all: remove TerminalTotalDifficultyPassed (#30609)

rebased https://github.com/ethereum/go-ethereum/pull/29766 . The
downstream branch appears to have been deleted and I don't have perms to
push to that fork.

`TerminalTotalDifficultyPassed` is removed. `TerminalTotalDifficulty`
must now be non-nil, and it is expected that networks are already
merged: we can only import PoW/Clique chains, not produce blocks on
them.

---------

Co-authored-by: stevemilk <wangpeculiar@gmail.com>

cmd/devp2p/internal/ethtest/testdata/genesis.json

@@ -18,7 +18,6 @@
     "shanghaiTime": 780,
     "cancunTime": 840,
     "terminalTotalDifficulty": 9454784,
-    "terminalTotalDifficultyPassed": true,
     "ethash": {}
   },
   "nonce": "0x0",

cmd/geth/genesis_test.go

@@ -29,7 +29,7 @@ var customGenesisTests = []struct {
 	query   string
 	result  string
 }{
-	// Genesis file with an empty chain configuration (ensure missing fields work)
+	// Genesis file with a mostly-empty chain configuration (ensure missing fields work)
 	{
 		genesis: `{
 			"alloc"      : {},
@@ -41,8 +41,8 @@ var customGenesisTests = []struct {
 			"mixhash"    : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"timestamp"  : "0x00",
-			"config"     : {
+			"config": {
-				"terminalTotalDifficultyPassed": true
+				"terminalTotalDifficulty": 0
 			}
 		}`,
 		query:  "eth.getBlock(0).nonce",
@@ -64,7 +64,7 @@ var customGenesisTests = []struct {
 				"homesteadBlock"                : 42,
 				"daoForkBlock"                  : 141,
 				"daoForkSupport"                : true,
-				"terminalTotalDifficultyPassed" : true
+				"terminalTotalDifficulty": 0
 			}
 		}`,
 		query:  "eth.getBlock(0).nonce",
@@ -114,8 +114,8 @@ func TestCustomBackend(t *testing.T) {
 			"mixhash"    : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"timestamp"  : "0x00",
-			"config"     : {
+			"config": {
-				"terminalTotalDifficultyPassed": true
+				"terminalTotalDifficulty": 0
 			}
 		}`
 	type backendTest struct {

cmd/geth/testdata/clique.json

@@ -8,7 +8,7 @@
     "byzantiumBlock": 0,
     "constantinopleBlock": 0,
     "petersburgBlock": 0,
-    "terminalTotalDifficultyPassed": true,
+    "terminalTotalDifficulty": 0,
     "clique": {
       "period": 5,
       "epoch": 30000

cmd/utils/flags.go

@@ -1867,9 +1867,6 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 				if err != nil {
 					Fatalf("Could not read genesis from database: %v", err)
 				}
-				if !genesis.Config.TerminalTotalDifficultyPassed {
-					Fatalf("Bad developer-mode genesis configuration: terminalTotalDifficultyPassed must be true")
-				}
 				if genesis.Config.TerminalTotalDifficulty == nil {
 					Fatalf("Bad developer-mode genesis configuration: terminalTotalDifficulty must be specified")
 				} else if genesis.Config.TerminalTotalDifficulty.Cmp(big.NewInt(0)) != 0 {

consensus/beacon/consensus.go

@@ -116,9 +116,6 @@ func errOut(n int, err error) chan error {
 func (beacon *Beacon) splitHeaders(chain consensus.ChainHeaderReader, headers []*types.Header) ([]*types.Header, []*types.Header, error) {
 	// TTD is not defined yet, all headers should be in legacy format.
 	ttd := chain.Config().TerminalTotalDifficulty
-	if ttd == nil {
-		return headers, nil, nil
-	}
 	ptd := chain.GetTd(headers[0].ParentHash, headers[0].Number.Uint64()-1)
 	if ptd == nil {
 		return nil, nil, consensus.ErrUnknownAncestor
@@ -495,9 +492,6 @@ func (beacon *Beacon) SetThreads(threads int) {
 // It depends on the parentHash already being stored in the database.
 // If the parentHash is not stored in the database a UnknownAncestor error is returned.
 func IsTTDReached(chain consensus.ChainHeaderReader, parentHash common.Hash, parentNumber uint64) (bool, error) {
-	if chain.Config().TerminalTotalDifficulty == nil {
-		return false, nil
-	}
 	td := chain.GetTd(parentHash, parentNumber)
 	if td == nil {
 		return false, consensus.ErrUnknownAncestor

core/block_validator_test.go

@@ -113,8 +113,12 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 		}
 		copy(gspec.ExtraData[32:], addr[:])
 
