cmd, consensus, eth: split ethash related config to it own (#15520)

* cmd, consensus, eth: split ethash related config to it own

* eth, consensus: minor polish

* eth, consenus, console: compress pow testing config field to single one

* consensus, eth: document pow mode

10 files changed, 154 insertions, 129 deletions

diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 5c2929268..9fbad8dab 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -217,27 +217,27 @@ var (
 	EthashCachesInMemoryFlag = cli.IntFlag{
 		Name:  "ethash.cachesinmem",
 		Usage: "Number of recent ethash caches to keep in memory (16MB each)",
-		Value: eth.DefaultConfig.EthashCachesInMem,
+		Value: eth.DefaultConfig.Ethash.CachesInMem,
 	}
 	EthashCachesOnDiskFlag = cli.IntFlag{
 		Name:  "ethash.cachesondisk",
 		Usage: "Number of recent ethash caches to keep on disk (16MB each)",
-		Value: eth.DefaultConfig.EthashCachesOnDisk,
+		Value: eth.DefaultConfig.Ethash.CachesOnDisk,
 	}
 	EthashDatasetDirFlag = DirectoryFlag{
 		Name:  "ethash.dagdir",
 		Usage: "Directory to store the ethash mining DAGs (default = inside home folder)",
-		Value: DirectoryString{eth.DefaultConfig.EthashDatasetDir},
+		Value: DirectoryString{eth.DefaultConfig.Ethash.DatasetDir},
 	}
 	EthashDatasetsInMemoryFlag = cli.IntFlag{
 		Name:  "ethash.dagsinmem",
 		Usage: "Number of recent ethash mining DAGs to keep in memory (1+GB each)",
-		Value: eth.DefaultConfig.EthashDatasetsInMem,
+		Value: eth.DefaultConfig.Ethash.DatasetsInMem,
 	}
 	EthashDatasetsOnDiskFlag = cli.IntFlag{
 		Name:  "ethash.dagsondisk",
 		Usage: "Number of recent ethash mining DAGs to keep on disk (1+GB each)",
-		Value: eth.DefaultConfig.EthashDatasetsOnDisk,
+		Value: eth.DefaultConfig.Ethash.DatasetsOnDisk,
 	}
 	// Transaction pool settings
 	TxPoolNoLocalsFlag = cli.BoolFlag{
@@ -910,22 +910,22 @@ func setTxPool(ctx *cli.Context, cfg *core.TxPoolConfig) {
 
 func setEthash(ctx *cli.Context, cfg *eth.Config) {
 	if ctx.GlobalIsSet(EthashCacheDirFlag.Name) {
-		cfg.EthashCacheDir = ctx.GlobalString(EthashCacheDirFlag.Name)
+		cfg.Ethash.CacheDir = ctx.GlobalString(EthashCacheDirFlag.Name)
 	}
 	if ctx.GlobalIsSet(EthashDatasetDirFlag.Name) {
-		cfg.EthashDatasetDir = ctx.GlobalString(EthashDatasetDirFlag.Name)
+		cfg.Ethash.DatasetDir = ctx.GlobalString(EthashDatasetDirFlag.Name)
 	}
 	if ctx.GlobalIsSet(EthashCachesInMemoryFlag.Name) {
-		cfg.EthashCachesInMem = ctx.GlobalInt(EthashCachesInMemoryFlag.Name)
+		cfg.Ethash.CachesInMem = ctx.GlobalInt(EthashCachesInMemoryFlag.Name)
 	}
 	if ctx.GlobalIsSet(EthashCachesOnDiskFlag.Name) {
-		cfg.EthashCachesOnDisk = ctx.GlobalInt(EthashCachesOnDiskFlag.Name)
+		cfg.Ethash.CachesOnDisk = ctx.GlobalInt(EthashCachesOnDiskFlag.Name)
 	}
 	if ctx.GlobalIsSet(EthashDatasetsInMemoryFlag.Name) {
-		cfg.EthashDatasetsInMem = ctx.GlobalInt(EthashDatasetsInMemoryFlag.Name)
+		cfg.Ethash.DatasetsInMem = ctx.GlobalInt(EthashDatasetsInMemoryFlag.Name)
 	}
 	if ctx.GlobalIsSet(EthashDatasetsOnDiskFlag.Name) {
-		cfg.EthashDatasetsOnDisk = ctx.GlobalInt(EthashDatasetsOnDiskFlag.Name)
+		cfg.Ethash.DatasetsOnDisk = ctx.GlobalInt(EthashDatasetsOnDiskFlag.Name)
 	}
 }
 
