diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
index 0095edbdb4..7cd03d14e4 100644
--- a/accounts/abi/bind/backends/simulated.go
+++ b/accounts/abi/bind/backends/simulated.go
@@ -78,8 +78,11 @@ type SimulatedBackend struct {
 // and uses a simulated blockchain for testing purposes.
 // A simulated backend always uses chainID 1337.
 func NewSimulatedBackendWithDatabase(database ethdb.Database, alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
-	genesis := core.Genesis{Config: params.AllEthashProtocolChanges, GasLimit: gasLimit, Alloc: alloc}
-	genesis.MustCommit(database)
+	genesis := core.Genesis{
+		Config:   params.AllEthashProtocolChanges,
+		GasLimit: gasLimit,
+		Alloc:    alloc,
+	}
 	blockchain, _ := core.NewBlockChain(database, nil, &genesis, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 
 	backend := &SimulatedBackend{
diff --git a/consensus/clique/clique_test.go b/consensus/clique/clique_test.go
index 74d884a21b..f213bc8247 100644
--- a/consensus/clique/clique_test.go
+++ b/consensus/clique/clique_test.go
@@ -53,13 +53,12 @@ func TestReimportMirroredState(t *testing.T) {
 		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
 	copy(genspec.ExtraData[extraVanity:], addr[:])
-	genesis := genspec.MustCommit(db)
 
 	// Generate a batch of blocks, each properly signed
-	chain, _ := core.NewBlockChain(db, nil, genspec, nil, engine, vm.Config{}, nil, nil)
+	chain, _ := core.NewBlockChain(rawdb.NewMemoryDatabase(), nil, genspec, nil, engine, vm.Config{}, nil, nil)
 	defer chain.Stop()
 
-	blocks, _ := core.GenerateChain(params.AllCliqueProtocolChanges, genesis, engine, db, 3, func(i int, block *core.BlockGen) {
+	_, blocks, _ := core.GenerateChainWithGenesis(genspec, engine, 3, func(i int, block *core.BlockGen) {
 		// The chain maker doesn't have access to a chain, so the difficulty will be
 		// lets unset (nil). Set it here to the correct value.
 		block.SetDifficulty(diffInTurn)
@@ -88,8 +87,6 @@ func TestReimportMirroredState(t *testing.T) {
 	}
 	// Insert the first two blocks and make sure the chain is valid
 	db = rawdb.NewMemoryDatabase()
-	genspec.MustCommit(db)
-
 	chain, _ = core.NewBlockChain(db, nil, genspec, nil, engine, vm.Config{}, nil, nil)
 	defer chain.Stop()
 
diff --git a/consensus/clique/snapshot_test.go b/consensus/clique/snapshot_test.go
index a1e481abbf..4f9222d092 100644
--- a/consensus/clique/snapshot_test.go
+++ b/consensus/clique/snapshot_test.go
@@ -401,9 +401,6 @@ func TestClique(t *testing.T) {
 		for j, signer := range signers {
 			copy(genesis.ExtraData[extraVanity+j*common.AddressLength:], signer[:])
 		}
-		// Create a pristine blockchain with the genesis injected
-		db := rawdb.NewMemoryDatabase()
-		genesisBlock := genesis.MustCommit(db)
 
 		// Assemble a chain of headers from the cast votes
 		config := *params.TestChainConfig
@@ -412,10 +409,11 @@ func TestClique(t *testing.T) {
 			Epoch:  tt.epoch,
 		}
 		genesis.Config = &config
-		engine := New(config.Clique, db)
+
+		engine := New(config.Clique, rawdb.NewMemoryDatabase())
 		engine.fakeDiff = true
 
-		blocks, _ := core.GenerateChain(&config, genesisBlock, engine, db, len(tt.votes), func(j int, gen *core.BlockGen) {
+		_, blocks, _ := core.GenerateChainWithGenesis(genesis, engine, len(tt.votes), func(j int, gen *core.BlockGen) {
 			// Cast the vote contained in this block
 			gen.SetCoinbase(accounts.address(tt.votes[j].voted))
 			if tt.votes[j].auth {
@@ -451,7 +449,7 @@ func TestClique(t *testing.T) {
 			batches[len(batches)-1] = append(batches[len(batches)-1], block)
 		}
 		// Pass all the headers through clique and ensure tallying succeeds
-		chain, err := core.NewBlockChain(db, nil, genesis, nil, engine, vm.Config{}, nil, nil)
+		chain, err := core.NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 		if err != nil {
 			t.Errorf("test %d: failed to create test chain: %v", i, err)
 			continue
diff --git a/core/bench_test.go b/core/bench_test.go
index e448310e4d..f7cf014606 100644
--- a/core/bench_test.go
+++ b/core/bench_test.go
@@ -187,16 +187,15 @@ func benchInsertChain(b *testing.B, disk bool, gen func(int, *BlockGen)) {
 
 	// Generate a chain of b.N blocks using the supplied block
 	// generator function.
-	gspec := Genesis{
+	gspec := &Genesis{
 		Config: params.TestChainConfig,
 		Alloc:  GenesisAlloc{benchRootAddr: {Balance: benchRootFunds}},
 	}
-	genesis := gspec.MustCommit(db)
-	chain, _ := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, b.N, gen)
+	_, chain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), b.N, gen)
 
 	// Time the insertion of the new chain.
 	// State and blocks are stored in the same DB.
-	chainman, _ := NewBlockChain(db, nil, &gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	chainman, _ := NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer chainman.Stop()
 	b.ReportAllocs()
 	b.ResetTimer()
diff --git a/core/block_validator_test.go b/core/block_validator_test.go
index 815bc86552..3bdb20e7e1 100644
--- a/core/block_validator_test.go
+++ b/core/block_validator_test.go
@@ -39,17 +39,15 @@ import (
 func TestHeaderVerification(t *testing.T) {
 	// Create a simple chain to verify
 	var (
-		testdb    = rawdb.NewMemoryDatabase()
-		gspec     = &Genesis{Config: params.TestChainConfig}
-		genesis   = gspec.MustCommit(testdb)
-		blocks, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), testdb, 8, nil)
+		gspec        = &Genesis{Config: params.TestChainConfig}
+		_, blocks, _ = GenerateChainWithGenesis(gspec, ethash.NewFaker(), 8, nil)
 	)
 	headers := make([]*types.Header, len(blocks))
 	for i, block := range blocks {
 		headers[i] = block.Header()
 	}
 	// Run the header checker for blocks one-by-one, checking for both valid and invalid nonces
-	chain, _ := NewBlockChain(testdb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	chain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer chain.Stop()
 
 	for i := 0; i < len(blocks); i++ {
@@ -89,21 +87,21 @@ func TestHeaderVerificationForMergingEthash(t *testing.T) { testHeaderVerificati
 // Tests the verification for eth1/2 merging, including pre-merge and post-merge
 func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 	var (
-		testdb     = rawdb.NewMemoryDatabase()
+		gspec      *Genesis
 		preBlocks  []*types.Block
 		postBlocks []*types.Block
-		runEngine  consensus.Engine
-		genspec    *Genesis
+		engine     consensus.Engine
 		merger     = consensus.NewMerger(rawdb.NewMemoryDatabase())
 	)
 	if isClique {
 		var (
 			key, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 			addr   = crypto.PubkeyToAddress(key.PublicKey)
-			engine = clique.New(params.AllCliqueProtocolChanges.Clique, testdb)
+			config = *params.AllCliqueProtocolChanges
 		)
-		genspec = &Genesis{
-			Config:    params.AllCliqueProtocolChanges,
+		engine = beacon.New(clique.New(params.AllCliqueProtocolChanges.Clique, rawdb.NewMemoryDatabase()))
+		gspec = &Genesis{
+			Config:    &config,
 			ExtraData: make([]byte, 32+common.AddressLength+crypto.SignatureLength),
 			Alloc: map[common.Address]GenesisAccount{
 				addr: {Balance: big.NewInt(1)},
@@ -111,50 +109,44 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 			BaseFee:    big.NewInt(params.InitialBaseFee),
 			Difficulty: new(big.Int),
 		}
-		copy(genspec.ExtraData[32:], addr[:])
-		genesis := genspec.MustCommit(testdb)
+		copy(gspec.ExtraData[32:], addr[:])
 
-		genEngine := beacon.New(engine)
-		preBlocks, _ = GenerateChain(params.AllCliqueProtocolChanges, genesis, genEngine, testdb, 8, nil)
 		td := 0
-		for i, block := range preBlocks {
+		genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, 8, nil)
+		for i, block := range blocks {
 			header := block.Header()
 			if i > 0 {
-				header.ParentHash = preBlocks[i-1].Hash()
+				header.ParentHash = blocks[i-1].Hash()
 			}
 			header.Extra = make([]byte, 32+crypto.SignatureLength)
 			header.Difficulty = big.NewInt(2)
 
-			sig, _ := crypto.Sign(genEngine.SealHash(header).Bytes(), key)
+			sig, _ := crypto.Sign(engine.SealHash(header).Bytes(), key)
 			copy(header.Extra[len(header.Extra)-crypto.SignatureLength:], sig)
-			preBlocks[i] = block.WithSeal(header)
+			blocks[i] = block.WithSeal(header)
+
 			// calculate td
 			td += int(block.Difficulty().Uint64())
 		}
-		config := *params.AllCliqueProtocolChanges
-		config.TerminalTotalDifficulty = big.NewInt(int64(td))
-		postBlocks, _ = GenerateChain(&config, preBlocks[len(preBlocks)-1], genEngine, testdb, 8, nil)
-		runEngine = beacon.New(engine)
-		genspec.Config = &config
+		preBlocks = blocks
+		gspec.Config.TerminalTotalDifficulty = big.NewInt(int64(td))
+		postBlocks, _ = GenerateChain(gspec.Config, preBlocks[len(preBlocks)-1], engine, genDb, 8, nil)
 	} else {
-		genspec = &Genesis{Config: params.TestChainConfig}
-		genesis := genspec.MustCommit(testdb)
-		genEngine := beacon.New(ethash.NewFaker())
+		config := *params.TestChainConfig
+		gspec = &Genesis{Config: &config}
+		engine = beacon.New(ethash.NewFaker())
 
-		preBlocks, _ = GenerateChain(params.TestChainConfig, genesis, genEngine, testdb, 8, nil)
 		td := 0
+		genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, 8, nil)
 		for _, block := range preBlocks {
 			// calculate td
 			td += int(block.Difficulty().Uint64())
 		}
-		config := *params.TestChainConfig
-		config.TerminalTotalDifficulty = big.NewInt(int64(td))
-		postBlocks, _ = GenerateChain(params.TestChainConfig, preBlocks[len(preBlocks)-1], genEngine, testdb, 8, nil)
-
-		runEngine = beacon.New(ethash.NewFaker())
-		genspec.Config = &config
+		preBlocks = blocks
+		gspec.Config.TerminalTotalDifficulty = big.NewInt(int64(td))
+		postBlocks, _ = GenerateChain(gspec.Config, preBlocks[len(preBlocks)-1], engine, genDb, 8, nil)
 	}
-
+	// Assemble header batch
 	preHeaders := make([]*types.Header, len(preBlocks))
 	for i, block := range preBlocks {
 		preHeaders[i] = block.Header()
@@ -170,12 +162,12 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 		t.Logf("Log header after the merging %d: %v", block.NumberU64(), string(blob))
 	}
 	// Run the header checker for blocks one-by-one, checking for both valid and invalid nonces
-	chain, _ := NewBlockChain(testdb, nil, genspec, nil, runEngine, vm.Config{}, nil, nil)
+	chain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	defer chain.Stop()
 
 	// Verify the blocks before the merging
 	for i := 0; i < len(preBlocks); i++ {
-		_, results := runEngine.VerifyHeaders(chain, []*types.Header{preHeaders[i]}, []bool{true})
+		_, results := engine.VerifyHeaders(chain, []*types.Header{preHeaders[i]}, []bool{true})
 		// Wait for the verification result
 		select {
 		case result := <-results:
@@ -200,7 +192,7 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 
 	// Verify the blocks after the merging
 	for i := 0; i < len(postBlocks); i++ {
-		_, results := runEngine.VerifyHeaders(chain, []*types.Header{postHeaders[i]}, []bool{true})
+		_, results := engine.VerifyHeaders(chain, []*types.Header{postHeaders[i]}, []bool{true})
 		// Wait for the verification result
 		select {
 		case result := <-results:
@@ -232,7 +224,7 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 		headers = append(headers, block.Header())
 		seals = append(seals, true)
 	}
-	_, results := runEngine.VerifyHeaders(chain, headers, seals)
+	_, results := engine.VerifyHeaders(chain, headers, seals)
 	for i := 0; i < len(headers); i++ {
 		select {
 		case result := <-results:
@@ -259,10 +251,8 @@ func TestHeaderConcurrentVerification32(t *testing.T) { testHeaderConcurrentVeri
 func testHeaderConcurrentVerification(t *testing.T, threads int) {
 	// Create a simple chain to verify
 	var (
-		testdb    = rawdb.NewMemoryDatabase()
-		gspec     = &Genesis{Config: params.TestChainConfig}
-		genesis   = gspec.MustCommit(testdb)
-		blocks, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), testdb, 8, nil)
+		gspec        = &Genesis{Config: params.TestChainConfig}
+		_, blocks, _ = GenerateChainWithGenesis(gspec, ethash.NewFaker(), 8, nil)
 	)
 	headers := make([]*types.Header, len(blocks))
 	seals := make([]bool, len(blocks))
@@ -281,11 +271,11 @@ func testHeaderConcurrentVerification(t *testing.T, threads int) {
 		var results <-chan error
 
 		if valid {
-			chain, _ := NewBlockChain(testdb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+			chain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 			_, results = chain.engine.VerifyHeaders(chain, headers, seals)
 			chain.Stop()
 		} else {
-			chain, _ := NewBlockChain(testdb, nil, gspec, nil, ethash.NewFakeFailer(uint64(len(headers)-1)), vm.Config{}, nil, nil)
+			chain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFakeFailer(uint64(len(headers)-1)), vm.Config{}, nil, nil)
 			_, results = chain.engine.VerifyHeaders(chain, headers, seals)
 			chain.Stop()
 		}
@@ -331,10 +321,8 @@ func TestHeaderConcurrentAbortion32(t *testing.T) { testHeaderConcurrentAbortion
 func testHeaderConcurrentAbortion(t *testing.T, threads int) {
 	// Create a simple chain to verify
 	var (
-		testdb    = rawdb.NewMemoryDatabase()
-		gspec     = &Genesis{Config: params.TestChainConfig}
-		genesis   = gspec.MustCommit(testdb)
-		blocks, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), testdb, 1024, nil)
+		gspec        = &Genesis{Config: params.TestChainConfig}
+		_, blocks, _ = GenerateChainWithGenesis(gspec, ethash.NewFaker(), 1024, nil)
 	)
 	headers := make([]*types.Header, len(blocks))
 	seals := make([]bool, len(blocks))
@@ -348,7 +336,7 @@ func testHeaderConcurrentAbortion(t *testing.T, threads int) {
 	defer runtime.GOMAXPROCS(old)
 
 	// Start the verifications and immediately abort
-	chain, _ := NewBlockChain(testdb, nil, gspec, nil, ethash.NewFakeDelayer(time.Millisecond), vm.Config{}, nil, nil)
+	chain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFakeDelayer(time.Millisecond), vm.Config{}, nil, nil)
 	defer chain.Stop()
 