+		// chain_maker has no blockchain to retrieve the TTD from, setting to nil
+		// is a hack to signal it to generate pre-merge blocks
+		gspec.Config.TerminalTotalDifficulty = nil
 		td := 0
 		genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, 8, nil)
+
 		for i, block := range blocks {
 			header := block.Header()
 			if i > 0 {
@@ -145,7 +149,6 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 		}
 		preBlocks = blocks
 		gspec.Config.TerminalTotalDifficulty = big.NewInt(int64(td))
-		t.Logf("Set ttd to %v\n", gspec.Config.TerminalTotalDifficulty)
 		postBlocks, _ = GenerateChain(gspec.Config, preBlocks[len(preBlocks)-1], engine, genDb, 8, func(i int, gen *BlockGen) {
 			gen.SetPoS()
 		})

core/blockchain_test.go

@@ -4092,7 +4092,6 @@ func TestEIP3651(t *testing.T) {
 	gspec.Config.BerlinBlock = common.Big0
 	gspec.Config.LondonBlock = common.Big0
 	gspec.Config.TerminalTotalDifficulty = common.Big0
-	gspec.Config.TerminalTotalDifficultyPassed = true
 	gspec.Config.ShanghaiTime = u64(0)
 	signer := types.LatestSigner(gspec.Config)
 

core/chain_makers_test.go

@@ -57,7 +57,6 @@ func TestGeneratePOSChain(t *testing.T) {
 		db    = rawdb.NewMemoryDatabase()
 	)
 
-	config.TerminalTotalDifficultyPassed = true
 	config.TerminalTotalDifficulty = common.Big0
 	config.ShanghaiTime = u64(0)
 	config.CancunTime = u64(0)

core/forkid/forkid_test.go

@@ -393,7 +393,6 @@ func TestTimeBasedForkInGenesis(t *testing.T) {
 				BerlinBlock:             big.NewInt(0),
 				LondonBlock:             big.NewInt(0),
 				TerminalTotalDifficulty: big.NewInt(0),
-				TerminalTotalDifficultyPassed: true,
 				MergeNetsplitBlock:      big.NewInt(0),
 				ShanghaiTime:            &shanghai,
 				CancunTime:              &cancun,

core/genesis_test.go

@@ -279,7 +279,6 @@ func TestVerkleGenesisCommit(t *testing.T) {
 		PragueTime:              &verkleTime,
 		VerkleTime:              &verkleTime,
 		TerminalTotalDifficulty: big.NewInt(0),
-		TerminalTotalDifficultyPassed: true,
 		Ethash:                  nil,
 		Clique:                  nil,
 	}