@@ -1159,10 +1159,14 @@ func MakeChain(ctx *cli.Context, stack *node.Node) (chain *core.BlockChain, chai
 	} else {
 		engine = ethash.NewFaker()
 		if !ctx.GlobalBool(FakePoWFlag.Name) {
-			engine = ethash.New(
-				stack.ResolvePath(eth.DefaultConfig.EthashCacheDir), eth.DefaultConfig.EthashCachesInMem, eth.DefaultConfig.EthashCachesOnDisk,
-				stack.ResolvePath(eth.DefaultConfig.EthashDatasetDir), eth.DefaultConfig.EthashDatasetsInMem, eth.DefaultConfig.EthashDatasetsOnDisk,
-			)
+			engine = ethash.New(ethash.Config{
+				CacheDir:       stack.ResolvePath(eth.DefaultConfig.Ethash.CacheDir),
+				CachesInMem:    eth.DefaultConfig.Ethash.CachesInMem,
+				CachesOnDisk:   eth.DefaultConfig.Ethash.CachesOnDisk,
+				DatasetDir:     stack.ResolvePath(eth.DefaultConfig.Ethash.DatasetDir),
+				DatasetsInMem:  eth.DefaultConfig.Ethash.DatasetsInMem,
+				DatasetsOnDisk: eth.DefaultConfig.Ethash.DatasetsOnDisk,
+			})
 		}
 	}
 	vmcfg := vm.Config{EnablePreimageRecording: ctx.GlobalBool(VMEnableDebugFlag.Name)}
diff --git a/consensus/ethash/algorithm_test.go b/consensus/ethash/algorithm_test.go
index 7e4307a74..7765ff9fe 100644
--- a/consensus/ethash/algorithm_test.go
+++ b/consensus/ethash/algorithm_test.go
@@ -703,8 +703,7 @@ func TestConcurrentDiskCacheGeneration(t *testing.T) {
 
 		go func(idx int) {
 			defer pend.Done()
-
-			ethash := New(cachedir, 0, 1, "", 0, 0)
+			ethash := New(Config{cachedir, 0, 1, "", 0, 0, ModeNormal})
 			if err := ethash.VerifySeal(nil, block.Header()); err != nil {
 				t.Errorf("proc %d: block verification failed: %v", idx, err)
 			}
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index e330b7ce5..775419e06 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -68,7 +68,7 @@ func (ethash *Ethash) Author(header *types.Header) (common.Address, error) {
 // stock Ethereum ethash engine.
 func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error {
 	// If we're running a full engine faking, accept any input as valid
-	if ethash.fakeFull {
+	if ethash.config.PowMode == ModeFullFake {
 		return nil
 	}
 	// Short circuit if the header is known, or it's parent not
@@ -89,7 +89,7 @@ func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.He
 // a results channel to retrieve the async verifications.
 func (ethash *Ethash) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
 	// If we're running a full engine faking, accept any input as valid
-	if ethash.fakeFull || len(headers) == 0 {
+	if ethash.config.PowMode == ModeFullFake || len(headers) == 0 {
 		abort, results := make(chan struct{}), make(chan error, len(headers))
 		for i := 0; i < len(headers); i++ {
 			results <- nil
@@ -169,7 +169,7 @@ func (ethash *Ethash) verifyHeaderWorker(chain consensus.ChainReader, headers []
 // rules of the stock Ethereum ethash engine.
 func (ethash *Ethash) VerifyUncles(chain consensus.ChainReader, block *types.Block) error {
 	// If we're running a full engine faking, accept any input as valid
-	if ethash.fakeFull {
+	if ethash.config.PowMode == ModeFullFake {
 		return nil
 	}
 	// Verify that there are at most 2 uncles included in this block
@@ -455,7 +455,7 @@ func calcDifficultyFrontier(time uint64, parent *types.Header) *big.Int {
 // the PoW difficulty requirements.
 func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Header) error {
 	// If we're running a fake PoW, accept any seal as valid
-	if ethash.fakeMode {
+	if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
 		time.Sleep(ethash.fakeDelay)
 		if ethash.fakeFail == header.Number.Uint64() {
 			return errInvalidPoW
@@ -480,7 +480,7 @@ func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Head
 	cache := ethash.cache(number)
 
 	size := datasetSize(number)
-	if ethash.tester {
+	if ethash.config.PowMode == ModeTest {
 		size = 32 * 1024
 	}
 	digest, result := hashimotoLight(size, cache, header.HashNoNonce().Bytes(), header.Nonce.Uint64())
diff --git a/consensus/ethash/ethash.go b/consensus/ethash/ethash.go
index dd6147072..a78b3a895 100644
--- a/consensus/ethash/ethash.go
+++ b/consensus/ethash/ethash.go
@@ -45,7 +45,7 @@ var (
 	maxUint256 = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
 
