core/genesis: support chapel to run without geth init

README.md

@@ -149,15 +149,8 @@ unzip testnet.zip
 #### 3. Download snapshot
 Download latest chaindata snapshot from [here](https://github.com/bnb-chain/bsc-snapshots). Follow the guide to structure your files.
 
-Note: if you can not download the chaindata snapshot and want to sync from genesis, you have to generate the genesis block first, you have already get the genesis.json in Step 2.
-So just run: 
-``` shell
-## It will init genesis with Hash-Base Storage Scheme by default.
-geth --datadir <datadir> init ./genesis.json
-
-## It will init genesis with Path-Base Storage Scheme.
-geth --datadir <datadir> --state.scheme path init ./genesis.json
-```
+Note: If you encounter difficulties downloading the chaindata snapshot and prefer to synchronize from the genesis block on the Chapel testnet, remember to include the additional flag `--chapel` when initially launching Geth.
+
 #### 4. Start a full node
 ```shell
 ./geth --config ./config.toml --datadir ./node  --cache 8000 --rpc.allow-unprotected-txs --history.transactions 0

cmd/geth/dbcmd.go

@@ -120,6 +120,7 @@ a data corruption.`,
 			utils.DataDirFlag,
 			utils.SyncModeFlag,
 			utils.BSCMainnetFlag,
+			utils.ChapelFlag,
 			utils.StateSchemeFlag,
 		},
 		Description: "This command looks up the specified trie node key from the database.",
@@ -133,6 +134,7 @@ a data corruption.`,
 			utils.DataDirFlag,
 			utils.SyncModeFlag,
 			utils.BSCMainnetFlag,
+			utils.ChapelFlag,
 			utils.StateSchemeFlag,
 		},
 		Description: "This command delete the specify trie node from the database.",

cmd/geth/main.go

@@ -292,6 +292,9 @@ func main() {
 func prepare(ctx *cli.Context) {
 	// If we're running a known preset, log it for convenience.
 	switch {
+	case ctx.IsSet(utils.ChapelFlag.Name):
+		log.Info("Starting BSC on Chapel testnet...")
+
 	case ctx.IsSet(utils.DeveloperFlag.Name):
 		log.Info("Starting Geth in ephemeral dev mode...")
 		log.Warn(`You are running Geth in --dev mode. Please note the following:
@@ -316,7 +319,8 @@ func prepare(ctx *cli.Context) {
 	// If we're a full node on mainnet without --cache specified, bump default cache allowance
 	if ctx.String(utils.SyncModeFlag.Name) != "light" && !ctx.IsSet(utils.CacheFlag.Name) && !ctx.IsSet(utils.NetworkIdFlag.Name) {
 		// Make sure we're not on any supported preconfigured testnet either
-		if !ctx.IsSet(utils.DeveloperFlag.Name) {
+		if !ctx.IsSet(utils.DeveloperFlag.Name) &&
+			!ctx.IsSet(utils.ChapelFlag.Name) {
 			// Nope, we're really on mainnet. Bump that cache up!
 			log.Info("Bumping default cache on mainnet", "provided", ctx.Int(utils.CacheFlag.Name), "updated", 4096)
 			ctx.Set(utils.CacheFlag.Name, strconv.Itoa(4096))

cmd/utils/flags.go

@@ -164,15 +164,20 @@ var (
 	}
 	NetworkIdFlag = &cli.Uint64Flag{
 		Name:     "networkid",
-		Usage:    "Explicitly set network id (integer)(For testnets: use --goerli, --sepolia, --holesky instead)",
+		Usage:    "Explicitly set network id (integer)(For testnets: use --chapel instead)",
 		Value:    ethconfig.Defaults.NetworkId,
 		Category: flags.EthCategory,
 	}
 	BSCMainnetFlag = &cli.BoolFlag{
-		Name:     "bsc",
+		Name:     "mainnet",
 		Usage:    "BSC mainnet",
 		Category: flags.EthCategory,
 	}
+	ChapelFlag = &cli.BoolFlag{