 	abort, results := chain.engine.VerifyHeaders(chain, headers, seals)
diff --git a/core/blockchain_repair_test.go b/core/blockchain_repair_test.go
index 04154158c9..6e61f89c3b 100644
--- a/core/blockchain_repair_test.go
+++ b/core/blockchain_repair_test.go
@@ -1768,9 +1768,8 @@ func testRepair(t *testing.T, tt *rewindTest, snapshots bool) {
 			BaseFee: big.NewInt(params.InitialBaseFee),
 			Config:  params.AllEthashProtocolChanges,
 		}
-		genesis = gspec.MustCommit(db)
-		engine  = ethash.NewFullFaker()
-		config  = &CacheConfig{
+		engine = ethash.NewFullFaker()
+		config = &CacheConfig{
 			TrieCleanLimit: 256,
 			TrieDirtyLimit: 256,
 			TrieTimeLimit:  5 * time.Minute,
@@ -1789,14 +1788,14 @@ func testRepair(t *testing.T, tt *rewindTest, snapshots bool) {
 	// If sidechain blocks are needed, make a light chain and import it
 	var sideblocks types.Blocks
 	if tt.sidechainBlocks > 0 {
-		sideblocks, _ = GenerateChain(params.TestChainConfig, genesis, engine, rawdb.NewMemoryDatabase(), tt.sidechainBlocks, func(i int, b *BlockGen) {
+		sideblocks, _ = GenerateChain(gspec.Config, gspec.ToBlock(), engine, rawdb.NewMemoryDatabase(), tt.sidechainBlocks, func(i int, b *BlockGen) {
 			b.SetCoinbase(common.Address{0x01})
 		})
 		if _, err := chain.InsertChain(sideblocks); err != nil {
 			t.Fatalf("Failed to import side chain: %v", err)
 		}
 	}
-	canonblocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, rawdb.NewMemoryDatabase(), tt.canonicalBlocks, func(i int, b *BlockGen) {
+	canonblocks, _ := GenerateChain(gspec.Config, gspec.ToBlock(), engine, rawdb.NewMemoryDatabase(), tt.canonicalBlocks, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{0x02})
 		b.SetDifficulty(big.NewInt(1000000))
 	})
@@ -1896,9 +1895,8 @@ func TestIssue23496(t *testing.T) {
 			Config:  params.TestChainConfig,
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(db)
-		engine  = ethash.NewFullFaker()
-		config  = &CacheConfig{
+		engine = ethash.NewFullFaker()
+		config = &CacheConfig{
 			TrieCleanLimit: 256,
 			TrieDirtyLimit: 256,
 			TrieTimeLimit:  5 * time.Minute,
@@ -1910,7 +1908,7 @@ func TestIssue23496(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Failed to create chain: %v", err)
 	}
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, rawdb.NewMemoryDatabase(), 4, func(i int, b *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 4, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{0x02})
 		b.SetDifficulty(big.NewInt(1000000))
 	})
diff --git a/core/blockchain_sethead_test.go b/core/blockchain_sethead_test.go
index c5df7949ef..1eb588d02f 100644
--- a/core/blockchain_sethead_test.go
+++ b/core/blockchain_sethead_test.go
@@ -1968,9 +1968,8 @@ func testSetHead(t *testing.T, tt *rewindTest, snapshots bool) {
 			BaseFee: big.NewInt(params.InitialBaseFee),
 			Config:  params.AllEthashProtocolChanges,
 		}
-		genesis = gspec.MustCommit(db)
-		engine  = ethash.NewFullFaker()
-		config  = &CacheConfig{
+		engine = ethash.NewFullFaker()
+		config = &CacheConfig{
 			TrieCleanLimit: 256,
 			TrieDirtyLimit: 256,
 			TrieTimeLimit:  5 * time.Minute,
@@ -1988,14 +1987,14 @@ func testSetHead(t *testing.T, tt *rewindTest, snapshots bool) {
 	// If sidechain blocks are needed, make a light chain and import it
 	var sideblocks types.Blocks
 	if tt.sidechainBlocks > 0 {
-		sideblocks, _ = GenerateChain(params.TestChainConfig, genesis, engine, rawdb.NewMemoryDatabase(), tt.sidechainBlocks, func(i int, b *BlockGen) {
+		sideblocks, _ = GenerateChain(gspec.Config, gspec.ToBlock(), engine, rawdb.NewMemoryDatabase(), tt.sidechainBlocks, func(i int, b *BlockGen) {
 			b.SetCoinbase(common.Address{0x01})
 		})
 		if _, err := chain.InsertChain(sideblocks); err != nil {
 			t.Fatalf("Failed to import side chain: %v", err)
 		}
 	}
-	canonblocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, rawdb.NewMemoryDatabase(), tt.canonicalBlocks, func(i int, b *BlockGen) {
+	canonblocks, _ := GenerateChain(gspec.Config, gspec.ToBlock(), engine, rawdb.NewMemoryDatabase(), tt.canonicalBlocks, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{0x02})
 		b.SetDifficulty(big.NewInt(1000000))
 	})
diff --git a/core/blockchain_snapshot_test.go b/core/blockchain_snapshot_test.go
index 01a88d7a3c..1b38ad51e9 100644
--- a/core/blockchain_snapshot_test.go
+++ b/core/blockchain_snapshot_test.go
@@ -52,7 +52,7 @@ type snapshotTestBasic struct {
 	// share fields, set in runtime
 	datadir string
 	db      ethdb.Database
-	gendb   ethdb.Database
+	genDb   ethdb.Database
 	engine  consensus.Engine
 	gspec   *Genesis
 }
@@ -71,9 +71,7 @@ func (basic *snapshotTestBasic) prepare(t *testing.T) (*BlockChain, []*types.Blo
 			BaseFee: big.NewInt(params.InitialBaseFee),
 			Config:  params.AllEthashProtocolChanges,
 		}
-		genesis = gspec.MustCommit(db)
-		engine  = ethash.NewFullFaker()
-		gendb   = rawdb.NewMemoryDatabase()
+		engine = ethash.NewFullFaker()
 
 		// Snapshot is enabled, the first snapshot is created from the Genesis.
 		// The snapshot memory allowance is 256MB, it means no snapshot flush
@@ -84,7 +82,7 @@ func (basic *snapshotTestBasic) prepare(t *testing.T) (*BlockChain, []*types.Blo
 	if err != nil {
 		t.Fatalf("Failed to create chain: %v", err)
 	}
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, gendb, basic.chainBlocks, func(i int, b *BlockGen) {})
+	genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, basic.chainBlocks, func(i int, b *BlockGen) {})
 
 	// Insert the blocks with configured settings.
 	var breakpoints []uint64
@@ -121,7 +119,7 @@ func (basic *snapshotTestBasic) prepare(t *testing.T) (*BlockChain, []*types.Blo
 	// Set runtime fields
 	basic.datadir = datadir
 	basic.db = db
-	basic.gendb = gendb
+	basic.genDb = genDb
 	basic.engine = engine
 	basic.gspec = gspec
 	return chain, blocks
@@ -207,7 +205,7 @@ func (basic *snapshotTestBasic) dump() string {
 
 func (basic *snapshotTestBasic) teardown() {
 	basic.db.Close()
-	basic.gendb.Close()
+	basic.genDb.Close()
 	os.RemoveAll(basic.datadir)
 }
 
@@ -294,7 +292,7 @@ func (snaptest *gappedSnapshotTest) test(t *testing.T) {
 
 	// Insert blocks without enabling snapshot if gapping is required.
 	chain.Stop()
-	gappedBlocks, _ := GenerateChain(params.TestChainConfig, blocks[len(blocks)-1], snaptest.engine, snaptest.gendb, snaptest.gapped, func(i int, b *BlockGen) {})
+	gappedBlocks, _ := GenerateChain(params.TestChainConfig, blocks[len(blocks)-1], snaptest.engine, snaptest.genDb, snaptest.gapped, func(i int, b *BlockGen) {})
 
 	// Insert a few more blocks without enabling snapshot
 	var cacheConfig = &CacheConfig{
@@ -378,7 +376,7 @@ func (snaptest *wipeCrashSnapshotTest) test(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Failed to recreate chain: %v", err)
 	}
-	newBlocks, _ := GenerateChain(params.TestChainConfig, blocks[len(blocks)-1], snaptest.engine, snaptest.gendb, snaptest.newBlocks, func(i int, b *BlockGen) {})
+	newBlocks, _ := GenerateChain(params.TestChainConfig, blocks[len(blocks)-1], snaptest.engine, snaptest.genDb, snaptest.newBlocks, func(i int, b *BlockGen) {})
 	newchain.InsertChain(newBlocks)
 	newchain.Stop()
 
@@ -395,7 +393,6 @@ func (snaptest *wipeCrashSnapshotTest) test(t *testing.T) {
 		t.Fatalf("Failed to recreate chain: %v", err)
 	}
 	// Simulate the blockchain crash.
-
 	newchain, err = NewBlockChain(snaptest.db, nil, snaptest.gspec, nil, snaptest.engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("Failed to recreate chain: %v", err)
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index 713ac2809a..c17a81048f 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -50,33 +50,32 @@ var (
 
 // newCanonical creates a chain database, and injects a deterministic canonical
 // chain. Depending on the full flag, if creates either a full block chain or a
-// header only chain.
-func newCanonical(engine consensus.Engine, n int, full bool) (ethdb.Database, *BlockChain, error) {
+// header only chain. The database and genesis specification for block generation
+// are also returned in case more test blocks are needed later.
+func newCanonical(engine consensus.Engine, n int, full bool) (ethdb.Database, *Genesis, *BlockChain, error) {
 	var (
-		db    = rawdb.NewMemoryDatabase()
-		gspec = &Genesis{
+		genesis = &Genesis{
 			BaseFee: big.NewInt(params.InitialBaseFee),
 			Config:  params.AllEthashProtocolChanges,
 		}
-		genesis = gspec.MustCommit(db)
 	)
-
 	// Initialize a fresh chain with only a genesis block
-	blockchain, _ := NewBlockChain(db, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	blockchain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
+
 	// Create and inject the requested chain
 	if n == 0 {
-		return db, blockchain, nil
+		return rawdb.NewMemoryDatabase(), genesis, blockchain, nil
 	}
 	if full {
 		// Full block-chain requested
-		blocks := makeBlockChain(genesis, n, engine, db, canonicalSeed)
+		genDb, blocks := makeBlockChainWithGenesis(genesis, n, engine, canonicalSeed)
 		_, err := blockchain.InsertChain(blocks)
-		return db, blockchain, err
+		return genDb, genesis, blockchain, err
 	}
 	// Header-only chain requested
-	headers := makeHeaderChain(genesis.Header(), n, engine, db, canonicalSeed)
+	genDb, headers := makeHeaderChainWithGenesis(genesis, n, engine, canonicalSeed)
 	_, err := blockchain.InsertHeaderChain(headers, 1)
-	return db, blockchain, err
+	return genDb, genesis, blockchain, err
 }
 
 func newGwei(n int64) *big.Int {
@@ -86,7 +85,7 @@ func newGwei(n int64) *big.Int {
 // Test fork of length N starting from block i
 func testFork(t *testing.T, blockchain *BlockChain, i, n int, full bool, comparator func(td1, td2 *big.Int)) {
 	// Copy old chain up to #i into a new db
-	db, blockchain2, err := newCanonical(ethash.NewFaker(), i, full)
+	genDb, _, blockchain2, err := newCanonical(ethash.NewFaker(), i, full)
 	if err != nil {
 		t.Fatal("could not make new canonical in testFork", err)
 	}
@@ -110,12 +109,12 @@ func testFork(t *testing.T, blockchain *BlockChain, i, n int, full bool, compara
 		headerChainB []*types.Header
 	)
 	if full {
-		blockChainB = makeBlockChain(blockchain2.CurrentBlock(), n, ethash.NewFaker(), db, forkSeed)
+		blockChainB = makeBlockChain(blockchain2.chainConfig, blockchain2.CurrentBlock(), n, ethash.NewFaker(), genDb, forkSeed)
 		if _, err := blockchain2.InsertChain(blockChainB); err != nil {
 			t.Fatalf("failed to insert forking chain: %v", err)
 		}
 	} else {
-		headerChainB = makeHeaderChain(blockchain2.CurrentHeader(), n, ethash.NewFaker(), db, forkSeed)
+		headerChainB = makeHeaderChain(blockchain2.chainConfig, blockchain2.CurrentHeader(), n, ethash.NewFaker(), genDb, forkSeed)
 		if _, err := blockchain2.InsertHeaderChain(headerChainB, 1); err != nil {
 			t.Fatalf("failed to insert forking chain: %v", err)
 		}
@@ -201,13 +200,13 @@ func testHeaderChainImport(chain []*types.Header, blockchain *BlockChain) error
 }
 
 func TestLastBlock(t *testing.T) {
-	_, blockchain, err := newCanonical(ethash.NewFaker(), 0, true)
+	genDb, _, blockchain, err := newCanonical(ethash.NewFaker(), 0, true)
 	if err != nil {
 		t.Fatalf("failed to create pristine chain: %v", err)
 	}
 	defer blockchain.Stop()
 
-	blocks := makeBlockChain(blockchain.CurrentBlock(), 1, ethash.NewFullFaker(), blockchain.db, 0)
+	blocks := makeBlockChain(blockchain.chainConfig, blockchain.CurrentBlock(), 1, ethash.NewFullFaker(), genDb, 0)
 	if _, err := blockchain.InsertChain(blocks); err != nil {
 		t.Fatalf("Failed to insert block: %v", err)
 	}
@@ -220,7 +219,7 @@ func TestLastBlock(t *testing.T) {
 // The chain is reorged to whatever specified.
 func testInsertAfterMerge(t *testing.T, blockchain *BlockChain, i, n int, full bool) {
 	// Copy old chain up to #i into a new db
-	db, blockchain2, err := newCanonical(ethash.NewFaker(), i, full)
+	genDb, _, blockchain2, err := newCanonical(ethash.NewFaker(), i, full)
 	if err != nil {
 		t.Fatal("could not make new canonical in testFork", err)
 	}
@@ -241,7 +240,7 @@ func testInsertAfterMerge(t *testing.T, blockchain *BlockChain, i, n int, full b
 
 	// Extend the newly created chain
 	if full {
-		blockChainB := makeBlockChain(blockchain2.CurrentBlock(), n, ethash.NewFaker(), db, forkSeed)
+		blockChainB := makeBlockChain(blockchain2.chainConfig, blockchain2.CurrentBlock(), n, ethash.NewFaker(), genDb, forkSeed)
 		if _, err := blockchain2.InsertChain(blockChainB); err != nil {
 			t.Fatalf("failed to insert forking chain: %v", err)
 		}
@@ -252,7 +251,7 @@ func testInsertAfterMerge(t *testing.T, blockchain *BlockChain, i, n int, full b
 			t.Fatalf("failed to reorg to the given chain")
 		}
 	} else {
-		headerChainB := makeHeaderChain(blockchain2.CurrentHeader(), n, ethash.NewFaker(), db, forkSeed)
+		headerChainB := makeHeaderChain(blockchain2.chainConfig, blockchain2.CurrentHeader(), n, ethash.NewFaker(), genDb, forkSeed)
 		if _, err := blockchain2.InsertHeaderChain(headerChainB, 1); err != nil {
 			t.Fatalf("failed to insert forking chain: %v", err)
 		}
@@ -274,7 +273,7 @@ func testExtendCanonical(t *testing.T, full bool) {
 	length := 5
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -302,7 +301,7 @@ func testExtendCanonicalAfterMerge(t *testing.T, full bool) {
 	length := 5
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -321,7 +320,7 @@ func testShorterFork(t *testing.T, full bool) {
 	length := 10
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -351,7 +350,7 @@ func testShorterForkAfterMerge(t *testing.T, full bool) {
 	length := 10
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -374,7 +373,7 @@ func testLongerFork(t *testing.T, full bool) {
 	length := 10
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -397,7 +396,7 @@ func testLongerForkAfterMerge(t *testing.T, full bool) {
 	length := 10
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -420,7 +419,7 @@ func testEqualFork(t *testing.T, full bool) {
 	length := 10
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -450,7 +449,7 @@ func testEqualForkAfterMerge(t *testing.T, full bool) {
 	length := 10
 
 	// Make first chain starting from genesis
-	_, processor, err := newCanonical(ethash.NewFaker(), length, full)
+	_, _, processor, err := newCanonical(ethash.NewFaker(), length, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -470,7 +469,7 @@ func TestBrokenBlockChain(t *testing.T)  { testBrokenChain(t, true) }
 
 func testBrokenChain(t *testing.T, full bool) {
 	// Make chain starting from genesis
-	db, blockchain, err := newCanonical(ethash.NewFaker(), 10, full)
+	genDb, _, blockchain, err := newCanonical(ethash.NewFaker(), 10, full)
 	if err != nil {
 		t.Fatalf("failed to make new canonical chain: %v", err)
 	}
@@ -478,12 +477,12 @@ func testBrokenChain(t *testing.T, full bool) {
 
 	// Create a forked chain, and try to insert with a missing link
 	if full {
-		chain := makeBlockChain(blockchain.CurrentBlock(), 5, ethash.NewFaker(), db, forkSeed)[1:]
+		chain := makeBlockChain(blockchain.chainConfig, blockchain.CurrentBlock(), 5, ethash.NewFaker(), genDb, forkSeed)[1:]
 		if err := testBlockChainImport(chain, blockchain); err == nil {
 			t.Errorf("broken block chain not reported")
 		}
 	} else {
-		chain := makeHeaderChain(blockchain.CurrentHeader(), 5, ethash.NewFaker(), db, forkSeed)[1:]
+		chain := makeHeaderChain(blockchain.chainConfig, blockchain.CurrentHeader(), 5, ethash.NewFaker(), genDb, forkSeed)[1:]
 		if err := testHeaderChainImport(chain, blockchain); err == nil {
 			t.Errorf("broken header chain not reported")
 		}
@@ -521,17 +520,17 @@ func testReorgShort(t *testing.T, full bool) {
 
 func testReorg(t *testing.T, first, second []int64, td int64, full bool) {
 	// Create a pristine chain and database
-	db, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
+	genDb, _, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
 	if err != nil {
 		t.Fatalf("failed to create pristine chain: %v", err)
 	}
 	defer blockchain.Stop()
 
 	// Insert an easy and a difficult chain afterwards
-	easyBlocks, _ := GenerateChain(params.TestChainConfig, blockchain.CurrentBlock(), ethash.NewFaker(), db, len(first), func(i int, b *BlockGen) {
+	easyBlocks, _ := GenerateChain(params.TestChainConfig, blockchain.CurrentBlock(), ethash.NewFaker(), genDb, len(first), func(i int, b *BlockGen) {
 		b.OffsetTime(first[i])
 	})
-	diffBlocks, _ := GenerateChain(params.TestChainConfig, blockchain.CurrentBlock(), ethash.NewFaker(), db, len(second), func(i int, b *BlockGen) {
+	diffBlocks, _ := GenerateChain(params.TestChainConfig, blockchain.CurrentBlock(), ethash.NewFaker(), genDb, len(second), func(i int, b *BlockGen) {
 		b.OffsetTime(second[i])
 	})
 	if full {
@@ -594,7 +593,7 @@ func TestBadBlockHashes(t *testing.T)  { testBadHashes(t, true) }
 
 func testBadHashes(t *testing.T, full bool) {
 	// Create a pristine chain and database
-	db, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
+	genDb, _, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
 	if err != nil {
 		t.Fatalf("failed to create pristine chain: %v", err)
 	}
@@ -602,14 +601,14 @@ func testBadHashes(t *testing.T, full bool) {
 
 	// Create a chain, ban a hash and try to import
 	if full {
-		blocks := makeBlockChain(blockchain.CurrentBlock(), 3, ethash.NewFaker(), db, 10)
+		blocks := makeBlockChain(blockchain.chainConfig, blockchain.CurrentBlock(), 3, ethash.NewFaker(), genDb, 10)
 
 		BadHashes[blocks[2].Header().Hash()] = true
 		defer func() { delete(BadHashes, blocks[2].Header().Hash()) }()
 
 		_, err = blockchain.InsertChain(blocks)
 	} else {
-		headers := makeHeaderChain(blockchain.CurrentHeader(), 3, ethash.NewFaker(), db, 10)
+		headers := makeHeaderChain(blockchain.chainConfig, blockchain.CurrentHeader(), 3, ethash.NewFaker(), genDb, 10)
 