 	// sharedEthash is a full instance that can be shared between multiple users.
-	sharedEthash = New("", 3, 0, "", 1, 0)
+	sharedEthash = New(Config{"", 3, 0, "", 1, 0, ModeNormal})
 
 	// algorithmRevision is the data structure version used for file naming.
 	algorithmRevision = 23
@@ -320,15 +320,32 @@ func MakeDataset(block uint64, dir string) {
 	d.release()
 }
 
+// Mode defines the type and amount of PoW verification an ethash engine makes.
+type Mode uint
+
+const (
+	ModeNormal Mode = iota
+	ModeShared
+	ModeTest
+	ModeFake
+	ModeFullFake
+)
+
+// Config are the configuration parameters of the ethash.
+type Config struct {
+	CacheDir       string
+	CachesInMem    int
+	CachesOnDisk   int
+	DatasetDir     string
+	DatasetsInMem  int
+	DatasetsOnDisk int
+	PowMode        Mode
+}
+
 // Ethash is a consensus engine based on proot-of-work implementing the ethash
 // algorithm.
 type Ethash struct {
-	cachedir     string // Data directory to store the verification caches
-	cachesinmem  int    // Number of caches to keep in memory
-	cachesondisk int    // Number of caches to keep on disk
-	dagdir       string // Data directory to store full mining datasets
-	dagsinmem    int    // Number of mining datasets to keep in memory
-	dagsondisk   int    // Number of mining datasets to keep on disk
+	config Config
 
 	caches   map[uint64]*cache   // In memory caches to avoid regenerating too often
 	fcache   *cache              // Pre-generated cache for the estimated future epoch
@@ -342,10 +359,7 @@ type Ethash struct {
 	hashrate metrics.Meter // Meter tracking the average hashrate
 
 	// The fields below are hooks for testing
-	tester    bool          // Flag whether to use a smaller test dataset
 	shared    *Ethash       // Shared PoW verifier to avoid cache regeneration
-	fakeMode  bool          // Flag whether to disable PoW checking
-	fakeFull  bool          // Flag whether to disable all consensus rules
 	fakeFail  uint64        // Block number which fails PoW check even in fake mode
 	fakeDelay time.Duration // Time delay to sleep for before returning from verify
 
@@ -353,28 +367,23 @@ type Ethash struct {
 }
 
 // New creates a full sized ethash PoW scheme.
-func New(cachedir string, cachesinmem, cachesondisk int, dagdir string, dagsinmem, dagsondisk int) *Ethash {
-	if cachesinmem <= 0 {
-		log.Warn("One ethash cache must always be in memory", "requested", cachesinmem)
-		cachesinmem = 1
+func New(config Config) *Ethash {
+	if config.CachesInMem <= 0 {
+		log.Warn("One ethash cache must always be in memory", "requested", config.CachesInMem)
+		config.CachesInMem = 1
 	}
-	if cachedir != "" && cachesondisk > 0 {
-		log.Info("Disk storage enabled for ethash caches", "dir", cachedir, "count", cachesondisk)
+	if config.CacheDir != "" && config.CachesOnDisk > 0 {
+		log.Info("Disk storage enabled for ethash caches", "dir", config.CacheDir, "count", config.CachesOnDisk)
 	}
-	if dagdir != "" && dagsondisk > 0 {
-		log.Info("Disk storage enabled for ethash DAGs", "dir", dagdir, "count", dagsondisk)
+	if config.DatasetDir != "" && config.DatasetsOnDisk > 0 {
+		log.Info("Disk storage enabled for ethash DAGs", "dir", config.DatasetDir, "count", config.DatasetsOnDisk)
 	}
 	return &Ethash{
-		cachedir:     cachedir,
-		cachesinmem:  cachesinmem,
-		cachesondisk: cachesondisk,
-		dagdir:       dagdir,
-		dagsinmem:    dagsinmem,
-		dagsondisk:   dagsondisk,
-		caches:       make(map[uint64]*cache),
-		datasets:     make(map[uint64]*dataset),
-		update:       make(chan struct{}),
-		hashrate:     metrics.NewMeter(),
+		config:   config,
+		caches:   make(map[uint64]*cache),
+		datasets: make(map[uint64]*dataset),
+		update:   make(chan struct{}),
+		hashrate: metrics.NewMeter(),
 	}
 }
 