core/state_processor_test.go

@@ -65,7 +65,6 @@ func TestStateProcessorErrors(t *testing.T) {
 			LondonBlock:             big.NewInt(0),
 			Ethash:                  new(params.EthashConfig),
 			TerminalTotalDifficulty: big.NewInt(0),
-			TerminalTotalDifficultyPassed: true,
 			ShanghaiTime:            new(uint64),
 			CancunTime:              new(uint64),
 		}
@@ -257,7 +256,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				want: "could not apply tx 0 [0x6c11015985ce82db691d7b2d017acda296db88b811c3c60dc71449c76256c716]: max fee per gas less than block base fee: address 0x71562b71999873DB5b286dF957af199Ec94617F7, maxFeePerGas: 1, baseFee: 875000000",
 			},
 		} {
-			block := GenerateBadBlock(gspec.ToBlock(), beacon.New(ethash.NewFaker()), tt.txs, gspec.Config)
+			block := GenerateBadBlock(gspec.ToBlock(), beacon.New(ethash.NewFaker()), tt.txs, gspec.Config, false)
 			_, err := blockchain.InsertChain(types.Blocks{block})
 			if err == nil {
 				t.Fatal("block imported without errors")
@@ -306,7 +305,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				want: "could not apply tx 0 [0x88626ac0d53cb65308f2416103c62bb1f18b805573d4f96a3640bbbfff13c14f]: transaction type not supported",
 			},
 		} {
-			block := GenerateBadBlock(gspec.ToBlock(), ethash.NewFaker(), tt.txs, gspec.Config)
+			block := GenerateBadBlock(gspec.ToBlock(), ethash.NewFaker(), tt.txs, gspec.Config, true)
 			_, err := blockchain.InsertChain(types.Blocks{block})
 			if err == nil {
 				t.Fatal("block imported without errors")
@@ -345,7 +344,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				want: "could not apply tx 0 [0x88626ac0d53cb65308f2416103c62bb1f18b805573d4f96a3640bbbfff13c14f]: sender not an eoa: address 0x71562b71999873DB5b286dF957af199Ec94617F7, codehash: 0x9280914443471259d4570a8661015ae4a5b80186dbc619658fb494bebc3da3d1",
 			},
 		} {
-			block := GenerateBadBlock(gspec.ToBlock(), beacon.New(ethash.NewFaker()), tt.txs, gspec.Config)
+			block := GenerateBadBlock(gspec.ToBlock(), beacon.New(ethash.NewFaker()), tt.txs, gspec.Config, false)
 			_, err := blockchain.InsertChain(types.Blocks{block})
 			if err == nil {
 				t.Fatal("block imported without errors")
@@ -361,9 +360,9 @@ func TestStateProcessorErrors(t *testing.T) {
 // valid, and no proper post-state can be made. But from the perspective of the blockchain, the block is sufficiently
 // valid to be considered for import:
 // - valid pow (fake), ancestry, difficulty, gaslimit etc
-func GenerateBadBlock(parent *types.Block, engine consensus.Engine, txs types.Transactions, config *params.ChainConfig) *types.Block {
+func GenerateBadBlock(parent *types.Block, engine consensus.Engine, txs types.Transactions, config *params.ChainConfig, isPOW bool) *types.Block {
 	difficulty := big.NewInt(0)
-	if !config.TerminalTotalDifficultyPassed {
+	if isPOW {
 		fakeChainReader := newChainMaker(nil, config, engine)
 		difficulty = engine.CalcDifficulty(fakeChainReader, parent.Time()+10, &types.Header{
 			Number:     parent.Number(),
@@ -457,9 +456,6 @@ func TestProcessVerkle(t *testing.T) {
 			ShanghaiTime:            u64(0),
 			VerkleTime:              u64(0),
 			TerminalTotalDifficulty: common.Big0,
-			TerminalTotalDifficultyPassed: true,
-			// TODO uncomment when proof generation is merged
-			// ProofInBlocks:                 true,
 		}
 		signer     = types.LatestSigner(config)
 		testKey, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")

core/vm/runtime/runtime.go

@@ -78,7 +78,6 @@ func setDefaults(cfg *Config) {
 			ArrowGlacierBlock:       nil,
 			GrayGlacierBlock:        nil,
 			TerminalTotalDifficulty: big.NewInt(0),
-			TerminalTotalDifficultyPassed: true,
 			MergeNetsplitBlock:      nil,
 			ShanghaiTime:            &shanghaiTime,
 			CancunTime:              &cancunTime}
@@ -109,10 +108,7 @@ func setDefaults(cfg *Config) {
 	if cfg.BlobBaseFee == nil {
 		cfg.BlobBaseFee = big.NewInt(params.BlobTxMinBlobGasprice)
 	}
-	// Merge indicators
-	if t := cfg.ChainConfig.ShanghaiTime; cfg.ChainConfig.TerminalTotalDifficultyPassed || (t != nil && *t == 0) {
 	cfg.Random = &(common.Hash{})
-	}
 }
 
 // Execute executes the code using the input as call data during the execution.

eth/catalyst/api_test.go

@@ -66,7 +66,6 @@ func generateMergeChain(n int, merged bool) (*core.Genesis, []*types.Block) {
 	engine := consensus.Engine(beaconConsensus.New(ethash.NewFaker()))
 	if merged {
 		config.TerminalTotalDifficulty = common.Big0
-		config.TerminalTotalDifficultyPassed = true
 		engine = beaconConsensus.NewFaker()
 	}
 	genesis := &core.Genesis{

