endl()
+
+		if self.Dbg != nil {
+			for _, instrNo := range self.Dbg.BreakPoints() {
+				if pc.Cmp(big.NewInt(instrNo)) == 0 {
+					self.Stepping = true
+
+					if !self.Dbg.BreakHook(prevStep, op, mem, stack, closure.Object()) {
+						return nil, nil
+					}
+				} else if self.Stepping {
+					if !self.Dbg.StepHook(prevStep, op, mem, stack, closure.Object()) {
+						return nil, nil
+					}
+				}
+			}
+		}
+
+	}
+}
+
+func (self *Vm) Printf(format string, v ...interface{}) *Vm {
+	if self.Verbose && self.logTy == LogTyPretty {
+		self.logStr += fmt.Sprintf(format, v...)
+	}
+
+	return self
+}
+
+func (self *Vm) Endl() *Vm {
+	if self.Verbose && self.logTy == LogTyPretty {
+		vmlogger.Debugln(self.logStr)
+		self.logStr = ""
+	}
+
+	return self
+}
diff --git a/ethvm/vm_test.go b/ethvm/vm_test.go
new file mode 100644
index 000000000..f0bdc8e2c
--- /dev/null
+++ b/ethvm/vm_test.go
@@ -0,0 +1,48 @@
+package ethvm
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethdb"
+	"github.com/ethereum/eth-go/ethlog"
+	"github.com/ethereum/eth-go/ethstate"
+	"github.com/ethereum/eth-go/ethutil"
+	"log"
+	"math/big"
+	"os"
+	"testing"
+)
+
+type TestEnv struct {
+}
+
+func (self TestEnv) GetObject() Object               { return nil }
+func (self TestEnv) Origin() []byte                  { return nil }
+func (self TestEnv) BlockNumber() *big.Int           { return nil }
+func (self TestEnv) PrevHash() []byte                { return nil }
+func (self TestEnv) Coinbase() []byte                { return nil }
+func (self TestEnv) Time() int64                     { return 0 }
+func (self TestEnv) Difficulty() *big.Int            { return nil }
+func (self TestEnv) Data() []string                  { return nil }
+func (self TestEnv) Value() *big.Int                 { return nil }
+func (self TestEnv) GetBalance(addr []byte) *big.Int { return nil }
+func (self TestEnv) State() *ethstate.State          { return nil }
+
+func TestVm(t *testing.T) {
+	ethlog.AddLogSystem(ethlog.NewStdLogSystem(os.Stdout, log.LstdFlags, ethlog.LogLevel(4)))
+
+	db, _ := ethdb.NewMemDatabase()
+	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
+	ethutil.Config.Db = db
+
+	stateObject := ethstate.NewStateObject([]byte{'j', 'e', 'f', 'f'})
+	callerClosure := NewClosure(stateObject, stateObject, []byte{0x60, 0x01}, big.NewInt(1000000), big.NewInt(0))
+
+	vm := New(TestEnv{})
+	vm.Verbose = true
+
+	ret, _, e := callerClosure.Call(vm, nil)
+	if e != nil {
+		fmt.Println("error", e)
+	}
+	fmt.Println(ret)
+}