@@ -382,12 +391,14 @@ func New(cachedir string, cachesinmem, cachesondisk int, dagdir string, dagsinme
 // purposes.
 func NewTester() *Ethash {
 	return &Ethash{
-		cachesinmem: 1,
-		caches:      make(map[uint64]*cache),
-		datasets:    make(map[uint64]*dataset),
-		tester:      true,
-		update:      make(chan struct{}),
-		hashrate:    metrics.NewMeter(),
+		config: Config{
+			CachesInMem: 1,
+			PowMode:     ModeTest,
+		},
+		caches:   make(map[uint64]*cache),
+		datasets: make(map[uint64]*dataset),
+		update:   make(chan struct{}),
+		hashrate: metrics.NewMeter(),
 	}
 }
 
@@ -395,27 +406,45 @@ func NewTester() *Ethash {
 // all blocks' seal as valid, though they still have to conform to the Ethereum
 // consensus rules.
 func NewFaker() *Ethash {
-	return &Ethash{fakeMode: true}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFake,
+		},
+	}
 }
 
 // NewFakeFailer creates a ethash consensus engine with a fake PoW scheme that
 // accepts all blocks as valid apart from the single one specified, though they
 // still have to conform to the Ethereum consensus rules.
 func NewFakeFailer(fail uint64) *Ethash {
-	return &Ethash{fakeMode: true, fakeFail: fail}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFake,
+		},
+		fakeFail: fail,
+	}
 }
 
 // NewFakeDelayer creates a ethash consensus engine with a fake PoW scheme that
 // accepts all blocks as valid, but delays verifications by some time, though
 // they still have to conform to the Ethereum consensus rules.
 func NewFakeDelayer(delay time.Duration) *Ethash {
-	return &Ethash{fakeMode: true, fakeDelay: delay}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFake,
+		},
+		fakeDelay: delay,
+	}
 }
 
 // NewFullFaker creates an ethash consensus engine with a full fake scheme that
 // accepts all blocks as valid, without checking any consensus rules whatsoever.
 func NewFullFaker() *Ethash {
-	return &Ethash{fakeMode: true, fakeFull: true}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFullFake,
+		},
+	}
 }
 
 // NewShared creates a full sized ethash PoW shared between all requesters running
@@ -436,7 +465,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 	current, future := ethash.caches[epoch], (*cache)(nil)
 	if current == nil {
 		// No in-memory cache, evict the oldest if the cache limit was reached
-		for len(ethash.caches) > 0 && len(ethash.caches) >= ethash.cachesinmem {
+		for len(ethash.caches) > 0 && len(ethash.caches) >= ethash.config.CachesInMem {
 			var evict *cache
 			for _, cache := range ethash.caches {
 				if evict == nil || evict.used.After(cache.used) {
@@ -473,7 +502,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 	ethash.lock.Unlock()
 
 	// Wait for generation finish, bump the timestamp and finalize the cache
-	current.generate(ethash.cachedir, ethash.cachesondisk, ethash.tester)
+	current.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
 
 	current.lock.Lock()
 	current.used = time.Now()
@@ -481,7 +510,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 
 	// If we exhausted the future cache, now's a good time to regenerate it
 	if future != nil {
-		go future.generate(ethash.cachedir, ethash.cachesondisk, ethash.tester)
+		go future.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
 	}
 	return current.cache
 }
@@ -498,7 +527,7 @@ func (ethash *Ethash) dataset(block uint64) []uint32 {
 	current, future := ethash.datasets[epoch], (*dataset)(nil)
 	if current == nil {
 		// No in-memory dataset, evict the oldest if the dataset limit was reached
-		for len(ethash.datasets) > 0 && len(ethash.datasets) >= ethash.dagsinmem {
+		for len(ethash.datasets) > 0 && len(ethash.datasets) >= ethash.config.DatasetsInMem {
 			var evict *dataset
 			for _, dataset := range ethash.datasets {
 				if evict == nil || evict.used.After(dataset.used) {
@@ -536,7 +565,7 @@ func (ethash *Ethash) dataset(block uint64) []uint32 {
 	ethash.lock.Unlock()
 