eth/ethconfig/config.go

@@ -18,7 +18,7 @@
 package ethconfig
 
 import (
-	"errors"
+	"fmt"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -162,10 +162,8 @@ type Config struct {
 // Clique is allowed for now to live standalone, but ethash is forbidden and can
 // only exist on already merged networks.
 func CreateConsensusEngine(config *params.ChainConfig, db ethdb.Database) (consensus.Engine, error) {
-	// Geth v1.14.0 dropped support for non-merged networks in any consensus
+	if config.TerminalTotalDifficulty == nil {
-	// mode. If such a network is requested, reject startup.
+		return nil, fmt.Errorf("only PoS networks are supported, please transition old ones with Geth v1.13.x")
-	if !config.TerminalTotalDifficultyPassed {
-		return nil, errors.New("only PoS networks are supported, please transition old ones with Geth v1.13.x")
 	}
 	// Wrap previously supported consensus engines into their post-merge counterpart
 	if config.Clique != nil {

eth/protocols/eth/handler_test.go

@@ -94,7 +94,6 @@ func newTestBackendWithGenerator(blocks int, shanghai bool, generator func(int,
 			MergeNetsplitBlock:      big.NewInt(0),
 			ShanghaiTime:            u64(0),
 			TerminalTotalDifficulty: big.NewInt(0),
-			TerminalTotalDifficultyPassed: true,
 			Ethash:                  new(params.EthashConfig),
 		}
 		engine = beacon.NewFaker()

eth/tracers/internal/tracetest/testdata/call_tracer/blob_tx.json

@@ -41,8 +41,7 @@
       "grayGlacierBlock": 0,
       "shanghaiTime": 0,
       "cancunTime": 0,
-      "terminalTotalDifficulty": 0,
+      "terminalTotalDifficulty": 0
-      "terminalTotalDifficultyPassed": true
     }
   },
   "context": {

eth/tracers/internal/tracetest/testdata/call_tracer_flat/nested_pointer_issue.json

@@ -61,7 +61,6 @@
       "berlinBlock": 4460644,
       "londonBlock": 5062605,
       "terminalTotalDifficulty": 10790000,
-      "terminalTotalDifficultyPassed": true,
       "clique": {
         "period": 15,
         "epoch": 30000

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/calldata.json

@@ -59,7 +59,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/delegatecall.json

@@ -116,7 +116,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/frontier_create_outofstorage.json

@@ -60,7 +60,6 @@
       "grayGlacierBlock": 15050000,
       "shanghaiTime": 1681338455,
       "terminalTotalDifficulty": 7797655526461000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/multi_contracts.json

@@ -281,7 +281,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/multilogs.json

@@ -149,7 +149,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/notopic.json

@@ -84,7 +84,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/simple.json

@@ -45,7 +45,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/tx_failed.json

@@ -119,7 +119,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/tx_partial_failed.json

@@ -57,7 +57,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/with_onlyTopCall.json

@@ -59,7 +59,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/prestate_tracer/blob_tx.json

@@ -41,8 +41,7 @@
       "grayGlacierBlock": 0,
       "shanghaiTime": 0,
       "cancunTime": 0,
-      "terminalTotalDifficulty": 0,
+      "terminalTotalDifficulty": 0
-      "terminalTotalDifficultyPassed": true
     }
   },
   "context": {

eth/tracers/internal/tracetest/testdata/prestate_tracer/create_create.json

@@ -38,7 +38,6 @@
       "grayGlacierBlock": 0,
       "shanghaiTime": 0,
       "terminalTotalDifficulty": 0,
-      "terminalTotalDifficultyPassed": true,
       "isDev": true
     }
   },

eth/tracers/internal/tracetest/testdata/prestate_tracer/create_existing_contract.json

@@ -49,7 +49,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

eth/tracers/internal/tracetest/testdata/prestate_tracer_with_diff_mode/create_failed.json

@@ -55,7 +55,6 @@
       "londonBlock": 12965000,
       "arrowGlacierBlock": 13773000,
       "grayGlacierBlock": 15050000,
-      "terminalTotalDifficultyPassed": true,
       "ethash": {}
     }
   },

graphql/graphql_test.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"math"
 	"math/big"
 	"net/http"
 	"strings"
@@ -459,13 +460,14 @@ func newGQLService(t *testing.T, stack *node.Node, shanghai bool, gspec *core.Ge
 	var engine consensus.Engine = ethash.NewFaker()
 	if shanghai {
 		engine = beacon.NewFaker()
-		chainCfg := gspec.Config
+		gspec.Config.TerminalTotalDifficulty = common.Big0
-		chainCfg.TerminalTotalDifficultyPassed = true
-		chainCfg.TerminalTotalDifficulty = common.Big0
 		// GenerateChain will increment timestamps by 10.
 		// Shanghai upgrade at block 1.
 		shanghaiTime := uint64(5)
-		chainCfg.ShanghaiTime = &shanghaiTime
+		gspec.Config.ShanghaiTime = &shanghaiTime
+	} else {
+		// set an arbitrary large ttd as chains are required to be known to be merged
+		gspec.Config.TerminalTotalDifficulty = big.NewInt(math.MaxInt64)
 	}
 	ethBackend, err := eth.New(stack, ethConf)
 	if err != nil {