 		BadHashes[headers[2].Hash()] = true
 		defer func() { delete(BadHashes, headers[2].Hash()) }()
@@ -628,13 +627,13 @@ func TestReorgBadBlockHashes(t *testing.T)  { testReorgBadHashes(t, true) }
 
 func testReorgBadHashes(t *testing.T, full bool) {
 	// Create a pristine chain and database
-	db, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
+	genDb, gspec, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
 	if err != nil {
 		t.Fatalf("failed to create pristine chain: %v", err)
 	}
 	// Create a chain, import and ban afterwards
-	headers := makeHeaderChain(blockchain.CurrentHeader(), 4, ethash.NewFaker(), db, 10)
-	blocks := makeBlockChain(blockchain.CurrentBlock(), 4, ethash.NewFaker(), db, 10)
+	headers := makeHeaderChain(blockchain.chainConfig, blockchain.CurrentHeader(), 4, ethash.NewFaker(), genDb, 10)
+	blocks := makeBlockChain(blockchain.chainConfig, blockchain.CurrentBlock(), 4, ethash.NewFaker(), genDb, 10)
 
 	if full {
 		if _, err = blockchain.InsertChain(blocks); err != nil {
@@ -658,10 +657,6 @@ func testReorgBadHashes(t *testing.T, full bool) {
 	blockchain.Stop()
 
 	// Create a new BlockChain and check that it rolled back the state.
-	gspec := &Genesis{
-		BaseFee: big.NewInt(params.InitialBaseFee),
-		Config:  params.AllEthashProtocolChanges,
-	}
 	ncm, err := NewBlockChain(blockchain.db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create new chain manager: %v", err)
@@ -688,7 +683,7 @@ func TestBlocksInsertNonceError(t *testing.T)  { testInsertNonceError(t, true) }
 func testInsertNonceError(t *testing.T, full bool) {
 	for i := 1; i < 25 && !t.Failed(); i++ {
 		// Create a pristine chain and database
-		db, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
+		genDb, _, blockchain, err := newCanonical(ethash.NewFaker(), 0, full)
 		if err != nil {
 			t.Fatalf("failed to create pristine chain: %v", err)
 		}
@@ -701,7 +696,7 @@ func testInsertNonceError(t *testing.T, full bool) {
 			failNum uint64
 		)
 		if full {
-			blocks := makeBlockChain(blockchain.CurrentBlock(), i, ethash.NewFaker(), db, 0)
+			blocks := makeBlockChain(blockchain.chainConfig, blockchain.CurrentBlock(), i, ethash.NewFaker(), genDb, 0)
 
 			failAt = rand.Int() % len(blocks)
 			failNum = blocks[failAt].NumberU64()
@@ -709,7 +704,7 @@ func testInsertNonceError(t *testing.T, full bool) {
 			blockchain.engine = ethash.NewFakeFailer(failNum)
 			failRes, err = blockchain.InsertChain(blocks)
 		} else {
-			headers := makeHeaderChain(blockchain.CurrentHeader(), i, ethash.NewFaker(), db, 0)
+			headers := makeHeaderChain(blockchain.chainConfig, blockchain.CurrentHeader(), i, ethash.NewFaker(), genDb, 0)
 
 			failAt = rand.Int() % len(headers)
 			failNum = headers[failAt].Number.Uint64()
@@ -742,7 +737,6 @@ func testInsertNonceError(t *testing.T, full bool) {
 func TestFastVsFullChains(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb   = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(1000000000000000)
@@ -751,10 +745,9 @@ func TestFastVsFullChains(t *testing.T) {
 			Alloc:   GenesisAlloc{address: {Balance: funds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(gendb)
-		signer  = types.LatestSigner(gspec.Config)
+		signer = types.LatestSigner(gspec.Config)
 	)
-	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, 1024, func(i int, block *BlockGen) {
+	_, blocks, receipts := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 1024, func(i int, block *BlockGen) {
 		block.SetCoinbase(common.Address{0x00})
 
 		// If the block number is multiple of 3, send a few bonus transactions to the miner
@@ -774,7 +767,6 @@ func TestFastVsFullChains(t *testing.T) {
 	})
 	// Import the chain as an archive node for the comparison baseline
 	archiveDb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(archiveDb)
 	archive, _ := NewBlockChain(archiveDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer archive.Stop()
 
@@ -783,7 +775,6 @@ func TestFastVsFullChains(t *testing.T) {
 	}
 	// Fast import the chain as a non-archive node to test
 	fastDb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(fastDb)
 	fast, _ := NewBlockChain(fastDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer fast.Stop()
 
@@ -798,13 +789,11 @@ func TestFastVsFullChains(t *testing.T) {
 		t.Fatalf("failed to insert receipt %d: %v", n, err)
 	}
 	// Freezer style fast import the chain.
-	frdir := t.TempDir()
-	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), frdir, "", false)
+	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), t.TempDir(), "", false)
 	if err != nil {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
 	defer ancientDb.Close()
-	gspec.MustCommit(ancientDb)
 	ancient, _ := NewBlockChain(ancientDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer ancient.Stop()
 
@@ -875,7 +864,6 @@ func TestFastVsFullChains(t *testing.T) {
 func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb   = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(1000000000000000)
@@ -884,19 +872,16 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 			Alloc:   GenesisAlloc{address: {Balance: funds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(gendb)
 	)
 	height := uint64(1024)
-	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, int(height), nil)
+	_, blocks, receipts := GenerateChainWithGenesis(gspec, ethash.NewFaker(), int(height), nil)
 
 	// makeDb creates a db instance for testing.
 	makeDb := func() ethdb.Database {
-		dir := t.TempDir()
-		db, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), dir, "", false)
+		db, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), t.TempDir(), "", false)
 		if err != nil {
 			t.Fatalf("failed to create temp freezer db: %v", err)
 		}
-		gspec.MustCommit(db)
 		return db
 	}
 	// Configure a subchain to roll back
@@ -995,7 +980,6 @@ func TestChainTxReorgs(t *testing.T) {
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
 		addr2   = crypto.PubkeyToAddress(key2.PublicKey)
 		addr3   = crypto.PubkeyToAddress(key3.PublicKey)
-		db      = rawdb.NewMemoryDatabase()
 		gspec   = &Genesis{
 			Config:   params.TestChainConfig,
 			GasLimit: 3141592,
@@ -1005,8 +989,7 @@ func TestChainTxReorgs(t *testing.T) {
 				addr3: {Balance: big.NewInt(1000000000000000)},
 			},
 		}
-		genesis = gspec.MustCommit(db)
-		signer  = types.LatestSigner(gspec.Config)
+		signer = types.LatestSigner(gspec.Config)
 	)
 
 	// Create two transactions shared between the chains:
@@ -1026,7 +1009,7 @@ func TestChainTxReorgs(t *testing.T) {
 	//  - futureAdd: transaction added after the reorg has already finished
 	var pastAdd, freshAdd, futureAdd *types.Transaction
 
-	chain, _ := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 3, func(i int, gen *BlockGen) {
+	_, chain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 3, func(i int, gen *BlockGen) {
 		switch i {
 		case 0:
 			pastDrop, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr2, big.NewInt(1000), params.TxGas, gen.header.BaseFee, nil), signer, key2)
@@ -1044,6 +1027,7 @@ func TestChainTxReorgs(t *testing.T) {
 		}
 	})
 	// Import the chain. This runs all block validation rules.
+	db := rawdb.NewMemoryDatabase()
 	blockchain, _ := NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	if i, err := blockchain.InsertChain(chain); err != nil {
 		t.Fatalf("failed to insert original chain[%d]: %v", i, err)
@@ -1051,7 +1035,7 @@ func TestChainTxReorgs(t *testing.T) {
 	defer blockchain.Stop()
 
 	// overwrite the old chain
-	chain, _ = GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 5, func(i int, gen *BlockGen) {
+	_, chain, _ = GenerateChainWithGenesis(gspec, ethash.NewFaker(), 5, func(i int, gen *BlockGen) {
 		switch i {
 		case 0:
 			pastAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), params.TxGas, gen.header.BaseFee, nil), signer, key3)
@@ -1106,20 +1090,19 @@ func TestLogReorgs(t *testing.T) {
 	var (
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
-		db      = rawdb.NewMemoryDatabase()
+
 		// this code generates a log
-		code    = common.Hex2Bytes("60606040525b7f24ec1d3ff24c2f6ff210738839dbc339cd45a5294d85c79361016243157aae7b60405180905060405180910390a15b600a8060416000396000f360606040526008565b00")
-		gspec   = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{addr1: {Balance: big.NewInt(10000000000000000)}}}
-		genesis = gspec.MustCommit(db)
-		signer  = types.LatestSigner(gspec.Config)
+		code   = common.Hex2Bytes("60606040525b7f24ec1d3ff24c2f6ff210738839dbc339cd45a5294d85c79361016243157aae7b60405180905060405180910390a15b600a8060416000396000f360606040526008565b00")
+		gspec  = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{addr1: {Balance: big.NewInt(10000000000000000)}}}
+		signer = types.LatestSigner(gspec.Config)
 	)
 
-	blockchain, _ := NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	blockchain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer blockchain.Stop()
 
 	rmLogsCh := make(chan RemovedLogsEvent)
 	blockchain.SubscribeRemovedLogsEvent(rmLogsCh)
-	chain, _ := GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 2, func(i int, gen *BlockGen) {
+	_, chain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 2, func(i int, gen *BlockGen) {
 		if i == 1 {
 			tx, err := types.SignTx(types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), 1000000, gen.header.BaseFee, code), signer, key1)
 			if err != nil {
@@ -1132,7 +1115,7 @@ func TestLogReorgs(t *testing.T) {
 		t.Fatalf("failed to insert chain: %v", err)
 	}
 
-	chain, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 3, func(i int, gen *BlockGen) {})
+	_, chain, _ = GenerateChainWithGenesis(gspec, ethash.NewFaker(), 3, func(i int, gen *BlockGen) {})
 	done := make(chan struct{})
 	go func() {
 		ev := <-rmLogsCh
@@ -1162,14 +1145,11 @@ func TestLogRebirth(t *testing.T) {
 	var (
 		key1, _       = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1         = crypto.PubkeyToAddress(key1.PublicKey)
-		db            = rawdb.NewMemoryDatabase()
 		gspec         = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{addr1: {Balance: big.NewInt(10000000000000000)}}}
-		genesis       = gspec.MustCommit(db)
 		signer        = types.LatestSigner(gspec.Config)
 		engine        = ethash.NewFaker()
-		blockchain, _ = NewBlockChain(db, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+		blockchain, _ = NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	)
-
 	defer blockchain.Stop()
 
 	// The event channels.
@@ -1179,7 +1159,7 @@ func TestLogRebirth(t *testing.T) {
 	blockchain.SubscribeRemovedLogsEvent(rmLogsCh)
 
 	// This chain contains a single log.
-	chain, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2, func(i int, gen *BlockGen) {
+	genDb, chain, _ := GenerateChainWithGenesis(gspec, engine, 2, func(i int, gen *BlockGen) {
 		if i == 1 {
 			tx, err := types.SignTx(types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), 1000000, gen.header.BaseFee, logCode), signer, key1)
 			if err != nil {
@@ -1195,7 +1175,7 @@ func TestLogRebirth(t *testing.T) {
 
 	// Generate long reorg chain containing another log. Inserting the
 	// chain removes one log and adds one.
-	forkChain, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2, func(i int, gen *BlockGen) {
+	_, forkChain, _ := GenerateChainWithGenesis(gspec, engine, 2, func(i int, gen *BlockGen) {
 		if i == 1 {
 			tx, err := types.SignTx(types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), 1000000, gen.header.BaseFee, logCode), signer, key1)
 			if err != nil {
@@ -1213,7 +1193,7 @@ func TestLogRebirth(t *testing.T) {
 	// This chain segment is rooted in the original chain, but doesn't contain any logs.
 	// When inserting it, the canonical chain switches away from forkChain and re-emits
 	// the log event for the old chain, as well as a RemovedLogsEvent for forkChain.
-	newBlocks, _ := GenerateChain(params.TestChainConfig, chain[len(chain)-1], engine, db, 1, func(i int, gen *BlockGen) {})
+	newBlocks, _ := GenerateChain(gspec.Config, chain[len(chain)-1], engine, genDb, 1, func(i int, gen *BlockGen) {})
 	if _, err := blockchain.InsertChain(newBlocks); err != nil {
 		t.Fatalf("failed to insert forked chain: %v", err)
 	}
@@ -1226,13 +1206,10 @@ func TestSideLogRebirth(t *testing.T) {
 	var (
 		key1, _       = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1         = crypto.PubkeyToAddress(key1.PublicKey)
-		db            = rawdb.NewMemoryDatabase()
 		gspec         = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{addr1: {Balance: big.NewInt(10000000000000000)}}}
-		genesis       = gspec.MustCommit(db)
 		signer        = types.LatestSigner(gspec.Config)
-		blockchain, _ = NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+		blockchain, _ = NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	)
-
 	defer blockchain.Stop()
 
 	newLogCh := make(chan []*types.Log, 10)
@@ -1240,7 +1217,7 @@ func TestSideLogRebirth(t *testing.T) {
 	blockchain.SubscribeLogsEvent(newLogCh)
 	blockchain.SubscribeRemovedLogsEvent(rmLogsCh)
 
-	chain, _ := GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 2, func(i int, gen *BlockGen) {
+	_, chain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 2, func(i int, gen *BlockGen) {
 		if i == 1 {
 			gen.OffsetTime(-9) // higher block difficulty
 		}
@@ -1251,7 +1228,7 @@ func TestSideLogRebirth(t *testing.T) {
 	checkLogEvents(t, newLogCh, rmLogsCh, 0, 0)
 
 	// Generate side chain with lower difficulty
-	sideChain, _ := GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 2, func(i int, gen *BlockGen) {
+	genDb, sideChain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 2, func(i int, gen *BlockGen) {
 		if i == 1 {
 			tx, err := types.SignTx(types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), 1000000, gen.header.BaseFee, logCode), signer, key1)
 			if err != nil {
@@ -1266,7 +1243,7 @@ func TestSideLogRebirth(t *testing.T) {
 	checkLogEvents(t, newLogCh, rmLogsCh, 0, 0)
 
 	// Generate a new block based on side chain.
-	newBlocks, _ := GenerateChain(params.TestChainConfig, sideChain[len(sideChain)-1], ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+	newBlocks, _ := GenerateChain(gspec.Config, sideChain[len(sideChain)-1], ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 	if _, err := blockchain.InsertChain(newBlocks); err != nil {
 		t.Fatalf("failed to insert forked chain: %v", err)
 	}
@@ -1293,26 +1270,23 @@ func checkLogEvents(t *testing.T, logsCh <-chan []*types.Log, rmLogsCh <-chan Re
 
 func TestReorgSideEvent(t *testing.T) {
 	var (
-		db      = rawdb.NewMemoryDatabase()
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
 		gspec   = &Genesis{
 			Config: params.TestChainConfig,
 			Alloc:  GenesisAlloc{addr1: {Balance: big.NewInt(10000000000000000)}},
 		}
-		genesis = gspec.MustCommit(db)
-		signer  = types.LatestSigner(gspec.Config)
+		signer = types.LatestSigner(gspec.Config)
 	)
-
-	blockchain, _ := NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	blockchain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer blockchain.Stop()
 
-	chain, _ := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 3, func(i int, gen *BlockGen) {})
+	_, chain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 3, func(i int, gen *BlockGen) {})
 	if _, err := blockchain.InsertChain(chain); err != nil {
 		t.Fatalf("failed to insert chain: %v", err)
 	}
 
-	replacementBlocks, _ := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 4, func(i int, gen *BlockGen) {
+	_, replacementBlocks, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 4, func(i int, gen *BlockGen) {
 		tx, err := types.SignTx(types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), 1000000, gen.header.BaseFee, nil), signer, key1)
 		if i == 2 {
 			gen.OffsetTime(-9)
@@ -1375,13 +1349,13 @@ done:
 
 // Tests if the canonical block can be fetched from the database during chain insertion.
 func TestCanonicalBlockRetrieval(t *testing.T) {
-	_, blockchain, err := newCanonical(ethash.NewFaker(), 0, true)
+	_, gspec, blockchain, err := newCanonical(ethash.NewFaker(), 0, true)
 	if err != nil {
 		t.Fatalf("failed to create pristine chain: %v", err)
 	}
 	defer blockchain.Stop()
 
-	chain, _ := GenerateChain(blockchain.chainConfig, blockchain.genesisBlock, ethash.NewFaker(), blockchain.db, 10, func(i int, gen *BlockGen) {})
+	_, chain, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 10, func(i int, gen *BlockGen) {})
 
 	var pend sync.WaitGroup
 	pend.Add(len(chain))
@@ -1423,22 +1397,21 @@ func TestCanonicalBlockRetrieval(t *testing.T) {
 func TestEIP155Transition(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		db         = rawdb.NewMemoryDatabase()
 		key, _     = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address    = crypto.PubkeyToAddress(key.PublicKey)
 		funds      = big.NewInt(1000000000)
 		deleteAddr = common.Address{1}
 		gspec      = &Genesis{
-			Config: &params.ChainConfig{ChainID: big.NewInt(1), EIP150Block: big.NewInt(0), EIP155Block: big.NewInt(2), HomesteadBlock: new(big.Int)},
-			Alloc:  GenesisAlloc{address: {Balance: funds}, deleteAddr: {Balance: new(big.Int)}},
+			Config: &params.ChainConfig{
+				ChainID:        big.NewInt(1),
+				EIP150Block:    big.NewInt(0),
+				EIP155Block:    big.NewInt(2),
+				HomesteadBlock: new(big.Int),
+			},
+			Alloc: GenesisAlloc{address: {Balance: funds}, deleteAddr: {Balance: new(big.Int)}},
 		}
-		genesis = gspec.MustCommit(db)
 	)
-
-	blockchain, _ := NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
-	defer blockchain.Stop()
-
-	blocks, _ := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 4, func(i int, block *BlockGen) {
+	genDb, blocks, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 4, func(i int, block *BlockGen) {
 		var (
 			tx      *types.Transaction
 			err     error
@@ -1480,6 +1453,9 @@ func TestEIP155Transition(t *testing.T) {
 		}
 	})
 