 	// Wait for generation finish, bump the timestamp and finalize the cache
-	current.generate(ethash.dagdir, ethash.dagsondisk, ethash.tester)
+	current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
 
 	current.lock.Lock()
 	current.used = time.Now()
@@ -544,7 +573,7 @@ func (ethash *Ethash) dataset(block uint64) []uint32 {
 
 	// If we exhausted the future dataset, now's a good time to regenerate it
 	if future != nil {
-		go future.generate(ethash.dagdir, ethash.dagsondisk, ethash.tester)
+		go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
 	}
 	return current.dataset
 }
diff --git a/consensus/ethash/sealer.go b/consensus/ethash/sealer.go
index 784e8f649..c2447e473 100644
--- a/consensus/ethash/sealer.go
+++ b/consensus/ethash/sealer.go
@@ -34,7 +34,7 @@ import (
 // the block's difficulty requirements.
 func (ethash *Ethash) Seal(chain consensus.ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error) {
 	// If we're running a fake PoW, simply return a 0 nonce immediately
-	if ethash.fakeMode {
+	if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
 		header := block.Header()
 		header.Nonce, header.MixDigest = types.BlockNonce{}, common.Hash{}
 		return block.WithSeal(header), nil
diff --git a/console/console_test.go b/console/console_test.go
index a159b62bb..d29680785 100644
--- a/console/console_test.go
+++ b/console/console_test.go
@@ -27,6 +27,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/internal/jsre"
@@ -96,7 +97,9 @@ func newTester(t *testing.T, confOverride func(*eth.Config)) *tester {
 	ethConf := &eth.Config{
 		Genesis:   core.DeveloperGenesisBlock(15, common.Address{}),
 		Etherbase: common.HexToAddress(testAddress),
-		PowTest:   true,
+		Ethash: ethash.Config{
+			PowMode: ethash.ModeTest,
+		},
 	}
 	if confOverride != nil {
 		confOverride(ethConf)
diff --git a/eth/backend.go b/eth/backend.go
index 1cd9e8fff..e7f0f57dd 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -125,7 +125,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		chainConfig:    chainConfig,
 		eventMux:       ctx.EventMux,
 		accountManager: ctx.AccountManager,
-		engine:         CreateConsensusEngine(ctx, config, chainConfig, chainDb),
+		engine:         CreateConsensusEngine(ctx, &config.Ethash, chainConfig, chainDb),
 		shutdownChan:   make(chan bool),
 		stopDbUpgrade:  stopDbUpgrade,
 		networkId:      config.NetworkId,
@@ -209,25 +209,31 @@ func CreateDB(ctx *node.ServiceContext, config *Config, name string) (ethdb.Data
 }
 
 // CreateConsensusEngine creates the required type of consensus engine instance for an Ethereum service
-func CreateConsensusEngine(ctx *node.ServiceContext, config *Config, chainConfig *params.ChainConfig, db ethdb.Database) consensus.Engine {
+func CreateConsensusEngine(ctx *node.ServiceContext, config *ethash.Config, chainConfig *params.ChainConfig, db ethdb.Database) consensus.Engine {
 	// If proof-of-authority is requested, set it up
 	if chainConfig.Clique != nil {
 		return clique.New(chainConfig.Clique, db)
 	}
 	// Otherwise assume proof-of-work
 	switch {
-	case config.PowFake:
+	case config.PowMode == ethash.ModeFake:
 		log.Warn("Ethash used in fake mode")
 		return ethash.NewFaker()
-	case config.PowTest:
+	case config.PowMode == ethash.ModeTest:
 		log.Warn("Ethash used in test mode")
 		return ethash.NewTester()
-	case config.PowShared:
+	case config.PowMode == ethash.ModeShared:
 		log.Warn("Ethash used in shared mode")
 		return ethash.NewShared()
 	default:
-		engine := ethash.New(ctx.ResolvePath(config.EthashCacheDir), config.EthashCachesInMem, config.EthashCachesOnDisk,
-			config.EthashDatasetDir, config.EthashDatasetsInMem, config.EthashDatasetsOnDisk)
+		engine := ethash.New(ethash.Config{
+			CacheDir:       ctx.ResolvePath(config.CacheDir),
+			CachesInMem:    config.CachesInMem,
+			CachesOnDisk:   config.CachesOnDisk,
+			DatasetDir:     config.DatasetDir,
+			DatasetsInMem:  config.DatasetsInMem,
+			DatasetsOnDisk: config.DatasetsOnDisk,
+		})
 		engine.SetThreads(-1) // Disable CPU mining
 		return engine
 	}
diff --git a/eth/config.go b/eth/config.go
index 7bcfd403e..383cd6783 100644
--- a/eth/config.go
+++ b/eth/config.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
@@ -33,16 +34,18 @@ import (
 