+		Name:     "chapel",
+		Usage:    "Chapel network: pre-configured Proof-of-Stake-Authority BSC test network",
+		Category: flags.EthCategory,
+	}
 	DeveloperFlag = &cli.BoolFlag{
 		Name:     "dev",
 		Usage:    "Ephemeral proof-of-authority network with a pre-funded developer account, mining enabled",
@@ -1110,7 +1115,9 @@ Please note that --` + MetricsHTTPFlag.Name + ` must be set to start the server.
 
 var (
 	// TestnetFlags is the flag group of all built-in supported testnets.
-	TestnetFlags = []cli.Flag{}
+	TestnetFlags = []cli.Flag{
+		ChapelFlag,
+	}
 	// NetworkFlags is the flag group of all built-in supported networks.
 	NetworkFlags = append([]cli.Flag{BSCMainnetFlag}, TestnetFlags...)
 
@@ -1843,7 +1850,7 @@ func CheckExclusive(ctx *cli.Context, args ...interface{}) {
 // SetEthConfig applies eth-related command line flags to the config.
 func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 	// Avoid conflicting network flags
-	CheckExclusive(ctx, BSCMainnetFlag, DeveloperFlag)
+	CheckExclusive(ctx, BSCMainnetFlag, DeveloperFlag, ChapelFlag)
 	CheckExclusive(ctx, LightServeFlag, SyncModeFlag, "light")
 	CheckExclusive(ctx, DeveloperFlag, ExternalSignerFlag) // Can't use both ephemeral unlocked and external signer
 
@@ -2038,6 +2045,12 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 		}
 		cfg.Genesis = core.DefaultBSCGenesisBlock()
 		SetDNSDiscoveryDefaults(cfg, params.BSCGenesisHash)
+	case ctx.Bool(ChapelFlag.Name):
+		if !ctx.IsSet(NetworkIdFlag.Name) {
+			cfg.NetworkId = 97
+		}
+		cfg.Genesis = core.DefaultChapelGenesisBlock()
+		SetDNSDiscoveryDefaults(cfg, params.ChapelGenesisHash)
 	case ctx.Bool(DeveloperFlag.Name):
 		if !ctx.IsSet(NetworkIdFlag.Name) {
 			cfg.NetworkId = 1337
@@ -2399,6 +2412,8 @@ func MakeGenesis(ctx *cli.Context) *core.Genesis {
 	switch {
 	case ctx.Bool(BSCMainnetFlag.Name):
 		genesis = core.DefaultBSCGenesisBlock()
+	case ctx.Bool(ChapelFlag.Name):
+		genesis = core.DefaultChapelGenesisBlock()
 	case ctx.Bool(DeveloperFlag.Name):
 		Fatalf("Developer chains are ephemeral")
 	}

core/genesis.go

@@ -572,6 +572,22 @@ func DefaultBSCGenesisBlock() *Genesis {
 	}
 }
 
+// DefaultChapelGenesisBlock returns the BSC mainnet genesis block.
+func DefaultChapelGenesisBlock() *Genesis {
+	alloc := decodePrealloc(bscChapelAllocData)
+	return &Genesis{
+		Config:     params.ChapelChainConfig,
+		Nonce:      0,
+		ExtraData:  hexutil.MustDecode("0x00000000000000000000000000000000000000000000000000000000000000001284214b9b9c85549ab3d2b972df0deef66ac2c9b71b214cb885500844365e95cd9942c7276e7fd8a2959d3f95eae5dc7d70144ce1b73b403b7eb6e0980a75ecd1309ea12fa2ed87a8744fbfc9b863d535552c16704d214347f29fa77f77da6d75d7c752f474cf03cceff28abc65c9cbae594f725c80e12d0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+		GasLimit:   40000000,
+		Difficulty: big.NewInt(1),
+		Mixhash:    common.Hash(hexutil.MustDecode("0x0000000000000000000000000000000000000000000000000000000000000000")),
+		Coinbase:   common.HexToAddress("0xffffFFFfFFffffffffffffffFfFFFfffFFFfFFfE"),
+		Timestamp:  0x5e9da7ce,
+		Alloc:      alloc,
+	}
+}
+
 // DeveloperGenesisBlock returns the 'geth --dev' genesis block.
 func DeveloperGenesisBlock(gasLimit uint64, faucet common.Address) *Genesis {
 	// Override the default period to the user requested one