+	blockchain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	defer blockchain.Stop()
+
 	if _, err := blockchain.InsertChain(blocks); err != nil {
 		t.Fatal(err)
 	}
@@ -1500,8 +1476,13 @@ func TestEIP155Transition(t *testing.T) {
 	}
 
 	// generate an invalid chain id transaction
-	config := &params.ChainConfig{ChainID: big.NewInt(2), EIP150Block: big.NewInt(0), EIP155Block: big.NewInt(2), HomesteadBlock: new(big.Int)}
-	blocks, _ = GenerateChain(config, blocks[len(blocks)-1], ethash.NewFaker(), db, 4, func(i int, block *BlockGen) {
+	config := &params.ChainConfig{
+		ChainID:        big.NewInt(2),
+		EIP150Block:    big.NewInt(0),
+		EIP155Block:    big.NewInt(2),
+		HomesteadBlock: new(big.Int),
+	}
+	blocks, _ = GenerateChain(config, blocks[len(blocks)-1], ethash.NewFaker(), genDb, 4, func(i int, block *BlockGen) {
 		var (
 			tx      *types.Transaction
 			err     error
@@ -1526,7 +1507,6 @@ func TestEIP155Transition(t *testing.T) {
 func TestEIP161AccountRemoval(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		db      = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(1000000000)
@@ -1541,12 +1521,8 @@ func TestEIP161AccountRemoval(t *testing.T) {
 			},
 			Alloc: GenesisAlloc{address: {Balance: funds}},
 		}
-		genesis = gspec.MustCommit(db)
 	)
-	blockchain, _ := NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
-	defer blockchain.Stop()
-
-	blocks, _ := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 3, func(i int, block *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 3, func(i int, block *BlockGen) {
 		var (
 			tx     *types.Transaction
 			err    error
@@ -1566,6 +1542,9 @@ func TestEIP161AccountRemoval(t *testing.T) {
 		block.AddTx(tx)
 	})
 	// account must exist pre eip 161
+	blockchain, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	defer blockchain.Stop()
+
 	if _, err := blockchain.InsertChain(types.Blocks{blocks[0]}); err != nil {
 		t.Fatal(err)
 	}
@@ -1598,31 +1577,25 @@ func TestEIP161AccountRemoval(t *testing.T) {
 func TestBlockchainHeaderchainReorgConsistency(t *testing.T) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
-
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
 		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 64, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+	genDb, blocks, _ := GenerateChainWithGenesis(genesis, engine, 64, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 
 	// Generate a bunch of fork blocks, each side forking from the canonical chain
 	forks := make([]*types.Block, len(blocks))
 	for i := 0; i < len(forks); i++ {
-		parent := genesis
+		parent := genesis.ToBlock()
 		if i > 0 {
 			parent = blocks[i-1]
 		}
-		fork, _ := GenerateChain(params.TestChainConfig, parent, engine, db, 1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
+		fork, _ := GenerateChain(genesis.Config, parent, engine, genDb, 1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
 		forks[i] = fork[0]
 	}
 	// Import the canonical and fork chain side by side, verifying the current block
 	// and current header consistency
-	diskdb := rawdb.NewMemoryDatabase()
-	(&Genesis{BaseFee: big.NewInt(params.InitialBaseFee)}).MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -1647,30 +1620,24 @@ func TestBlockchainHeaderchainReorgConsistency(t *testing.T) {
 func TestTrieForkGC(t *testing.T) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
-
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
-		BaseFee: big.NewInt(params.InitialBaseFee),
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
+		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2*TriesInMemory, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+	genDb, blocks, _ := GenerateChainWithGenesis(genesis, engine, 2*TriesInMemory, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 
 	// Generate a bunch of fork blocks, each side forking from the canonical chain
 	forks := make([]*types.Block, len(blocks))
 	for i := 0; i < len(forks); i++ {
-		parent := genesis
+		parent := genesis.ToBlock()
 		if i > 0 {
 			parent = blocks[i-1]
 		}
-		fork, _ := GenerateChain(params.TestChainConfig, parent, engine, db, 1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
+		fork, _ := GenerateChain(genesis.Config, parent, engine, genDb, 1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
 		forks[i] = fork[0]
 	}
 	// Import the canonical and fork chain side by side, forcing the trie cache to cache both
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -1697,23 +1664,16 @@ func TestTrieForkGC(t *testing.T) {
 func TestLargeReorgTrieGC(t *testing.T) {
 	// Generate the original common chain segment and the two competing forks
 	engine := ethash.NewFaker()
-
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
-		BaseFee: big.NewInt(params.InitialBaseFee),
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
+		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
-
-	shared, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 64, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
-	original, _ := GenerateChain(params.TestChainConfig, shared[len(shared)-1], engine, db, 2*TriesInMemory, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
-	competitor, _ := GenerateChain(params.TestChainConfig, shared[len(shared)-1], engine, db, 2*TriesInMemory+1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{3}) })
+	genDb, shared, _ := GenerateChainWithGenesis(genesis, engine, 64, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+	original, _ := GenerateChain(genesis.Config, shared[len(shared)-1], engine, genDb, 2*TriesInMemory, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
+	competitor, _ := GenerateChain(genesis.Config, shared[len(shared)-1], engine, genDb, 2*TriesInMemory+1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{3}) })
 
 	// Import the shared chain and the original canonical one
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -1752,25 +1712,20 @@ func TestLargeReorgTrieGC(t *testing.T) {
 func TestBlockchainRecovery(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb   = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(1000000000)
 		gspec   = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{address: {Balance: funds}}}
-		genesis = gspec.MustCommit(gendb)
 	)
 	height := uint64(1024)
-	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, int(height), nil)
+	_, blocks, receipts := GenerateChainWithGenesis(gspec, ethash.NewFaker(), int(height), nil)
 
 	// Import the chain as a ancient-first node and ensure all pointers are updated
-	frdir := t.TempDir()
-
-	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), frdir, "", false)
+	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), t.TempDir(), "", false)
 	if err != nil {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
 	defer ancientDb.Close()
-	gspec.MustCommit(ancientDb)
 	ancient, _ := NewBlockChain(ancientDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 
 	headers := make([]*types.Header, len(blocks))
@@ -1807,7 +1762,7 @@ func TestBlockchainRecovery(t *testing.T) {
 // This test checks that InsertReceiptChain will roll back correctly when attempting to insert a side chain.
 func TestInsertReceiptChainRollback(t *testing.T) {
 	// Generate forked chain. The returned BlockChain object is used to process the side chain blocks.
-	tmpChain, sideblocks, canonblocks, err := getLongAndShortChains()
+	tmpChain, sideblocks, canonblocks, gspec, err := getLongAndShortChains()
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1838,9 +1793,7 @@ func TestInsertReceiptChainRollback(t *testing.T) {
 	}
 	defer ancientDb.Close()
 
-	gspec := Genesis{Config: params.AllEthashProtocolChanges}
-	gspec.MustCommit(ancientDb)
-	ancientChain, _ := NewBlockChain(ancientDb, nil, &gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	ancientChain, _ := NewBlockChain(ancientDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer ancientChain.Stop()
 
 	// Import the canonical header chain.
@@ -1887,25 +1840,19 @@ func TestInsertReceiptChainRollback(t *testing.T) {
 func TestLowDiffLongChain(t *testing.T) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
-		BaseFee: big.NewInt(params.InitialBaseFee),
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
+		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
-
 	// We must use a pretty long chain to ensure that the fork doesn't overtake us
 	// until after at least 128 blocks post tip
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 6*TriesInMemory, func(i int, b *BlockGen) {
+	genDb, blocks, _ := GenerateChainWithGenesis(genesis, engine, 6*TriesInMemory, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		b.OffsetTime(-9)
 	})
 
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -1914,7 +1861,7 @@ func TestLowDiffLongChain(t *testing.T) {
 	}
 	// Generate fork chain, starting from an early block
 	parent := blocks[10]
-	fork, _ := GenerateChain(params.TestChainConfig, parent, engine, db, 8*TriesInMemory, func(i int, b *BlockGen) {
+	fork, _ := GenerateChain(genesis.Config, parent, engine, genDb, 8*TriesInMemory, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{2})
 	})
 
@@ -1947,15 +1894,11 @@ func TestLowDiffLongChain(t *testing.T) {
 // 0:  the transition happens since genesis
 // 1:  the transition happens after some chain segments
 func testSideImport(t *testing.T, numCanonBlocksInSidechain, blocksBetweenCommonAncestorAndPruneblock int, mergePoint int) {
-	// Copy the TestChainConfig so we can modify it during tests
-	chainConfig := *params.TestChainConfig
 	// Generate a canonical chain to act as the main dataset
+	chainConfig := *params.TestChainConfig
 	var (
-		merger    = consensus.NewMerger(rawdb.NewMemoryDatabase())
-		genEngine = beacon.New(ethash.NewFaker())
-		runEngine = beacon.New(ethash.NewFaker())
-		db        = rawdb.NewMemoryDatabase()
-
+		merger = consensus.NewMerger(rawdb.NewMemoryDatabase())
+		engine = beacon.New(ethash.NewFaker())
 		key, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr   = crypto.PubkeyToAddress(key.PublicKey)
 		nonce  = uint64(0)
@@ -1965,13 +1908,10 @@ func testSideImport(t *testing.T, numCanonBlocksInSidechain, blocksBetweenCommon
 			Alloc:   GenesisAlloc{addr: {Balance: big.NewInt(math.MaxInt64)}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		signer  = types.LatestSigner(gspec.Config)
-		genesis = gspec.MustCommit(db)
+		signer = types.LatestSigner(gspec.Config)
 	)
 	// Generate and import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, runEngine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -1983,7 +1923,7 @@ func testSideImport(t *testing.T, numCanonBlocksInSidechain, blocksBetweenCommon
 		// Set the terminal total difficulty in the config
 		gspec.Config.TerminalTotalDifficulty = big.NewInt(0)
 	}
-	blocks, _ := GenerateChain(&chainConfig, genesis, genEngine, db, 2*TriesInMemory, func(i int, gen *BlockGen) {
+	genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, 2*TriesInMemory, func(i int, gen *BlockGen) {
 		tx, err := types.SignTx(types.NewTransaction(nonce, common.HexToAddress("deadbeef"), big.NewInt(100), 21000, big.NewInt(int64(i+1)*params.GWei), nil), signer, key)
 		if err != nil {
 			t.Fatalf("failed to create tx: %v", err)
@@ -2023,7 +1963,7 @@ func testSideImport(t *testing.T, numCanonBlocksInSidechain, blocksBetweenCommon
 	// Generate fork chain, make it longer than canon
 	parentIndex := lastPrunedIndex + blocksBetweenCommonAncestorAndPruneblock
 	parent := blocks[parentIndex]
-	fork, _ := GenerateChain(&chainConfig, parent, genEngine, db, 2*TriesInMemory, func(i int, b *BlockGen) {
+	fork, _ := GenerateChain(gspec.Config, parent, engine, genDb, 2*TriesInMemory, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{2})
 	})
 	// Prepend the parent(s)
@@ -2085,19 +2025,17 @@ func TestInsertKnownBlocks(t *testing.T)       { testInsertKnownChainData(t, "bl
 
 func testInsertKnownChainData(t *testing.T, typ string) {
 	engine := ethash.NewFaker()
-
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
 		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
+	genDb, blocks, receipts := GenerateChainWithGenesis(genesis, engine, 32, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 
-	blocks, receipts := GenerateChain(params.TestChainConfig, genesis, engine, db, 32, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 	// A longer chain but total difficulty is lower.
-	blocks2, receipts2 := GenerateChain(params.TestChainConfig, blocks[len(blocks)-1], engine, db, 65, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+	blocks2, receipts2 := GenerateChain(genesis.Config, blocks[len(blocks)-1], engine, genDb, 65, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+
 	// A shorter chain but total difficulty is higher.
-	blocks3, receipts3 := GenerateChain(params.TestChainConfig, blocks[len(blocks)-1], engine, db, 64, func(i int, b *BlockGen) {
+	blocks3, receipts3 := GenerateChain(genesis.Config, blocks[len(blocks)-1], engine, genDb, 64, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		b.OffsetTime(-9) // A higher difficulty
 	})
@@ -2106,10 +2044,9 @@ func testInsertKnownChainData(t *testing.T, typ string) {
 	if err != nil {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
-	gspec.MustCommit(chaindb)
 	defer chaindb.Close()
 
-	chain, err := NewBlockChain(chaindb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(chaindb, nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -2229,51 +2166,37 @@ func testInsertKnownChainDataWithMerging(t *testing.T, typ string, mergeHeight i
 	// Copy the TestChainConfig so we can modify it during tests
 	chainConfig := *params.TestChainConfig
 	var (
-		db    = rawdb.NewMemoryDatabase()
-		gspec = &Genesis{
+		genesis = &Genesis{
 			BaseFee: big.NewInt(params.InitialBaseFee),
 			Config:  &chainConfig,
 		}
-		genesis   = gspec.MustCommit(db)
-		runMerger = consensus.NewMerger(db)
-		runEngine = beacon.New(ethash.NewFaker())
-		genEngine = beacon.New(ethash.NewFaker())
+		engine = beacon.New(ethash.NewFaker())
 	)
-	applyMerge := func(engine *beacon.Beacon, height int) {
-		if engine != nil {
-			runMerger.FinalizePoS()
-			// Set the terminal total difficulty in the config
-			chainConfig.TerminalTotalDifficulty = big.NewInt(int64(height))
-		}
-	}
-
 	// Apply merging since genesis
 	if mergeHeight == 0 {
-		applyMerge(genEngine, 0)
+		genesis.Config.TerminalTotalDifficulty = big.NewInt(0)
 	}
-	blocks, receipts := GenerateChain(&chainConfig, genesis, genEngine, db, 32, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+	genDb, blocks, receipts := GenerateChainWithGenesis(genesis, engine, 32, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 
 	// Apply merging after the first segment
 	if mergeHeight == 1 {
-		applyMerge(genEngine, len(blocks))
+		genesis.Config.TerminalTotalDifficulty = big.NewInt(int64(len(blocks)))
 	}
 	// Longer chain and shorter chain
-	blocks2, receipts2 := GenerateChain(&chainConfig, blocks[len(blocks)-1], genEngine, db, 65, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
-	blocks3, receipts3 := GenerateChain(&chainConfig, blocks[len(blocks)-1], genEngine, db, 64, func(i int, b *BlockGen) {
+	blocks2, receipts2 := GenerateChain(genesis.Config, blocks[len(blocks)-1], engine, genDb, 65, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
+	blocks3, receipts3 := GenerateChain(genesis.Config, blocks[len(blocks)-1], engine, genDb, 64, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		b.OffsetTime(-9) // Time shifted, difficulty shouldn't be changed
 	})
 
 	// Import the shared chain and the original canonical one
-	dir := t.TempDir()
-	chaindb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), dir, "", false)
+	chaindb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), t.TempDir(), "", false)
 	if err != nil {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
-	(&Genesis{BaseFee: big.NewInt(params.InitialBaseFee)}).MustCommit(chaindb)
 	defer chaindb.Close()
 
-	chain, err := NewBlockChain(chaindb, nil, gspec, nil, runEngine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(chaindb, nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -2324,11 +2247,6 @@ func testInsertKnownChainDataWithMerging(t *testing.T, typ string, mergeHeight i
 			}
 		}
 	}
-
-	// Apply merging since genesis if required
-	if mergeHeight == 0 {
-		applyMerge(runEngine, 0)
-	}
 	if err := inserter(blocks, receipts); err != nil {
 		t.Fatalf("failed to insert chain data: %v", err)
 	}
@@ -2348,11 +2266,6 @@ func testInsertKnownChainDataWithMerging(t *testing.T, typ string, mergeHeight i
 	}
 	asserter(t, blocks[len(blocks)-1])
 
-	// Apply merging after the first segment
-	if mergeHeight == 1 {
-		applyMerge(runEngine, len(blocks))
-	}
-
 	// Import a longer chain with some known data as prefix.
 	if err := inserter(append(blocks, blocks2...), append(receipts, receipts2...)); err != nil {
 		t.Fatalf("failed to insert chain data: %v", err)
@@ -2377,36 +2290,30 @@ func testInsertKnownChainDataWithMerging(t *testing.T, typ string, mergeHeight i
 }
 
 // getLongAndShortChains returns two chains: A is longer, B is heavier.
-func getLongAndShortChains() (bc *BlockChain, longChain []*types.Block, heavyChain []*types.Block, err error) {
+func getLongAndShortChains() (*BlockChain, []*types.Block, []*types.Block, *Genesis, error) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
-		BaseFee: big.NewInt(params.InitialBaseFee),
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
+		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
-
 	// Generate and import the canonical chain,
 	// Offset the time, to keep the difficulty low
-	longChain, _ = GenerateChain(params.TestChainConfig, genesis, engine, db, 80, func(i int, b *BlockGen) {
+	genDb, longChain, _ := GenerateChainWithGenesis(genesis, engine, 80, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 	})
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
-		return nil, nil, nil, fmt.Errorf("failed to create tester chain: %v", err)
+		return nil, nil, nil, nil, fmt.Errorf("failed to create tester chain: %v", err)
 	}
-
 	// Generate fork chain, make it shorter than canon, with common ancestor pretty early
 	parentIndex := 3
 	parent := longChain[parentIndex]
-	heavyChainExt, _ := GenerateChain(params.TestChainConfig, parent, engine, db, 75, func(i int, b *BlockGen) {
+	heavyChainExt, _ := GenerateChain(genesis.Config, parent, engine, genDb, 75, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{2})
 		b.OffsetTime(-9)
 	})
+	var heavyChain []*types.Block
 	heavyChain = append(heavyChain, longChain[:parentIndex+1]...)
 	heavyChain = append(heavyChain, heavyChainExt...)
 