params/config.go

@@ -18,6 +18,7 @@ package params
 
 import (
 	"fmt"
+	"math"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -55,7 +56,6 @@ var (
 		ArrowGlacierBlock:       big.NewInt(13_773_000),
 		GrayGlacierBlock:        big.NewInt(15_050_000),
 		TerminalTotalDifficulty: MainnetTerminalTotalDifficulty, // 58_750_000_000_000_000_000_000
-		TerminalTotalDifficultyPassed: true,
 		ShanghaiTime:            newUint64(1681338455),
 		CancunTime:              newUint64(1710338135),
 		DepositContractAddress:  common.HexToAddress("0x00000000219ab540356cbb839cbe05303d7705fa"),
@@ -80,7 +80,6 @@ var (
 		ArrowGlacierBlock:       nil,
 		GrayGlacierBlock:        nil,
 		TerminalTotalDifficulty: big.NewInt(0),
-		TerminalTotalDifficultyPassed: true,
 		MergeNetsplitBlock:      nil,
 		ShanghaiTime:            newUint64(1696000704),
 		CancunTime:              newUint64(1707305664),
@@ -105,7 +104,6 @@ var (
 		ArrowGlacierBlock:       nil,
 		GrayGlacierBlock:        nil,
 		TerminalTotalDifficulty: big.NewInt(17_000_000_000_000_000),
-		TerminalTotalDifficultyPassed: true,
 		MergeNetsplitBlock:      big.NewInt(1735371),
 		ShanghaiTime:            newUint64(1677557088),
 		CancunTime:              newUint64(1706655072),
@@ -130,13 +128,12 @@ var (
 		LondonBlock:             big.NewInt(0),
 		ArrowGlacierBlock:       big.NewInt(0),
 		GrayGlacierBlock:        big.NewInt(0),
+		TerminalTotalDifficulty: big.NewInt(math.MaxInt64),
 		MergeNetsplitBlock:      nil,
 		ShanghaiTime:            nil,
 		CancunTime:              nil,
 		PragueTime:              nil,
 		VerkleTime:              nil,
-		TerminalTotalDifficulty:       nil,
-		TerminalTotalDifficultyPassed: true,
 		Ethash:                  new(EthashConfig),
 		Clique:                  nil,
 	}
@@ -158,9 +155,8 @@ var (
 		GrayGlacierBlock:        big.NewInt(0),
 		ShanghaiTime:            newUint64(0),
 		CancunTime:              newUint64(0),
-		PragueTime:                    newUint64(0),
 		TerminalTotalDifficulty: big.NewInt(0),
-		TerminalTotalDifficultyPassed: true,
+		PragueTime:              newUint64(0),
 	}
 
 	// AllCliqueProtocolChanges contains every protocol change (EIPs) introduced
@@ -187,8 +183,7 @@ var (
 		CancunTime:              nil,
 		PragueTime:              nil,
 		VerkleTime:              nil,
-		TerminalTotalDifficulty:       nil,
+		TerminalTotalDifficulty: big.NewInt(math.MaxInt64),
-		TerminalTotalDifficultyPassed: false,
 		Ethash:                  nil,
 		Clique:                  &CliqueConfig{Period: 0, Epoch: 30000},
 	}
@@ -217,8 +212,7 @@ var (
 		CancunTime:              nil,
 		PragueTime:              nil,
 		VerkleTime:              nil,
-		TerminalTotalDifficulty:       nil,
+		TerminalTotalDifficulty: big.NewInt(math.MaxInt64),
-		TerminalTotalDifficultyPassed: false,
 		Ethash:                  new(EthashConfig),
 		Clique:                  nil,
 	}
@@ -248,7 +242,6 @@ var (
 		PragueTime:              newUint64(0),
 		VerkleTime:              nil,
 		TerminalTotalDifficulty: big.NewInt(0),
-		TerminalTotalDifficultyPassed: true,
 		Ethash:                  new(EthashConfig),
 		Clique:                  nil,
 	}
@@ -277,8 +270,7 @@ var (
 		CancunTime:              nil,
 		PragueTime:              nil,
 		VerkleTime:              nil,
-		TerminalTotalDifficulty:       nil,
+		TerminalTotalDifficulty: big.NewInt(math.MaxInt64),
-		TerminalTotalDifficultyPassed: false,
 		Ethash:                  new(EthashConfig),
 		Clique:                  nil,
 	}
@@ -332,13 +324,6 @@ type ChainConfig struct {
 	// the network that triggers the consensus upgrade.
 	TerminalTotalDifficulty *big.Int `json:"terminalTotalDifficulty,omitempty"`
 