 // DefaultConfig contains default settings for use on the Ethereum main net.
 var DefaultConfig = Config{
-	SyncMode:             downloader.FastSync,
-	EthashCacheDir:       "ethash",
-	EthashCachesInMem:    2,
-	EthashCachesOnDisk:   3,
-	EthashDatasetsInMem:  1,
-	EthashDatasetsOnDisk: 2,
-	NetworkId:            1,
-	LightPeers:           20,
-	DatabaseCache:        128,
-	GasPrice:             big.NewInt(18 * params.Shannon),
+	SyncMode: downloader.FastSync,
+	Ethash: ethash.Config{
+		CacheDir:       "ethash",
+		CachesInMem:    2,
+		CachesOnDisk:   3,
+		DatasetsInMem:  1,
+		DatasetsOnDisk: 2,
+	},
+	NetworkId:     1,
+	LightPeers:    20,
+	DatabaseCache: 128,
+	GasPrice:      big.NewInt(18 * params.Shannon),
 
 	TxPool: core.DefaultTxPoolConfig,
 	GPO: gasprice.Config{
@@ -59,9 +62,9 @@ func init() {
 		}
 	}
 	if runtime.GOOS == "windows" {
-		DefaultConfig.EthashDatasetDir = filepath.Join(home, "AppData", "Ethash")
+		DefaultConfig.Ethash.DatasetDir = filepath.Join(home, "AppData", "Ethash")
 	} else {
-		DefaultConfig.EthashDatasetDir = filepath.Join(home, ".ethash")
+		DefaultConfig.Ethash.DatasetDir = filepath.Join(home, ".ethash")
 	}
 }
 
@@ -92,12 +95,7 @@ type Config struct {
 	GasPrice     *big.Int
 
 	// Ethash options
-	EthashCacheDir       string
-	EthashCachesInMem    int
-	EthashCachesOnDisk   int
-	EthashDatasetDir     string
-	EthashDatasetsInMem  int
-	EthashDatasetsOnDisk int
+	Ethash ethash.Config
 
 	// Transaction pool options
 	TxPool core.TxPoolConfig
@@ -109,10 +107,7 @@ type Config struct {
 	EnablePreimageRecording bool
 
 	// Miscellaneous options
-	DocRoot   string `toml:"-"`
-	PowFake   bool   `toml:"-"`
-	PowTest   bool   `toml:"-"`
-	PowShared bool   `toml:"-"`
+	DocRoot string `toml:"-"`
 }
 
 type configMarshaling struct {
diff --git a/eth/gen_config.go b/eth/gen_config.go
index 4a4cd7b9c..e2d50e1f6 100644
--- a/eth/gen_config.go
+++ b/eth/gen_config.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
@@ -36,10 +37,8 @@ func (c Config) MarshalTOML() (interface{}, error) {
 		TxPool                  core.TxPoolConfig
 		GPO                     gasprice.Config
 		EnablePreimageRecording bool
-		DocRoot                 string `toml:"-"`
-		PowFake                 bool   `toml:"-"`
-		PowTest                 bool   `toml:"-"`
-		PowShared               bool   `toml:"-"`
+		DocRoot                 string      `toml:"-"`
+		PowMode                 ethash.Mode `toml:"-"`
 	}
 	var enc Config
 	enc.Genesis = c.Genesis
@@ -54,19 +53,17 @@ func (c Config) MarshalTOML() (interface{}, error) {
 	enc.MinerThreads = c.MinerThreads
 	enc.ExtraData = c.ExtraData
 	enc.GasPrice = c.GasPrice
-	enc.EthashCacheDir = c.EthashCacheDir
-	enc.EthashCachesInMem = c.EthashCachesInMem
-	enc.EthashCachesOnDisk = c.EthashCachesOnDisk
-	enc.EthashDatasetDir = c.EthashDatasetDir
-	enc.EthashDatasetsInMem = c.EthashDatasetsInMem
-	enc.EthashDatasetsOnDisk = c.EthashDatasetsOnDisk
+	enc.EthashCacheDir = c.Ethash.CacheDir
+	enc.EthashCachesInMem = c.Ethash.CachesInMem
+	enc.EthashCachesOnDisk = c.Ethash.CachesOnDisk
+	enc.EthashDatasetDir = c.Ethash.DatasetDir
+	enc.EthashDatasetsInMem = c.Ethash.DatasetsInMem
+	enc.EthashDatasetsOnDisk = c.Ethash.DatasetsOnDisk
 	enc.TxPool = c.TxPool
 	enc.GPO = c.GPO
 	enc.EnablePreimageRecording = c.EnablePreimageRecording
 	enc.DocRoot = c.DocRoot
-	enc.PowFake = c.PowFake
-	enc.PowTest = c.PowTest
-	enc.PowShared = c.PowShared
+	enc.PowMode = c.Ethash.PowMode
 	return &enc, nil
 }
 