@@ -2425,14 +2332,14 @@ func getLongAndShortChains() (bc *BlockChain, longChain []*types.Block, heavyCha
 		shorterTd.Add(shorterTd, b.Difficulty())
 	}
 	if shorterTd.Cmp(longerTd) <= 0 {
-		return nil, nil, nil, fmt.Errorf("test is moot, heavyChain td (%v) must be larger than canon td (%v)", shorterTd, longerTd)
+		return nil, nil, nil, nil, fmt.Errorf("test is moot, heavyChain td (%v) must be larger than canon td (%v)", shorterTd, longerTd)
 	}
 	longerNum := longChain[len(longChain)-1].NumberU64()
 	shorterNum := heavyChain[len(heavyChain)-1].NumberU64()
 	if shorterNum >= longerNum {
-		return nil, nil, nil, fmt.Errorf("test is moot, heavyChain num (%v) must be lower than canon num (%v)", shorterNum, longerNum)
+		return nil, nil, nil, nil, fmt.Errorf("test is moot, heavyChain num (%v) must be lower than canon num (%v)", shorterNum, longerNum)
 	}
-	return chain, longChain, heavyChain, nil
+	return chain, longChain, heavyChain, genesis, nil
 }
 
 // TestReorgToShorterRemovesCanonMapping tests that if we
@@ -2441,7 +2348,7 @@ func getLongAndShortChains() (bc *BlockChain, longChain []*types.Block, heavyCha
 // 3. Then there should be no canon mapping for the block at height X
 // 4. The forked block should still be retrievable by hash
 func TestReorgToShorterRemovesCanonMapping(t *testing.T) {
-	chain, canonblocks, sideblocks, err := getLongAndShortChains()
+	chain, canonblocks, sideblocks, _, err := getLongAndShortChains()
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -2477,7 +2384,7 @@ func TestReorgToShorterRemovesCanonMapping(t *testing.T) {
 // as TestReorgToShorterRemovesCanonMapping, but applied on headerchain
 // imports -- that is, for fast sync
 func TestReorgToShorterRemovesCanonMappingHeaderChain(t *testing.T) {
-	chain, canonblocks, sideblocks, err := getLongAndShortChains()
+	chain, canonblocks, sideblocks, _, err := getLongAndShortChains()
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -2520,7 +2427,6 @@ func TestReorgToShorterRemovesCanonMappingHeaderChain(t *testing.T) {
 func TestTransactionIndices(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb   = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(100000000000000000)
@@ -2529,18 +2435,17 @@ func TestTransactionIndices(t *testing.T) {
 			Alloc:   GenesisAlloc{address: {Balance: funds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(gendb)
-		signer  = types.LatestSigner(gspec.Config)
+		signer = types.LatestSigner(gspec.Config)
 	)
 	height := uint64(128)
-	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, int(height), func(i int, block *BlockGen) {
+	genDb, blocks, receipts := GenerateChainWithGenesis(gspec, ethash.NewFaker(), int(height), func(i int, block *BlockGen) {
 		tx, err := types.SignTx(types.NewTransaction(block.TxNonce(address), common.Address{0x00}, big.NewInt(1000), params.TxGas, block.header.BaseFee, nil), signer, key)
 		if err != nil {
 			panic(err)
 		}
 		block.AddTx(tx)
 	})
-	blocks2, _ := GenerateChain(gspec.Config, blocks[len(blocks)-1], ethash.NewFaker(), gendb, 10, nil)
+	blocks2, _ := GenerateChain(gspec.Config, blocks[len(blocks)-1], ethash.NewFaker(), genDb, 10, nil)
 
 	check := func(tail *uint64, chain *BlockChain) {
 		stored := rawdb.ReadTxIndexTail(chain.db)
@@ -2580,8 +2485,6 @@ func TestTransactionIndices(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
-	gspec.MustCommit(ancientDb)
-
 	// Import all blocks into ancient db
 	l := uint64(0)
 	chain, err := NewBlockChain(ancientDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, &l)
@@ -2608,7 +2511,6 @@ func TestTransactionIndices(t *testing.T) {
 		if err != nil {
 			t.Fatalf("failed to create temp freezer db: %v", err)
 		}
-		gspec.MustCommit(ancientDb)
 		l := l
 		chain, err = NewBlockChain(ancientDb, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, &l)
 		if err != nil {
@@ -2630,7 +2532,6 @@ func TestTransactionIndices(t *testing.T) {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
 	defer ancientDb.Close()
-	gspec.MustCommit(ancientDb)
 
 	limit = []uint64{0, 64 /* drop stale */, 32 /* shorten history */, 64 /* extend history */, 0 /* restore all */}
 	tails := []uint64{0, 67 /* 130 - 64 + 1 */, 100 /* 131 - 32 + 1 */, 69 /* 132 - 64 + 1 */, 0}
@@ -2650,16 +2551,13 @@ func TestTransactionIndices(t *testing.T) {
 func TestSkipStaleTxIndicesInSnapSync(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb   = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(100000000000000000)
 		gspec   = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{address: {Balance: funds}}}
-		genesis = gspec.MustCommit(gendb)
 		signer  = types.LatestSigner(gspec.Config)
 	)
-	height := uint64(128)
-	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, int(height), func(i int, block *BlockGen) {
+	_, blocks, receipts := GenerateChainWithGenesis(gspec, ethash.NewFaker(), 128, func(i int, block *BlockGen) {
 		tx, err := types.SignTx(types.NewTransaction(block.TxNonce(address), common.Address{0x00}, big.NewInt(1000), params.TxGas, block.header.BaseFee, nil), signer, key)
 		if err != nil {
 			panic(err)
@@ -2701,13 +2599,11 @@ func TestSkipStaleTxIndicesInSnapSync(t *testing.T) {
 		}
 	}
 
-	frdir := t.TempDir()
-	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), frdir, "", false)
+	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), t.TempDir(), "", false)
 	if err != nil {
 		t.Fatalf("failed to create temp freezer db: %v", err)
 	}
 	defer ancientDb.Close()
-	gspec.MustCommit(ancientDb)
 
 	// Import all blocks into ancient db, only HEAD-32 indices are kept.
 	l := uint64(32)
@@ -2751,8 +2647,6 @@ func benchmarkLargeNumberOfValueToNonexisting(b *testing.B, numTxs, numBlocks in
 	)
 	// Generate the original common chain segment and the two competing forks
 	engine := ethash.NewFaker()
-	db := rawdb.NewMemoryDatabase()
-	genesis := gspec.MustCommit(db)
 
 	blockGenerator := func(i int, block *BlockGen) {
 		block.SetCoinbase(common.Address{1})
@@ -2767,15 +2661,12 @@ func benchmarkLargeNumberOfValueToNonexisting(b *testing.B, numTxs, numBlocks in
 		}
 	}
 
-	shared, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, numBlocks, blockGenerator)
+	_, shared, _ := GenerateChainWithGenesis(gspec, engine, numBlocks, blockGenerator)
 	b.StopTimer()
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		// Import the shared chain and the original canonical one
-		diskdb := rawdb.NewMemoryDatabase()
-		gspec.MustCommit(diskdb)
-
-		chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+		chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 		if err != nil {
 			b.Fatalf("failed to create tester chain: %v", err)
 		}
@@ -2849,19 +2740,14 @@ func BenchmarkBlockChain_1x1000Executions(b *testing.B) {
 func TestSideImportPrunedBlocks(t *testing.T) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
-	db := rawdb.NewMemoryDatabase()
-	gspec := &Genesis{
-		BaseFee: big.NewInt(params.InitialBaseFee),
+	genesis := &Genesis{
 		Config:  params.TestChainConfig,
+		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	genesis := gspec.MustCommit(db)
-
 	// Generate and import the canonical chain
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2*TriesInMemory, nil)
-	diskdb := rawdb.NewMemoryDatabase()
+	_, blocks, _ := GenerateChainWithGenesis(genesis, engine, 2*TriesInMemory, nil)
 
-	gspec.MustCommit(diskdb)
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, genesis, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -2899,11 +2785,9 @@ func TestSideImportPrunedBlocks(t *testing.T) {
 // first, but the journal wiped the entire state object on create-revert.
 func TestDeleteCreateRevert(t *testing.T) {
 	var (
-		aa = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
-		bb = common.HexToAddress("0x000000000000000000000000000000000000bbbb")
-		// Generate a canonical chain to act as the main dataset
+		aa     = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
+		bb     = common.HexToAddress("0x000000000000000000000000000000000000bbbb")
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
 
 		// A sender who makes transactions, has some funds
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
@@ -2937,10 +2821,9 @@ func TestDeleteCreateRevert(t *testing.T) {
 				},
 			},
 		}
-		genesis = gspec.MustCommit(db)
 	)
 
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 1, func(i int, b *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		// One transaction to AAAA
 		tx, _ := types.SignTx(types.NewTransaction(0, aa,
@@ -2952,10 +2835,7 @@ func TestDeleteCreateRevert(t *testing.T) {
 		b.AddTx(tx)
 	})
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -2973,9 +2853,8 @@ func TestDeleteCreateRevert(t *testing.T) {
 // and then the new slots exist
 func TestDeleteRecreateSlots(t *testing.T) {
 	var (
-		// Generate a canonical chain to act as the main dataset
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
+
 		// A sender who makes transactions, has some funds
 		key, _    = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address   = crypto.PubkeyToAddress(key.PublicKey)
@@ -3050,9 +2929,7 @@ func TestDeleteRecreateSlots(t *testing.T) {
 			},
 		},
 	}
-	genesis := gspec.MustCommit(db)
-
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 1, func(i int, b *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		// One transaction to AA, to kill it
 		tx, _ := types.SignTx(types.NewTransaction(0, aa,
@@ -3064,9 +2941,7 @@ func TestDeleteRecreateSlots(t *testing.T) {
 		b.AddTx(tx)
 	})
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{
 		Debug:  true,
 		Tracer: logger.NewJSONLogger(nil, os.Stdout),
 	}, nil, nil)
@@ -3100,9 +2975,8 @@ func TestDeleteRecreateSlots(t *testing.T) {
 // Expected outcome is that _all_ slots are cleared from A
 func TestDeleteRecreateAccount(t *testing.T) {
 	var (
-		// Generate a canonical chain to act as the main dataset
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
+
 		// A sender who makes transactions, has some funds
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
@@ -3130,9 +3004,8 @@ func TestDeleteRecreateAccount(t *testing.T) {
 			},
 		},
 	}
-	genesis := gspec.MustCommit(db)
 
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 1, func(i int, b *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		// One transaction to AA, to kill it
 		tx, _ := types.SignTx(types.NewTransaction(0, aa,
@@ -3144,9 +3017,7 @@ func TestDeleteRecreateAccount(t *testing.T) {
 		b.AddTx(tx)
 	})
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{
 		Debug:  true,
 		Tracer: logger.NewJSONLogger(nil, os.Stdout),
 	}, nil, nil)
@@ -3176,9 +3047,8 @@ func TestDeleteRecreateAccount(t *testing.T) {
 // and then the new slots exist
 func TestDeleteRecreateSlotsAcrossManyBlocks(t *testing.T) {
 	var (
-		// Generate a canonical chain to act as the main dataset
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
+
 		// A sender who makes transactions, has some funds
 		key, _    = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address   = crypto.PubkeyToAddress(key.PublicKey)
@@ -3254,7 +3124,6 @@ func TestDeleteRecreateSlotsAcrossManyBlocks(t *testing.T) {
 			},
 		},
 	}
-	genesis := gspec.MustCommit(db)
 	var nonce uint64
 
 	type expectation struct {
@@ -3291,7 +3160,7 @@ func TestDeleteRecreateSlotsAcrossManyBlocks(t *testing.T) {
 		return tx
 	}
 
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 150, func(i int, b *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 150, func(i int, b *BlockGen) {
 		var exp = new(expectation)
 		exp.blocknum = i + 1
 		exp.values = make(map[int]int)
@@ -3317,9 +3186,7 @@ func TestDeleteRecreateSlotsAcrossManyBlocks(t *testing.T) {
 		current = exp
 	})
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{
 		//Debug:  true,
 		//Tracer: vm.NewJSONLogger(nil, os.Stdout),
 	}, nil, nil)
@@ -3378,9 +3245,8 @@ func TestDeleteRecreateSlotsAcrossManyBlocks(t *testing.T) {
 //
 func TestInitThenFailCreateContract(t *testing.T) {
 	var (
-		// Generate a canonical chain to act as the main dataset
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
+
 		// A sender who makes transactions, has some funds
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
@@ -3439,9 +3305,8 @@ func TestInitThenFailCreateContract(t *testing.T) {
 			},
 		},
 	}
-	genesis := gspec.MustCommit(db)
 	nonce := uint64(0)
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 4, func(i int, b *BlockGen) {
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 4, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 		// One transaction to BB
 		tx, _ := types.SignTx(types.NewTransaction(nonce, bb,
@@ -3451,9 +3316,7 @@ func TestInitThenFailCreateContract(t *testing.T) {
 	})
 
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{
 		//Debug:  true,
 		//Tracer: vm.NewJSONLogger(nil, os.Stdout),
 	}, nil, nil)
@@ -3490,11 +3353,8 @@ func TestInitThenFailCreateContract(t *testing.T) {
 // correctly.
 func TestEIP2718Transition(t *testing.T) {
 	var (
-		aa = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
-
-		// Generate a canonical chain to act as the main dataset
+		aa     = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
 
 		// A sender who makes transactions, has some funds
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
@@ -3517,10 +3377,9 @@ func TestEIP2718Transition(t *testing.T) {
 				},
 			},
 		}
-		genesis = gspec.MustCommit(db)
 	)
-
-	blocks, _ := GenerateChain(gspec.Config, genesis, engine, db, 1, func(i int, b *BlockGen) {
+	// Generate blocks
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 
 		// One transaction to 0xAAAA
@@ -3540,10 +3399,7 @@ func TestEIP2718Transition(t *testing.T) {
 	})
 
 	// Import the canonical chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -3572,11 +3428,8 @@ func TestEIP2718Transition(t *testing.T) {
 // 6. Legacy transaction behave as expected (e.g. gasPrice = gasFeeCap = gasTipCap).
 func TestEIP1559Transition(t *testing.T) {
 	var (
-		aa = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
-
-		// Generate a canonical chain to act as the main dataset
+		aa     = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
 
 		// A sender who makes transactions, has some funds
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
@@ -3606,10 +3459,9 @@ func TestEIP1559Transition(t *testing.T) {
 
 	gspec.Config.BerlinBlock = common.Big0
 	gspec.Config.LondonBlock = common.Big0
-	genesis := gspec.MustCommit(db)
 	signer := types.LatestSigner(gspec.Config)
 
-	blocks, _ := GenerateChain(gspec.Config, genesis, engine, db, 1, func(i int, b *BlockGen) {
+	genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
 
 		// One transaction to 0xAAAA
@@ -3633,11 +3485,7 @@ func TestEIP1559Transition(t *testing.T) {
 
 		b.AddTx(tx)
 	})
-
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -3673,7 +3521,7 @@ func TestEIP1559Transition(t *testing.T) {
 		t.Fatalf("sender balance incorrect: expected %d, got %d", expected, actual)
 	}
 
-	blocks, _ = GenerateChain(gspec.Config, block, engine, db, 1, func(i int, b *BlockGen) {
+	blocks, _ = GenerateChain(gspec.Config, block, engine, genDb, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{2})
 
 		txdata := &types.LegacyTx{
@@ -3720,7 +3568,6 @@ func TestSetCanonical(t *testing.T) {
 	//log.Root().SetHandler(log.LvlFilterHandler(log.LvlDebug, log.StreamHandler(os.Stderr, log.TerminalFormat(true))))
 
 	var (
-		db      = rawdb.NewMemoryDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(100000000000000000)
@@ -3729,22 +3576,18 @@ func TestSetCanonical(t *testing.T) {
 			Alloc:   GenesisAlloc{address: {Balance: funds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(db)
-		signer  = types.LatestSigner(gspec.Config)
-		engine  = ethash.NewFaker()
+		signer = types.LatestSigner(gspec.Config)
+		engine = ethash.NewFaker()
 	)
 	// Generate and import the canonical chain
-	canon, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2*TriesInMemory, func(i int, gen *BlockGen) {
+	_, canon, _ := GenerateChainWithGenesis(gspec, engine, 2*TriesInMemory, func(i int, gen *BlockGen) {
 		tx, err := types.SignTx(types.NewTransaction(gen.TxNonce(address), common.Address{0x00}, big.NewInt(1000), params.TxGas, gen.header.BaseFee, nil), signer, key)
 		if err != nil {
 			panic(err)
 		}
 		gen.AddTx(tx)
 	})
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-
-	chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create tester chain: %v", err)
 	}
@@ -3753,7 +3596,7 @@ func TestSetCanonical(t *testing.T) {
 	}
 
 	// Generate the side chain and import them
-	side, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2*TriesInMemory, func(i int, gen *BlockGen) {
+	_, side, _ := GenerateChainWithGenesis(gspec, engine, 2*TriesInMemory, func(i int, gen *BlockGen) {
 		tx, err := types.SignTx(types.NewTransaction(gen.TxNonce(address), common.Address{0x00}, big.NewInt(1), params.TxGas, gen.header.BaseFee, nil), signer, key)
 		if err != nil {
 			panic(err)
@@ -3835,22 +3678,18 @@ func TestCanonicalHashMarker(t *testing.T) {
 	}
 	for _, c := range cases {
 		var (
-			db    = rawdb.NewMemoryDatabase()
 			gspec = &Genesis{
 				Config:  params.TestChainConfig,
 				Alloc:   GenesisAlloc{},
 				BaseFee: big.NewInt(params.InitialBaseFee),
 			}
-			genesis = gspec.MustCommit(db)
-			engine  = ethash.NewFaker()
+			engine = ethash.NewFaker()
 		)
-		forkA, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, c.forkA, func(i int, gen *BlockGen) {})
-		forkB, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, c.forkB, func(i int, gen *BlockGen) {})
+		_, forkA, _ := GenerateChainWithGenesis(gspec, engine, c.forkA, func(i int, gen *BlockGen) {})
+		_, forkB, _ := GenerateChainWithGenesis(gspec, engine, c.forkB, func(i int, gen *BlockGen) {})
 