-	// TerminalTotalDifficultyPassed is a flag specifying that the network already
-	// passed the terminal total difficulty. Its purpose is to disable legacy sync
-	// even without having seen the TTD locally (safer long term).
-	//
-	// TODO(karalabe): Drop this field eventually (always assuming PoS mode)
-	TerminalTotalDifficultyPassed bool `json:"terminalTotalDifficultyPassed,omitempty"`
-
 	DepositContractAddress common.Address `json:"depositContractAddress,omitempty"`
 
 	// Various consensus engines
@@ -377,21 +362,9 @@ func (c *ChainConfig) Description() string {
 	banner += fmt.Sprintf("Chain ID:  %v (%s)\n", c.ChainID, network)
 	switch {
 	case c.Ethash != nil:
-		if c.TerminalTotalDifficulty == nil {
-			banner += "Consensus: Ethash (proof-of-work)\n"
-		} else if !c.TerminalTotalDifficultyPassed {
-			banner += "Consensus: Beacon (proof-of-stake), merging from Ethash (proof-of-work)\n"
-		} else {
 		banner += "Consensus: Beacon (proof-of-stake), merged from Ethash (proof-of-work)\n"
-		}
 	case c.Clique != nil:
-		if c.TerminalTotalDifficulty == nil {
-			banner += "Consensus: Clique (proof-of-authority)\n"
-		} else if !c.TerminalTotalDifficultyPassed {
-			banner += "Consensus: Beacon (proof-of-stake), merging from Clique (proof-of-authority)\n"
-		} else {
 		banner += "Consensus: Beacon (proof-of-stake), merged from Clique (proof-of-authority)\n"
-		}
 	default:
 		banner += "Consensus: unknown\n"
 	}
@@ -426,18 +399,13 @@ func (c *ChainConfig) Description() string {
 	banner += "\n"
 
 	// Add a special section for the merge as it's non-obvious
-	if c.TerminalTotalDifficulty == nil {
-		banner += "The Merge is not yet available for this network!\n"
-		banner += " - Hard-fork specification: https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/paris.md\n"
-	} else {
 	banner += "Merge configured:\n"
 	banner += " - Hard-fork specification:    https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/paris.md\n"
-		banner += fmt.Sprintf(" - Network known to be merged: %v\n", c.TerminalTotalDifficultyPassed)
+	banner += " - Network known to be merged\n"
 	banner += fmt.Sprintf(" - Total terminal difficulty:  %v\n", c.TerminalTotalDifficulty)
 	if c.MergeNetsplitBlock != nil {
 		banner += fmt.Sprintf(" - Merge netsplit block:       #%-8v\n", c.MergeNetsplitBlock)
 	}
-	}
 	banner += "\n"
 
 	// Create a list of forks post-merge

tests/block_test_util.go

@@ -22,6 +22,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	stdmath "math"
 	"math/big"
 	"os"
 	"reflect"
@@ -129,6 +130,11 @@ func (t *BlockTest) Run(snapshotter bool, scheme string, witness bool, tracer *t
 	}
 	// Commit genesis state
 	gspec := t.genesis(config)
+
+	// if ttd is not specified, set an arbitrary huge value
+	if gspec.Config.TerminalTotalDifficulty == nil {
+		gspec.Config.TerminalTotalDifficulty = big.NewInt(stdmath.MaxInt64)
+	}
 	triedb := triedb.NewDatabase(db, tconf)
 	gblock, err := gspec.Commit(db, triedb)
 	if err != nil {

tests/difficulty_test.go

@@ -51,7 +51,6 @@ var (
 		BerlinBlock:             big.NewInt(9_812_189),
 		LondonBlock:             big.NewInt(10_499_401),
 		TerminalTotalDifficulty: new(big.Int).SetUint64(50_000_000_000_000_000),
-		TerminalTotalDifficultyPassed: true,
 	}
 )