@@ -94,10 +91,8 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 		TxPool                  *core.TxPoolConfig
 		GPO                     *gasprice.Config
 		EnablePreimageRecording *bool
-		DocRoot                 *string `toml:"-"`
-		PowFake                 *bool   `toml:"-"`
-		PowTest                 *bool   `toml:"-"`
-		PowShared               *bool   `toml:"-"`
+		DocRoot                 *string      `toml:"-"`
+		PowMode                 *ethash.Mode `toml:"-"`
 	}
 	var dec Config
 	if err := unmarshal(&dec); err != nil {
@@ -140,22 +135,22 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 		c.GasPrice = dec.GasPrice
 	}
 	if dec.EthashCacheDir != nil {
-		c.EthashCacheDir = *dec.EthashCacheDir
+		c.Ethash.CacheDir = *dec.EthashCacheDir
 	}
 	if dec.EthashCachesInMem != nil {
-		c.EthashCachesInMem = *dec.EthashCachesInMem
+		c.Ethash.CachesInMem = *dec.EthashCachesInMem
 	}
 	if dec.EthashCachesOnDisk != nil {
-		c.EthashCachesOnDisk = *dec.EthashCachesOnDisk
+		c.Ethash.CachesOnDisk = *dec.EthashCachesOnDisk
 	}
 	if dec.EthashDatasetDir != nil {
-		c.EthashDatasetDir = *dec.EthashDatasetDir
+		c.Ethash.DatasetDir = *dec.EthashDatasetDir
 	}
 	if dec.EthashDatasetsInMem != nil {
-		c.EthashDatasetsInMem = *dec.EthashDatasetsInMem
+		c.Ethash.DatasetsInMem = *dec.EthashDatasetsInMem
 	}
 	if dec.EthashDatasetsOnDisk != nil {
-		c.EthashDatasetsOnDisk = *dec.EthashDatasetsOnDisk
+		c.Ethash.DatasetsOnDisk = *dec.EthashDatasetsOnDisk
 	}
 	if dec.TxPool != nil {
 		c.TxPool = *dec.TxPool
@@ -169,14 +164,8 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 	if dec.DocRoot != nil {
 		c.DocRoot = *dec.DocRoot
 	}
-	if dec.PowFake != nil {
-		c.PowFake = *dec.PowFake
-	}
-	if dec.PowTest != nil {
-		c.PowTest = *dec.PowTest
-	}
-	if dec.PowShared != nil {
-		c.PowShared = *dec.PowShared
+	if dec.PowMode != nil {
+		c.Ethash.PowMode = *dec.PowMode
 	}
 	return nil
 }
diff --git a/les/backend.go b/les/backend.go
index 333df920e..7180b81d7 100644
--- a/les/backend.go
+++ b/les/backend.go
@@ -98,7 +98,7 @@ func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
 		peers:            peers,
 		reqDist:          newRequestDistributor(peers, quitSync),
 		accountManager:   ctx.AccountManager,
-		engine:           eth.CreateConsensusEngine(ctx, config, chainConfig, chainDb),
+		engine:           eth.CreateConsensusEngine(ctx, &config.Ethash, chainConfig, chainDb),
 		shutdownChan:     make(chan bool),
 		networkId:        config.NetworkId,
 		bloomRequests:    make(chan chan *bloombits.Retrieval),