 		// Initialize test chain
-		diskdb := rawdb.NewMemoryDatabase()
-		gspec.MustCommit(diskdb)
-		chain, err := NewBlockChain(diskdb, nil, gspec, nil, engine, vm.Config{}, nil, nil)
+		chain, err := NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, engine, vm.Config{}, nil, nil)
 		if err != nil {
 			t.Fatalf("failed to create tester chain: %v", err)
 		}
diff --git a/core/chain_makers.go b/core/chain_makers.go
index c7bf60a4b0..88a1c4e870 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -23,6 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/consensus/misc"
+	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -284,6 +285,19 @@ func GenerateChain(config *params.ChainConfig, parent *types.Block, engine conse
 	return blocks, receipts
 }
 
+// GenerateChainWithGenesis is a wrapper of GenerateChain which will initialize
+// genesis block to database first according to the provided genesis specification
+// then generate chain on top.
+func GenerateChainWithGenesis(genesis *Genesis, engine consensus.Engine, n int, gen func(int, *BlockGen)) (ethdb.Database, []*types.Block, []types.Receipts) {
+	db := rawdb.NewMemoryDatabase()
+	_, err := genesis.Commit(db)
+	if err != nil {
+		panic(err)
+	}
+	blocks, receipts := GenerateChain(genesis.Config, genesis.ToBlock(), engine, db, n, gen)
+	return db, blocks, receipts
+}
+
 func makeHeader(chain consensus.ChainReader, parent *types.Block, state *state.StateDB, engine consensus.Engine) *types.Header {
 	var time uint64
 	if parent.Time() == 0 {
@@ -316,8 +330,8 @@ func makeHeader(chain consensus.ChainReader, parent *types.Block, state *state.S
 }
 
 // makeHeaderChain creates a deterministic chain of headers rooted at parent.
-func makeHeaderChain(parent *types.Header, n int, engine consensus.Engine, db ethdb.Database, seed int) []*types.Header {
-	blocks := makeBlockChain(types.NewBlockWithHeader(parent), n, engine, db, seed)
+func makeHeaderChain(chainConfig *params.ChainConfig, parent *types.Header, n int, engine consensus.Engine, db ethdb.Database, seed int) []*types.Header {
+	blocks := makeBlockChain(chainConfig, types.NewBlockWithHeader(parent), n, engine, db, seed)
 	headers := make([]*types.Header, len(blocks))
 	for i, block := range blocks {
 		headers[i] = block.Header()
@@ -325,14 +339,32 @@ func makeHeaderChain(parent *types.Header, n int, engine consensus.Engine, db et
 	return headers
 }
 
+// makeHeaderChainWithGenesis creates a deterministic chain of headers from genesis.
+func makeHeaderChainWithGenesis(genesis *Genesis, n int, engine consensus.Engine, seed int) (ethdb.Database, []*types.Header) {
+	db, blocks := makeBlockChainWithGenesis(genesis, n, engine, seed)
+	headers := make([]*types.Header, len(blocks))
+	for i, block := range blocks {
+		headers[i] = block.Header()
+	}
+	return db, headers
+}
+
 // makeBlockChain creates a deterministic chain of blocks rooted at parent.
-func makeBlockChain(parent *types.Block, n int, engine consensus.Engine, db ethdb.Database, seed int) []*types.Block {
-	blocks, _ := GenerateChain(params.TestChainConfig, parent, engine, db, n, func(i int, b *BlockGen) {
+func makeBlockChain(chainConfig *params.ChainConfig, parent *types.Block, n int, engine consensus.Engine, db ethdb.Database, seed int) []*types.Block {
+	blocks, _ := GenerateChain(chainConfig, parent, engine, db, n, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{0: byte(seed), 19: byte(i)})
 	})
 	return blocks
 }
 
+// makeBlockChain creates a deterministic chain of blocks from genesis
+func makeBlockChainWithGenesis(genesis *Genesis, n int, engine consensus.Engine, seed int) (ethdb.Database, []*types.Block) {
+	db, blocks, _ := GenerateChainWithGenesis(genesis, engine, n, func(i int, b *BlockGen) {
+		b.SetCoinbase(common.Address{0: byte(seed), 19: byte(i)})
+	})
+	return db, blocks
+}
+
 type fakeChainReader struct {
 	config *params.ChainConfig
 }
diff --git a/core/dao_test.go b/core/dao_test.go
index 8089b5470a..44405447de 100644
--- a/core/dao_test.go
+++ b/core/dao_test.go
@@ -34,13 +34,11 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	chainConfig.HomesteadBlock = big.NewInt(0)
 
 	// Generate a common prefix for both pro-forkers and non-forkers
-	db := rawdb.NewMemoryDatabase()
 	gspec := &Genesis{
 		BaseFee: big.NewInt(params.InitialBaseFee),
 		Config:  &chainConfig,
 	}
-	genesis := gspec.MustCommit(db)
-	prefix, _ := GenerateChain(&chainConfig, genesis, ethash.NewFaker(), db, int(forkBlock.Int64()-1), func(i int, gen *BlockGen) {})
+	genDb, prefix, _ := GenerateChainWithGenesis(gspec, ethash.NewFaker(), int(forkBlock.Int64()-1), func(i int, gen *BlockGen) {})
 
 	// Create the concurrent, conflicting two nodes
 	proDb := rawdb.NewMemoryDatabase()
@@ -52,8 +50,6 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		BaseFee: big.NewInt(params.InitialBaseFee),
 		Config:  &proConf,
 	}
-	gspec.MustCommit(proDb)
-
 	proBc, _ := NewBlockChain(proDb, nil, progspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer proBc.Stop()
 
@@ -66,8 +62,6 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		BaseFee: big.NewInt(params.InitialBaseFee),
 		Config:  &conConf,
 	}
-	gspec.MustCommit(conDb)
-
 	conBc, _ := NewBlockChain(conDb, nil, congspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer conBc.Stop()
 
@@ -80,9 +74,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	// Try to expand both pro-fork and non-fork chains iteratively with other camp's blocks
 	for i := int64(0); i < params.DAOForkExtraRange.Int64(); i++ {
 		// Create a pro-fork block, and try to feed into the no-fork chain
-		db = rawdb.NewMemoryDatabase()
-		congspec.MustCommit(db)
-		bc, _ := NewBlockChain(db, nil, congspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+		bc, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, congspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 		defer bc.Stop()
 
 		blocks := conBc.GetBlocksFromHash(conBc.CurrentBlock().Hash(), int(conBc.CurrentBlock().NumberU64()))
@@ -95,19 +87,17 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		if err := bc.stateCache.TrieDB().Commit(bc.CurrentHeader().Root, true, nil); err != nil {
 			t.Fatalf("failed to commit contra-fork head for expansion: %v", err)
 		}
-		blocks, _ = GenerateChain(&proConf, conBc.CurrentBlock(), ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&proConf, conBc.CurrentBlock(), ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 		if _, err := conBc.InsertChain(blocks); err == nil {
 			t.Fatalf("contra-fork chain accepted pro-fork block: %v", blocks[0])
 		}
 		// Create a proper no-fork block for the contra-forker
-		blocks, _ = GenerateChain(&conConf, conBc.CurrentBlock(), ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&conConf, conBc.CurrentBlock(), ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 		if _, err := conBc.InsertChain(blocks); err != nil {
 			t.Fatalf("contra-fork chain didn't accepted no-fork block: %v", err)
 		}
 		// Create a no-fork block, and try to feed into the pro-fork chain
-		db = rawdb.NewMemoryDatabase()
-		progspec.MustCommit(db)
-		bc, _ = NewBlockChain(db, nil, progspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+		bc, _ = NewBlockChain(rawdb.NewMemoryDatabase(), nil, progspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 		defer bc.Stop()
 
 		blocks = proBc.GetBlocksFromHash(proBc.CurrentBlock().Hash(), int(proBc.CurrentBlock().NumberU64()))
@@ -120,20 +110,18 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		if err := bc.stateCache.TrieDB().Commit(bc.CurrentHeader().Root, true, nil); err != nil {
 			t.Fatalf("failed to commit pro-fork head for expansion: %v", err)
 		}
-		blocks, _ = GenerateChain(&conConf, proBc.CurrentBlock(), ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&conConf, proBc.CurrentBlock(), ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 		if _, err := proBc.InsertChain(blocks); err == nil {
 			t.Fatalf("pro-fork chain accepted contra-fork block: %v", blocks[0])
 		}
 		// Create a proper pro-fork block for the pro-forker
-		blocks, _ = GenerateChain(&proConf, proBc.CurrentBlock(), ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&proConf, proBc.CurrentBlock(), ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 		if _, err := proBc.InsertChain(blocks); err != nil {
 			t.Fatalf("pro-fork chain didn't accepted pro-fork block: %v", err)
 		}
 	}
 	// Verify that contra-forkers accept pro-fork extra-datas after forking finishes
-	db = rawdb.NewMemoryDatabase()
-	congspec.MustCommit(db)
-	bc, _ := NewBlockChain(db, nil, congspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	bc, _ := NewBlockChain(rawdb.NewMemoryDatabase(), nil, congspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer bc.Stop()
 
 	blocks := conBc.GetBlocksFromHash(conBc.CurrentBlock().Hash(), int(conBc.CurrentBlock().NumberU64()))
@@ -146,14 +134,12 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	if err := bc.stateCache.TrieDB().Commit(bc.CurrentHeader().Root, true, nil); err != nil {
 		t.Fatalf("failed to commit contra-fork head for expansion: %v", err)
 	}
-	blocks, _ = GenerateChain(&proConf, conBc.CurrentBlock(), ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+	blocks, _ = GenerateChain(&proConf, conBc.CurrentBlock(), ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 	if _, err := conBc.InsertChain(blocks); err != nil {
 		t.Fatalf("contra-fork chain didn't accept pro-fork block post-fork: %v", err)
 	}
 	// Verify that pro-forkers accept contra-fork extra-datas after forking finishes
-	db = rawdb.NewMemoryDatabase()
-	progspec.MustCommit(db)
-	bc, _ = NewBlockChain(db, nil, progspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	bc, _ = NewBlockChain(rawdb.NewMemoryDatabase(), nil, progspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer bc.Stop()
 
 	blocks = proBc.GetBlocksFromHash(proBc.CurrentBlock().Hash(), int(proBc.CurrentBlock().NumberU64()))
@@ -166,7 +152,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	if err := bc.stateCache.TrieDB().Commit(bc.CurrentHeader().Root, true, nil); err != nil {
 		t.Fatalf("failed to commit pro-fork head for expansion: %v", err)
 	}
-	blocks, _ = GenerateChain(&conConf, proBc.CurrentBlock(), ethash.NewFaker(), db, 1, func(i int, gen *BlockGen) {})
+	blocks, _ = GenerateChain(&conConf, proBc.CurrentBlock(), ethash.NewFaker(), genDb, 1, func(i int, gen *BlockGen) {})
 	if _, err := proBc.InsertChain(blocks); err != nil {
 		t.Fatalf("pro-fork chain didn't accept contra-fork block post-fork: %v", err)
 	}
diff --git a/core/headerchain_test.go b/core/headerchain_test.go
index ed0522671f..fe083b0031 100644
--- a/core/headerchain_test.go
+++ b/core/headerchain_test.go
@@ -27,7 +27,6 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 )
 
@@ -70,19 +69,18 @@ func testInsert(t *testing.T, hc *HeaderChain, chain []*types.Header, wantStatus
 // This test checks status reporting of InsertHeaderChain.
 func TestHeaderInsertion(t *testing.T) {
 	var (
-		db      = rawdb.NewMemoryDatabase()
-		genesis = (&Genesis{BaseFee: big.NewInt(params.InitialBaseFee)}).MustCommit(db)
+		db    = rawdb.NewMemoryDatabase()
+		gspec = &Genesis{BaseFee: big.NewInt(params.InitialBaseFee), Config: params.AllEthashProtocolChanges}
 	)
-
-	hc, err := NewHeaderChain(db, params.AllEthashProtocolChanges, ethash.NewFaker(), func() bool { return false })
+	gspec.Commit(db)
+	hc, err := NewHeaderChain(db, gspec.Config, ethash.NewFaker(), func() bool { return false })
 	if err != nil {
 		t.Fatal(err)
 	}
 	// chain A: G->A1->A2...A128
-	chainA := makeHeaderChain(genesis.Header(), 128, ethash.NewFaker(), db, 10)
+	genDb, chainA := makeHeaderChainWithGenesis(gspec, 128, ethash.NewFaker(), 10)
 	// chain B: G->A1->B1...B128
-	chainB := makeHeaderChain(chainA[0], 128, ethash.NewFaker(), db, 10)
-	log.Root().SetHandler(log.StdoutHandler)
+	chainB := makeHeaderChain(gspec.Config, chainA[0], 128, ethash.NewFaker(), genDb, 10)
 
 	forker := NewForkChoice(hc, nil)
 	// Inserting 64 headers on an empty chain, expecting
diff --git a/core/rlp_test.go b/core/rlp_test.go
index bf5a934ce5..a2fb4937f8 100644
--- a/core/rlp_test.go
+++ b/core/rlp_test.go
@@ -23,7 +23,6 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
@@ -33,10 +32,9 @@ import (
 
 func getBlock(transactions int, uncles int, dataSize int) *types.Block {
 	var (
-		aa = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
-		// Generate a canonical chain to act as the main dataset
+		aa     = common.HexToAddress("0x000000000000000000000000000000000000aaaa")
 		engine = ethash.NewFaker()
-		db     = rawdb.NewMemoryDatabase()
+
 		// A sender who makes transactions, has some funds
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
@@ -45,11 +43,9 @@ func getBlock(transactions int, uncles int, dataSize int) *types.Block {
 			Config: params.TestChainConfig,
 			Alloc:  GenesisAlloc{address: {Balance: funds}},
 		}
-		genesis = gspec.MustCommit(db)
 	)
-
 	// We need to generate as many blocks +1 as uncles
-	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, uncles+1,
+	_, blocks, _ := GenerateChainWithGenesis(gspec, engine, uncles+1,
 		func(n int, b *BlockGen) {
 			if n == uncles {
 				// Add transactions and stuff on the last block
diff --git a/core/state_processor_test.go b/core/state_processor_test.go
index 42faa28d05..1df4a0e804 100644
--- a/core/state_processor_test.go
+++ b/core/state_processor_test.go
@@ -91,7 +91,6 @@ func TestStateProcessorErrors(t *testing.T) {
 					},
 				},
 			}
-			genesis       = gspec.MustCommit(db)
 			blockchain, _ = NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 		)
 		defer blockchain.Stop()
@@ -197,7 +196,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				want: "could not apply tx 0 [0xd82a0c2519acfeac9a948258c47e784acd20651d9d80f9a1c67b4137651c3a24]: insufficient funds for gas * price + value: address 0x71562b71999873DB5b286dF957af199Ec94617F7 have 1000000000000000000 want 2431633873983640103894990685182446064918669677978451844828609264166175722438635000",
 			},
 		} {
-			block := GenerateBadBlock(genesis, ethash.NewFaker(), tt.txs, gspec.Config)
+			block := GenerateBadBlock(gspec.ToBlock(), ethash.NewFaker(), tt.txs, gspec.Config)
 			_, err := blockchain.InsertChain(types.Blocks{block})
 			if err == nil {
 				t.Fatal("block imported without errors")
@@ -232,7 +231,6 @@ func TestStateProcessorErrors(t *testing.T) {
 					},
 				},
 			}
-			genesis       = gspec.MustCommit(db)
 			blockchain, _ = NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 		)
 		defer blockchain.Stop()
@@ -247,7 +245,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				want: "could not apply tx 0 [0x88626ac0d53cb65308f2416103c62bb1f18b805573d4f96a3640bbbfff13c14f]: transaction type not supported",
 			},
 		} {
-			block := GenerateBadBlock(genesis, ethash.NewFaker(), tt.txs, gspec.Config)
+			block := GenerateBadBlock(gspec.ToBlock(), ethash.NewFaker(), tt.txs, gspec.Config)
 			_, err := blockchain.InsertChain(types.Blocks{block})
 			if err == nil {
 				t.Fatal("block imported without errors")
@@ -272,7 +270,6 @@ func TestStateProcessorErrors(t *testing.T) {
 					},
 				},
 			}
-			genesis       = gspec.MustCommit(db)
 			blockchain, _ = NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 		)
 		defer blockchain.Stop()
@@ -287,7 +284,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				want: "could not apply tx 0 [0x88626ac0d53cb65308f2416103c62bb1f18b805573d4f96a3640bbbfff13c14f]: sender not an eoa: address 0x71562b71999873DB5b286dF957af199Ec94617F7, codehash: 0x9280914443471259d4570a8661015ae4a5b80186dbc619658fb494bebc3da3d1",
 			},
 		} {
-			block := GenerateBadBlock(genesis, ethash.NewFaker(), tt.txs, gspec.Config)
+			block := GenerateBadBlock(gspec.ToBlock(), ethash.NewFaker(), tt.txs, gspec.Config)
 			_, err := blockchain.InsertChain(types.Blocks{block})
 			if err == nil {
 				t.Fatal("block imported without errors")
diff --git a/eth/catalyst/api_test.go b/eth/catalyst/api_test.go
index 0d945993eb..7e8f322df5 100644
--- a/eth/catalyst/api_test.go
+++ b/eth/catalyst/api_test.go
@@ -28,7 +28,6 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/beacon"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
@@ -51,10 +50,9 @@ var (
 )
 
 func generatePreMergeChain(n int) (*core.Genesis, []*types.Block) {
-	db := rawdb.NewMemoryDatabase()
-	config := params.AllEthashProtocolChanges
+	config := *params.AllEthashProtocolChanges
 	genesis := &core.Genesis{
-		Config:     config,
+		Config:     &config,
 		Alloc:      core.GenesisAlloc{testAddr: {Balance: testBalance}},
 		ExtraData:  []byte("test genesis"),
 		Timestamp:  9000,
@@ -65,13 +63,11 @@ func generatePreMergeChain(n int) (*core.Genesis, []*types.Block) {
 	generate := func(i int, g *core.BlockGen) {
 		g.OffsetTime(5)
 		g.SetExtra([]byte("test"))
-		tx, _ := types.SignTx(types.NewTransaction(testNonce, common.HexToAddress("0x9a9070028361F7AAbeB3f2F2Dc07F82C4a98A02a"), big.NewInt(1), params.TxGas, big.NewInt(params.InitialBaseFee*2), nil), types.LatestSigner(config), testKey)
+		tx, _ := types.SignTx(types.NewTransaction(testNonce, common.HexToAddress("0x9a9070028361F7AAbeB3f2F2Dc07F82C4a98A02a"), big.NewInt(1), params.TxGas, big.NewInt(params.InitialBaseFee*2), nil), types.LatestSigner(&config), testKey)
 		g.AddTx(tx)
 		testNonce++
 	}
-	gblock := genesis.MustCommit(db)
-	engine := ethash.NewFaker()
-	blocks, _ := core.GenerateChain(config, gblock, engine, db, n, generate)
+	_, blocks, _ := core.GenerateChainWithGenesis(genesis, ethash.NewFaker(), n, generate)
 	totalDifficulty := big.NewInt(0)
 	for _, b := range blocks {
 		totalDifficulty.Add(totalDifficulty, b.Difficulty())
diff --git a/eth/downloader/downloader_test.go b/eth/downloader/downloader_test.go
index eb72f0fc3c..36d6795e7a 100644
--- a/eth/downloader/downloader_test.go
+++ b/eth/downloader/downloader_test.go
@@ -73,8 +73,6 @@ func newTesterWithNotification(t *testing.T, success func()) *downloadTester {
 		Alloc:   core.GenesisAlloc{testAddress: {Balance: big.NewInt(1000000000000000)}},
 		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
-	gspec.MustCommit(db)
-
 	chain, err := core.NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	if err != nil {
 		panic(err)
diff --git a/eth/downloader/testchain_test.go b/eth/downloader/testchain_test.go
index 1c96681e2f..01f81a7b1c 100644
--- a/eth/downloader/testchain_test.go
+++ b/eth/downloader/testchain_test.go
@@ -38,7 +38,7 @@ var (
 	testAddress = crypto.PubkeyToAddress(testKey.PublicKey)
 	testDB      = rawdb.NewMemoryDatabase()
 
-	testGspec = core.Genesis{
+	testGspec = &core.Genesis{
 		Config:  params.TestChainConfig,
 		Alloc:   core.GenesisAlloc{testAddress: {Balance: big.NewInt(1000000000000000)}},
 		BaseFee: big.NewInt(params.InitialBaseFee),
@@ -160,7 +160,7 @@ func (tc *testChain) copy(newlen int) *testChain {
 // contains a transaction and every 5th an uncle to allow testing correct block
 // reassembly.
 func (tc *testChain) generate(n int, seed byte, parent *types.Block, heavy bool) {
-	blocks, _ := core.GenerateChain(params.TestChainConfig, parent, ethash.NewFaker(), testDB, n, func(i int, block *core.BlockGen) {
+	blocks, _ := core.GenerateChain(testGspec.Config, parent, ethash.NewFaker(), testDB, n, func(i int, block *core.BlockGen) {
 		block.SetCoinbase(common.Address{seed})
 		// If a heavy chain is requested, delay blocks to raise difficulty
 		if heavy {
@@ -217,10 +217,7 @@ func newTestBlockchain(blocks []*types.Block) *core.BlockChain {
 		if pregenerated {
 			panic("Requested chain generation outside of init")
 		}
-		db := rawdb.NewMemoryDatabase()
-		testGspec.MustCommit(db)
-
-		chain, err := core.NewBlockChain(db, nil, &testGspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+		chain, err := core.NewBlockChain(rawdb.NewMemoryDatabase(), nil, testGspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 		if err != nil {
 			panic(err)
 		}
diff --git a/eth/fetcher/block_fetcher_test.go b/eth/fetcher/block_fetcher_test.go
index bf7946952e..9e5693c02e 100644
--- a/eth/fetcher/block_fetcher_test.go
+++ b/eth/fetcher/block_fetcher_test.go
@@ -39,7 +39,8 @@ var (
 	testdb      = rawdb.NewMemoryDatabase()
 	testKey, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 	testAddress = crypto.PubkeyToAddress(testKey.PublicKey)
-	gspec       = core.Genesis{
+	gspec       = &core.Genesis{
+		Config:  params.TestChainConfig,
 		Alloc:   core.GenesisAlloc{testAddress: {Balance: big.NewInt(1000000000000000)}},
 		BaseFee: big.NewInt(params.InitialBaseFee),
 	}
@@ -52,7 +53,7 @@ var (
 // contains a transaction and every 5th an uncle to allow testing correct block
 // reassembly.
 func makeChain(n int, seed byte, parent *types.Block) ([]common.Hash, map[common.Hash]*types.Block) {
-	blocks, _ := core.GenerateChain(params.TestChainConfig, parent, ethash.NewFaker(), testdb, n, func(i int, block *core.BlockGen) {
+	blocks, _ := core.GenerateChain(gspec.Config, parent, ethash.NewFaker(), testdb, n, func(i int, block *core.BlockGen) {
 		block.SetCoinbase(common.Address{seed})
 
 		// If the block number is multiple of 3, send a bonus transaction to the miner
diff --git a/eth/filters/filter_system_test.go b/eth/filters/filter_system_test.go
index 51bda29b42..73a4ab2d4f 100644
--- a/eth/filters/filter_system_test.go
+++ b/eth/filters/filter_system_test.go
@@ -165,9 +165,12 @@ func TestBlockSubscription(t *testing.T) {
 		db           = rawdb.NewMemoryDatabase()
 		backend, sys = newTestFilterSystem(t, db, Config{})
 		api          = NewFilterAPI(sys, false)
-		genesis      = (&core.Genesis{BaseFee: big.NewInt(params.InitialBaseFee)}).MustCommit(db)
-		chain, _     = core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 10, func(i int, gen *core.BlockGen) {})
-		chainEvents  = []core.ChainEvent{}
+		genesis      = &core.Genesis{
+			Config:  params.TestChainConfig,
+			BaseFee: big.NewInt(params.InitialBaseFee),
+		}
+		_, chain, _ = core.GenerateChainWithGenesis(genesis, ethash.NewFaker(), 10, func(i int, gen *core.BlockGen) {})
+		chainEvents = []core.ChainEvent{}
 	)
 
 	for _, blk := range chain {
diff --git a/eth/filters/filter_test.go b/eth/filters/filter_test.go
index 2c1f7cadf4..39ed46cec7 100644
--- a/eth/filters/filter_test.go
+++ b/eth/filters/filter_test.go
@@ -40,10 +40,8 @@ func makeReceipt(addr common.Address) *types.Receipt {
 }
 
 func BenchmarkFilters(b *testing.B) {
-	dir := b.TempDir()
-
 	var (
-		db, _   = rawdb.NewLevelDBDatabase(dir, 0, 0, "", false)
+		db, _   = rawdb.NewLevelDBDatabase(b.TempDir(), 0, 0, "", false)
 		_, sys  = newTestFilterSystem(b, db, Config{})
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
@@ -51,17 +49,14 @@ func BenchmarkFilters(b *testing.B) {
 		addr3   = common.BytesToAddress([]byte("ethereum"))
 		addr4   = common.BytesToAddress([]byte("random addresses please"))
 
-		gspec = core.Genesis{
+		gspec = &core.Genesis{
 			Alloc:   core.GenesisAlloc{addr1: {Balance: big.NewInt(1000000)}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.ToBlock()
 	)
 	defer db.Close()
 
-	gspec.MustCommit(db)
-
-	chain, receipts := core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 100010, func(i int, gen *core.BlockGen) {
+	_, chain, receipts := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), 100010, func(i int, gen *core.BlockGen) {
 		switch i {
 		case 2403:
 			receipt := makeReceipt(addr1)
@@ -100,10 +95,8 @@ func BenchmarkFilters(b *testing.B) {
 }
 
 func TestFilters(t *testing.T) {
-	dir := t.TempDir()
-
 	var (
-		db, _   = rawdb.NewLevelDBDatabase(dir, 0, 0, "", false)
+		db, _   = rawdb.NewLevelDBDatabase(t.TempDir(), 0, 0, "", false)
 		_, sys  = newTestFilterSystem(t, db, Config{})
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr    = crypto.PubkeyToAddress(key1.PublicKey)
@@ -113,17 +106,15 @@ func TestFilters(t *testing.T) {
 		hash3 = common.BytesToHash([]byte("topic3"))
 		hash4 = common.BytesToHash([]byte("topic4"))
 
-		gspec = core.Genesis{
+		gspec = &core.Genesis{
+			Config:  params.TestChainConfig,
 			Alloc:   core.GenesisAlloc{addr: {Balance: big.NewInt(1000000)}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.ToBlock()
 	)
 	defer db.Close()
 
-	gspec.MustCommit(db)
-
-	chain, receipts := core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 1000, func(i int, gen *core.BlockGen) {
+	_, chain, receipts := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), 1000, func(i int, gen *core.BlockGen) {
 		switch i {
 		case 1:
 			receipt := types.NewReceipt(nil, false, 0)
@@ -168,6 +159,10 @@ func TestFilters(t *testing.T) {
 			gen.AddUncheckedTx(types.NewTransaction(999, common.HexToAddress("0x999"), big.NewInt(999), 999, gen.BaseFee(), nil))
 		}
 	})
+	// The test txs are not properly signed, can't simply create a chain
+	// and then import blocks. TODO(rjl493456442) try to get rid of the
+	// manual database writes.
+	gspec.MustCommit(db)
 	for i, block := range chain {
 		rawdb.WriteBlock(db, block)
 		rawdb.WriteCanonicalHash(db, block.Hash(), block.NumberU64())
diff --git a/eth/gasprice/gasprice_test.go b/eth/gasprice/gasprice_test.go
index 5830312fd1..a4399661fc 100644
--- a/eth/gasprice/gasprice_test.go
+++ b/eth/gasprice/gasprice_test.go
@@ -129,11 +129,9 @@ func newTestBackend(t *testing.T, londonBlock *big.Int, pending bool) *testBacke
 	config.GrayGlacierBlock = londonBlock
 	config.TerminalTotalDifficulty = common.Big0
 	engine := ethash.NewFaker()
-	db := rawdb.NewMemoryDatabase()
-	genesis := gspec.MustCommit(db)
 
 	// Generate testing blocks
-	blocks, _ := core.GenerateChain(gspec.Config, genesis, engine, db, testHead+1, func(i int, b *core.BlockGen) {
+	_, blocks, _ := core.GenerateChainWithGenesis(gspec, engine, testHead+1, func(i int, b *core.BlockGen) {
 		b.SetCoinbase(common.Address{1})
 
 		var txdata types.TxData
@@ -160,9 +158,7 @@ func newTestBackend(t *testing.T, londonBlock *big.Int, pending bool) *testBacke
 		b.AddTx(types.MustSignNewTx(key, signer, txdata))
 	})
 	// Construct testing chain
-	diskdb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(diskdb)
-	chain, err := core.NewBlockChain(diskdb, &core.CacheConfig{TrieCleanNoPrefetch: true}, gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, err := core.NewBlockChain(rawdb.NewMemoryDatabase(), &core.CacheConfig{TrieCleanNoPrefetch: true}, gspec, nil, engine, vm.Config{}, nil, nil)
 	if err != nil {
 		t.Fatalf("Failed to create local chain, %v", err)
 	}
diff --git a/eth/handler_eth_test.go b/eth/handler_eth_test.go
index 9c2fcd36f7..9f0c36f950 100644
--- a/eth/handler_eth_test.go
+++ b/eth/handler_eth_test.go
@@ -102,14 +102,11 @@ func testForkIDSplit(t *testing.T, protocol uint) {
 		gspecNoFork  = &core.Genesis{Config: configNoFork}
 		gspecProFork = &core.Genesis{Config: configProFork}
 
-		genesisNoFork  = gspecNoFork.MustCommit(dbNoFork)
-		genesisProFork = gspecProFork.MustCommit(dbProFork)
-
 		chainNoFork, _  = core.NewBlockChain(dbNoFork, nil, gspecNoFork, nil, engine, vm.Config{}, nil, nil)
 		chainProFork, _ = core.NewBlockChain(dbProFork, nil, gspecProFork, nil, engine, vm.Config{}, nil, nil)
 
-		blocksNoFork, _  = core.GenerateChain(configNoFork, genesisNoFork, engine, dbNoFork, 2, nil)
-		blocksProFork, _ = core.GenerateChain(configProFork, genesisProFork, engine, dbProFork, 2, nil)
+		_, blocksNoFork, _  = core.GenerateChainWithGenesis(gspecNoFork, engine, 2, nil)
+		_, blocksProFork, _ = core.GenerateChainWithGenesis(gspecProFork, engine, 2, nil)
 
 		ethNoFork, _ = newHandler(&handlerConfig{
 			Database:   dbNoFork,
diff --git a/eth/handler_test.go b/eth/handler_test.go
index 044130f40f..8939e53a95 100644
--- a/eth/handler_test.go
+++ b/eth/handler_test.go
@@ -137,11 +137,9 @@ func newTestHandlerWithBlocks(blocks int) *testHandler {
 		Config: params.TestChainConfig,
 		Alloc:  core.GenesisAlloc{testAddr: {Balance: big.NewInt(1000000)}},
 	}
-	gspec.MustCommit(db)
-
 	chain, _ := core.NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 
-	bs, _ := core.GenerateChain(params.TestChainConfig, chain.Genesis(), ethash.NewFaker(), db, blocks, nil)
+	_, bs, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), blocks, nil)
 	if _, err := chain.InsertChain(bs); err != nil {
 		panic(err)
 	}
diff --git a/eth/protocols/eth/handler_test.go b/eth/protocols/eth/handler_test.go
index ea2edc4a91..ef534ba376 100644
--- a/eth/protocols/eth/handler_test.go
+++ b/eth/protocols/eth/handler_test.go
@@ -67,14 +67,15 @@ func newTestBackendWithGenerator(blocks int, generator func(int, *core.BlockGen)
 		Config: params.TestChainConfig,
 		Alloc:  core.GenesisAlloc{testAddr: {Balance: big.NewInt(100_000_000_000_000_000)}},
 	}
-	gspec.MustCommit(db)
-
 	chain, _ := core.NewBlockChain(db, nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 
-	bs, _ := core.GenerateChain(params.TestChainConfig, chain.Genesis(), ethash.NewFaker(), db, blocks, generator)
+	_, bs, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), blocks, generator)
 	if _, err := chain.InsertChain(bs); err != nil {
 		panic(err)
 	}
+	for _, block := range bs {
+		chain.StateCache().TrieDB().Commit(block.Root(), false, nil)
+	}
 	txconfig := core.DefaultTxPoolConfig
 	txconfig.Journal = "" // Don't litter the disk with test journals
 
diff --git a/eth/tracers/api_test.go b/eth/tracers/api_test.go
index b75b679359..40d860b857 100644
--- a/eth/tracers/api_test.go
+++ b/eth/tracers/api_test.go
@@ -61,20 +61,14 @@ type testBackend struct {
 
 func newTestBackend(t *testing.T, n int, gspec *core.Genesis, generator func(i int, b *core.BlockGen)) *testBackend {
 	backend := &testBackend{
-		chainConfig: params.TestChainConfig,
+		chainConfig: gspec.Config,
 		engine:      ethash.NewFaker(),
 		chaindb:     rawdb.NewMemoryDatabase(),
 	}
 	// Generate blocks for testing
-	gspec.Config = backend.chainConfig
-	var (
-		gendb   = rawdb.NewMemoryDatabase()
-		genesis = gspec.MustCommit(gendb)
-	)
-	blocks, _ := core.GenerateChain(backend.chainConfig, genesis, backend.engine, gendb, n, generator)
+	_, blocks, _ := core.GenerateChainWithGenesis(gspec, backend.engine, n, generator)
 
 	// Import the canonical chain
-	gspec.MustCommit(backend.chaindb)
 	cacheConfig := &core.CacheConfig{
 		TrieCleanLimit:    256,
 		TrieDirtyLimit:    256,
diff --git a/ethclient/ethclient_test.go b/ethclient/ethclient_test.go
index f2f4a5765d..67b1fde756 100644
--- a/ethclient/ethclient_test.go
+++ b/ethclient/ethclient_test.go
@@ -30,7 +30,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
@@ -238,7 +237,6 @@ func newTestBackend(t *testing.T) (*node.Node, []*types.Block) {
 }
 
 func generateTestChain() []*types.Block {
-	db := rawdb.NewMemoryDatabase()
 	generate := func(i int, g *core.BlockGen) {
 		g.OffsetTime(5)
 		g.SetExtra([]byte("test"))
@@ -248,11 +246,8 @@ func generateTestChain() []*types.Block {
 			g.AddTx(testTx2)
 		}
 	}
-	gblock := genesis.MustCommit(db)
-	engine := ethash.NewFaker()
-	blocks, _ := core.GenerateChain(genesis.Config, gblock, engine, db, 2, generate)
-	blocks = append([]*types.Block{gblock}, blocks...)
-	return blocks
+	_, blocks, _ := core.GenerateChainWithGenesis(genesis, ethash.NewFaker(), 2, generate)
+	return append([]*types.Block{genesis.ToBlock()}, blocks...)
 }
 
 func TestEthClient(t *testing.T) {
diff --git a/ethclient/gethclient/gethclient_test.go b/ethclient/gethclient/gethclient_test.go
index a0f4eaaf5d..e77c6015a2 100644
--- a/ethclient/gethclient/gethclient_test.go
+++ b/ethclient/gethclient/gethclient_test.go
@@ -26,7 +26,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
@@ -78,10 +77,8 @@ func newTestBackend(t *testing.T) (*node.Node, []*types.Block) {
 }
 
 func generateTestChain() (*core.Genesis, []*types.Block) {
-	db := rawdb.NewMemoryDatabase()
-	config := params.AllEthashProtocolChanges
 	genesis := &core.Genesis{
-		Config:    config,
+		Config:    params.AllEthashProtocolChanges,
 		Alloc:     core.GenesisAlloc{testAddr: {Balance: testBalance, Storage: map[common.Hash]common.Hash{testSlot: testValue}}},
 		ExtraData: []byte("test genesis"),
 		Timestamp: 9000,
@@ -90,10 +87,8 @@ func generateTestChain() (*core.Genesis, []*types.Block) {
 		g.OffsetTime(5)
 		g.SetExtra([]byte("test"))
 	}
-	gblock := genesis.MustCommit(db)
-	engine := ethash.NewFaker()
-	blocks, _ := core.GenerateChain(config, gblock, engine, db, 1, generate)
-	blocks = append([]*types.Block{gblock}, blocks...)
+	_, blocks, _ := core.GenerateChainWithGenesis(genesis, ethash.NewFaker(), 1, generate)
+	blocks = append([]*types.Block{genesis.ToBlock()}, blocks...)
 	return genesis, blocks
 }
 
diff --git a/les/catalyst/api_test.go b/les/catalyst/api_test.go
index 26c49d6ef9..6d0eedeccb 100644
--- a/les/catalyst/api_test.go
+++ b/les/catalyst/api_test.go
@@ -24,7 +24,6 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/beacon"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth/downloader"
@@ -46,18 +45,15 @@ var (
 )
 
 func generatePreMergeChain(n int) (*core.Genesis, []*types.Header, []*types.Block) {
-	db := rawdb.NewMemoryDatabase()
-	config := params.AllEthashProtocolChanges
+	config := *params.AllEthashProtocolChanges
 	genesis := &core.Genesis{
-		Config:    config,
+		Config:    &config,
 		Alloc:     core.GenesisAlloc{testAddr: {Balance: testBalance}},
 		ExtraData: []byte("test genesis"),
 		Timestamp: 9000,
 		BaseFee:   big.NewInt(params.InitialBaseFee),
 	}
-	gblock := genesis.MustCommit(db)
-	engine := ethash.NewFaker()
-	blocks, _ := core.GenerateChain(config, gblock, engine, db, n, nil)
+	_, blocks, _ := core.GenerateChainWithGenesis(genesis, ethash.NewFaker(), n, nil)
 	totalDifficulty := big.NewInt(0)
 
 	var headers []*types.Header
diff --git a/les/odr_test.go b/les/odr_test.go
index 24b8e2ae31..48fd9f95e3 100644
--- a/les/odr_test.go
+++ b/les/odr_test.go
@@ -129,7 +129,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, config *params.Chai
 		data[35] = byte(i)
 		if bc != nil {
 			header := bc.GetHeaderByHash(bhash)
-			statedb, err := state.New(header.Root, state.NewDatabase(db), nil)
+			statedb, err := state.New(header.Root, bc.StateCache(), nil)
 
 			if err == nil {
 				from := statedb.GetOrNewStateObject(bankAddr)
diff --git a/light/odr_test.go b/light/odr_test.go
index d08963af66..7f56705875 100644
--- a/light/odr_test.go
+++ b/light/odr_test.go
@@ -36,7 +36,6 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
-	"github.com/ethereum/go-ethereum/trie"
 )
 
 var (
@@ -57,6 +56,7 @@ type testOdr struct {
 	OdrBackend
 	indexerConfig *IndexerConfig
 	sdb, ldb      ethdb.Database
+	serverState   state.Database
 	disable       bool
 }
 
@@ -82,7 +82,18 @@ func (odr *testOdr) Retrieve(ctx context.Context, req OdrRequest) error {
 			req.Receipts = rawdb.ReadRawReceipts(odr.sdb, req.Hash, *number)
 		}
 	case *TrieRequest:
-		t, _ := trie.New(common.BytesToHash(req.Id.AccKey), req.Id.Root, trie.NewDatabase(odr.sdb))
+		var (
+			err error
+			t   state.Trie
+		)
+		if len(req.Id.AccKey) > 0 {
+			t, err = odr.serverState.OpenStorageTrie(common.BytesToHash(req.Id.AccKey), req.Id.Root)
+		} else {
+			t, err = odr.serverState.OpenTrie(req.Id.Root)
+		}
+		if err != nil {
+			panic(err)
+		}
 		nodes := NewNodeSet()
 		t.Prove(req.Key, 0, nodes)
 		req.Proof = nodes
@@ -149,7 +160,7 @@ func odrAccounts(ctx context.Context, db ethdb.Database, bc *core.BlockChain, lc
 		st = NewState(ctx, header, lc.Odr())
 	} else {
 		header := bc.GetHeaderByHash(bhash)
-		st, _ = state.New(header.Root, state.NewDatabase(db), nil)
+		st, _ = state.New(header.Root, bc.StateCache(), nil)
 	}
 
 	var res []byte
@@ -189,7 +200,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, bc *core.BlockChain
 		} else {
 			chain = bc
 			header = bc.GetHeaderByHash(bhash)
-			st, _ = state.New(header.Root, state.NewDatabase(db), nil)
+			st, _ = state.New(header.Root, bc.StateCache(), nil)
 		}
 
 		// Perform read-only call.
@@ -258,18 +269,17 @@ func testChainOdr(t *testing.T, protocol int, fn odrTestFn) {
 			Alloc:   core.GenesisAlloc{testBankAddress: {Balance: testBankFunds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(sdb)
 	)
-	gspec.MustCommit(ldb)
 	// Assemble the test environment
 	blockchain, _ := core.NewBlockChain(sdb, nil, gspec, nil, ethash.NewFullFaker(), vm.Config{}, nil, nil)
-	gchain, _ := core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), sdb, 4, testChainGen)
+	_, gchain, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), 4, testChainGen)
 	if _, err := blockchain.InsertChain(gchain); err != nil {
 		t.Fatal(err)
 	}
 
-	odr := &testOdr{sdb: sdb, ldb: ldb, indexerConfig: TestClientIndexerConfig}
-	lightchain, err := NewLightChain(odr, params.TestChainConfig, ethash.NewFullFaker(), nil)
+	gspec.MustCommit(ldb)
+	odr := &testOdr{sdb: sdb, ldb: ldb, serverState: blockchain.StateCache(), indexerConfig: TestClientIndexerConfig}
+	lightchain, err := NewLightChain(odr, gspec.Config, ethash.NewFullFaker(), nil)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/light/trie_test.go b/light/trie_test.go
index 581469c41f..0ab3eb02a0 100644
--- a/light/trie_test.go
+++ b/light/trie_test.go
@@ -42,20 +42,19 @@ func TestNodeIterator(t *testing.T) {
 			Alloc:   core.GenesisAlloc{testBankAddress: {Balance: testBankFunds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(fulldb)
 	)
-	gspec.MustCommit(lightdb)
 	blockchain, _ := core.NewBlockChain(fulldb, nil, gspec, nil, ethash.NewFullFaker(), vm.Config{}, nil, nil)
-	gchain, _ := core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), fulldb, 4, testChainGen)
+	_, gchain, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), 4, testChainGen)
 	if _, err := blockchain.InsertChain(gchain); err != nil {
 		panic(err)
 	}
 
+	gspec.MustCommit(lightdb)
 	ctx := context.Background()
-	odr := &testOdr{sdb: fulldb, ldb: lightdb, indexerConfig: TestClientIndexerConfig}
+	odr := &testOdr{sdb: fulldb, ldb: lightdb, serverState: blockchain.StateCache(), indexerConfig: TestClientIndexerConfig}
 	head := blockchain.CurrentHeader()
 	lightTrie, _ := NewStateDatabase(ctx, head, odr).OpenTrie(head.Root)
-	fullTrie, _ := state.NewDatabase(fulldb).OpenTrie(head.Root)
+	fullTrie, _ := blockchain.StateCache().OpenTrie(head.Root)
 	if err := diffTries(fullTrie, lightTrie); err != nil {
 		t.Fatal(err)
 	}
diff --git a/light/txpool_test.go b/light/txpool_test.go
index 78cac513cb..53732acfa8 100644
--- a/light/txpool_test.go
+++ b/light/txpool_test.go
@@ -88,17 +88,16 @@ func TestTxPool(t *testing.T) {
 			Alloc:   core.GenesisAlloc{testBankAddress: {Balance: testBankFunds}},
 			BaseFee: big.NewInt(params.InitialBaseFee),
 		}
-		genesis = gspec.MustCommit(sdb)
 	)
-	gspec.MustCommit(ldb)
 	// Assemble the test environment
 	blockchain, _ := core.NewBlockChain(sdb, nil, gspec, nil, ethash.NewFullFaker(), vm.Config{}, nil, nil)
-	gchain, _ := core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), sdb, poolTestBlocks, txPoolTestChainGen)
+	_, gchain, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), poolTestBlocks, txPoolTestChainGen)
 	if _, err := blockchain.InsertChain(gchain); err != nil {
 		panic(err)
 	}
 
-	odr := &testOdr{sdb: sdb, ldb: ldb, indexerConfig: TestClientIndexerConfig}
+	gspec.MustCommit(ldb)
+	odr := &testOdr{sdb: sdb, ldb: ldb, serverState: blockchain.StateCache(), indexerConfig: TestClientIndexerConfig}
 	relay := &testTxRelay{
 		send:    make(chan int, 1),
 		discard: make(chan int, 1),
diff --git a/miner/worker_test.go b/miner/worker_test.go
index 3c70b4baaf..2f1939f759 100644
--- a/miner/worker_test.go
+++ b/miner/worker_test.go
@@ -118,11 +118,10 @@ type testWorkerBackend struct {
 }
 
 func newTestWorkerBackend(t *testing.T, chainConfig *params.ChainConfig, engine consensus.Engine, db ethdb.Database, n int) *testWorkerBackend {
-	var gspec = core.Genesis{
+	var gspec = &core.Genesis{
 		Config: chainConfig,
 		Alloc:  core.GenesisAlloc{testBankAddress: {Balance: testBankFunds}},
 	}
-
 	switch e := engine.(type) {
 	case *clique.Clique:
 		gspec.ExtraData = make([]byte, 32+common.AddressLength+crypto.SignatureLength)
@@ -134,34 +133,35 @@ func newTestWorkerBackend(t *testing.T, chainConfig *params.ChainConfig, engine
 	default:
 		t.Fatalf("unexpected consensus engine type: %T", engine)
 	}
-	genesis := gspec.MustCommit(db)
-
-	chain, _ := core.NewBlockChain(db, &core.CacheConfig{TrieDirtyDisabled: true}, &gspec, nil, engine, vm.Config{}, nil, nil)
+	chain, _ := core.NewBlockChain(db, &core.CacheConfig{TrieDirtyDisabled: true}, gspec, nil, engine, vm.Config{}, nil, nil)
 	txpool := core.NewTxPool(testTxPoolConfig, chainConfig, chain)
 
 	// Generate a small n-block chain and an uncle block for it
+	var uncle *types.Block
 	if n > 0 {
-		blocks, _ := core.GenerateChain(chainConfig, genesis, engine, db, n, func(i int, gen *core.BlockGen) {
+		genDb, blocks, _ := core.GenerateChainWithGenesis(gspec, engine, n, func(i int, gen *core.BlockGen) {
 			gen.SetCoinbase(testBankAddress)
 		})
 		if _, err := chain.InsertChain(blocks); err != nil {
 			t.Fatalf("failed to insert origin chain: %v", err)
 		}
+		parent := chain.GetBlockByHash(chain.CurrentBlock().ParentHash())
+		blocks, _ = core.GenerateChain(chainConfig, parent, engine, genDb, 1, func(i int, gen *core.BlockGen) {
+			gen.SetCoinbase(testUserAddress)
+		})
+		uncle = blocks[0]
+	} else {
+		_, blocks, _ := core.GenerateChainWithGenesis(gspec, engine, 1, func(i int, gen *core.BlockGen) {
+			gen.SetCoinbase(testUserAddress)
+		})
+		uncle = blocks[0]
 	}
-	parent := genesis
-	if n > 0 {
-		parent = chain.GetBlockByHash(chain.CurrentBlock().ParentHash())
-	}
-	blocks, _ := core.GenerateChain(chainConfig, parent, engine, db, 1, func(i int, gen *core.BlockGen) {
-		gen.SetCoinbase(testUserAddress)
-	})
-
 	return &testWorkerBackend{
 		db:         db,
 		chain:      chain,
 		txPool:     txpool,
-		genesis:    &gspec,
-		uncleBlock: blocks[0],
+		genesis:    gspec,
+		uncleBlock: uncle,
 	}
 }
 
@@ -217,26 +217,22 @@ func TestGenerateBlockAndImportClique(t *testing.T) {
 func testGenerateBlockAndImport(t *testing.T, isClique bool) {
 	var (
 		engine      consensus.Engine
-		chainConfig *params.ChainConfig
+		chainConfig params.ChainConfig
 		db          = rawdb.NewMemoryDatabase()
 	)
 	if isClique {
-		chainConfig = params.AllCliqueProtocolChanges
+		chainConfig = *params.AllCliqueProtocolChanges
 		chainConfig.Clique = &params.CliqueConfig{Period: 1, Epoch: 30000}
 		engine = clique.New(chainConfig.Clique, db)
 	} else {
-		chainConfig = params.AllEthashProtocolChanges
+		chainConfig = *params.AllEthashProtocolChanges
 		engine = ethash.NewFaker()
 	}
-
-	chainConfig.LondonBlock = big.NewInt(0)
-	w, b := newTestWorker(t, chainConfig, engine, db, 0)
+	w, b := newTestWorker(t, &chainConfig, engine, db, 0)
 	defer w.close()
 
 	// This test chain imports the mined blocks.
-	db2 := rawdb.NewMemoryDatabase()
-	b.genesis.MustCommit(db2)
-	chain, _ := core.NewBlockChain(db2, nil, b.genesis, nil, engine, vm.Config{}, nil, nil)
+	chain, _ := core.NewBlockChain(rawdb.NewMemoryDatabase(), nil, b.genesis, nil, engine, vm.Config{}, nil, nil)
 	defer chain.Stop()
 
 	// Ignore empty commit here for less noise.
diff --git a/tests/fuzzers/les/les-fuzzer.go b/tests/fuzzers/les/les-fuzzer.go
index bb50da2bd8..d3a25a31c0 100644
--- a/tests/fuzzers/les/les-fuzzer.go
+++ b/tests/fuzzers/les/les-fuzzer.go
@@ -54,15 +54,13 @@ var (
 )
 
 func makechain() (bc *core.BlockChain, addrHashes, txHashes []common.Hash) {
-	db := rawdb.NewMemoryDatabase()
-	gspec := core.Genesis{
+	gspec := &core.Genesis{
 		Config:   params.TestChainConfig,
 		Alloc:    core.GenesisAlloc{bankAddr: {Balance: bankFunds}},
 		GasLimit: 100000000,
 	}
-	genesis := gspec.MustCommit(db)
 	signer := types.HomesteadSigner{}
-	blocks, _ := core.GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, testChainLen,
+	_, blocks, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), testChainLen,
 		func(i int, gen *core.BlockGen) {
 			var (
 				tx   *types.Transaction
@@ -80,7 +78,7 @@ func makechain() (bc *core.BlockChain, addrHashes, txHashes []common.Hash) {
 			addrHashes = append(addrHashes, crypto.Keccak256Hash(addr[:]))
 			txHashes = append(txHashes, tx.Hash())
 		})
-	bc, _ = core.NewBlockChain(db, nil, &gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	bc, _ = core.NewBlockChain(rawdb.NewMemoryDatabase(), nil, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	if _, err := bc.InsertChain(blocks); err != nil {
 		panic(err)
 	}
diff --git a/tests/fuzzers/snap/fuzz_handler.go b/tests/fuzzers/snap/fuzz_handler.go
index 6c370b043e..2e5dcd6e29 100644
--- a/tests/fuzzers/snap/fuzz_handler.go
+++ b/tests/fuzzers/snap/fuzz_handler.go
@@ -39,7 +39,6 @@ import (
 var trieRoot common.Hash
 
 func getChain() *core.BlockChain {
-	db := rawdb.NewMemoryDatabase()
 	ga := make(core.GenesisAlloc, 1000)
 	var a = make([]byte, 20)
 	var mkStorage = func(k, v int) (common.Hash, common.Hash) {
@@ -66,9 +65,7 @@ func getChain() *core.BlockChain {
 		Config: params.TestChainConfig,
 		Alloc:  ga,
 	}
-	genesis := gspec.MustCommit(db)
-	blocks, _ := core.GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, 2,
-		func(i int, gen *core.BlockGen) {})
+	_, blocks, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), 2, func(i int, gen *core.BlockGen) {})
 	cacheConf := &core.CacheConfig{
 		TrieCleanLimit:      0,
 		TrieDirtyLimit:      0,
@@ -79,7 +76,7 @@ func getChain() *core.BlockChain {
 		SnapshotWait:        true,
 	}
 	trieRoot = blocks[len(blocks)-1].Root()
-	bc, _ := core.NewBlockChain(db, cacheConf, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	bc, _ := core.NewBlockChain(rawdb.NewMemoryDatabase(), cacheConf, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
 	if _, err := bc.InsertChain(blocks); err != nil {
 		panic(err)
 	}