From e6ff50dbfb178949d4387dba10f83e869a154eb2 Mon Sep 17 00:00:00 2001
From: Arya Nair <aryaajitnair@gmail.com>
Date: Mon, 26 May 2025 16:39:29 +0530
Subject: [PATCH] cmd/geth: update DeveloperGenesisBlock usage to return faucet
 address and key, enhance dev account display

---
 cmd/geth/chaincmd.go |  2 +-
 cmd/geth/main.go     | 16 ++++++++++++++++
 cmd/utils/flags.go   |  2 +-
 core/genesis.go      | 28 +++++++++++++++++++++-------
 4 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/cmd/geth/chaincmd.go b/cmd/geth/chaincmd.go
index dc071725c1..0d8154cdfd 100644
--- a/cmd/geth/chaincmd.go
+++ b/cmd/geth/chaincmd.go
@@ -304,7 +304,7 @@ func dumpGenesis(ctx *cli.Context) error {
 	if utils.IsNetworkPreset(ctx) {
 		genesis = utils.MakeGenesis(ctx)
 	} else if ctx.IsSet(utils.DeveloperFlag.Name) && !ctx.IsSet(utils.DataDirFlag.Name) {
-		genesis = core.DeveloperGenesisBlock(11_500_000, nil)
+		genesis, _, _ = core.DeveloperGenesisBlock(11_500_000, nil)
 	}
 
 	if genesis != nil {
diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index 82991e3aee..624d6bf5a4 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -18,6 +18,7 @@
 package main
 
 import (
+	"encoding/hex"
 	"fmt"
 	"os"
 	"slices"
@@ -29,6 +30,8 @@ import (
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/console/prompt"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/internal/debug"
@@ -342,7 +345,20 @@ func geth(ctx *cli.Context) error {
 	defer stack.Close()
 
 	startNode(ctx, stack, false)
+
+	if ctx.IsSet(utils.DeveloperFlag.Name) && !ctx.IsSet(utils.DataDirFlag.Name) {
+		_, faucetAddr, faucetKey := core.DeveloperGenesisBlock(0, nil)
+		fmt.Println("Developer Faucet Account")
+		fmt.Println("========================")
+		fmt.Printf("Address: %s\n", faucetAddr.Hex())
+		if faucetKey != nil {
+			fmt.Printf("Private Key: 0x%s\n", hex.EncodeToString(crypto.FromECDSA(faucetKey)))
+		}
+		fmt.Println()
+	}
+
 	stack.Wait()
+
 	return nil
 }
 
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 81c4172a53..3d550dfdec 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -1787,7 +1787,7 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 		log.Info("Using developer account", "address", developer.Address)
 
 		// Create a new developer genesis block or reuse existing one
-		cfg.Genesis = core.DeveloperGenesisBlock(ctx.Uint64(DeveloperGasLimitFlag.Name), &developer.Address)
+		cfg.Genesis, _, _ = core.DeveloperGenesisBlock(ctx.Uint64(DeveloperGasLimitFlag.Name), &developer.Address)
 		if ctx.IsSet(DataDirFlag.Name) {
 			chaindb := tryMakeReadOnlyDatabase(ctx, stack)
 			if rawdb.ReadCanonicalHash(chaindb, 0) != (common.Hash{}) {
diff --git a/core/genesis.go b/core/genesis.go
index 620886bfaf..a3e67f53e1 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -24,6 +24,8 @@ import (
 	"math/big"
 	"strings"
 
+	"crypto/ecdsa"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/math"
@@ -644,12 +646,27 @@ func DefaultHoodiGenesisBlock() *Genesis {
 	}
 }
 
-// DeveloperGenesisBlock returns the 'geth --dev' genesis block.
-func DeveloperGenesisBlock(gasLimit uint64, faucet *common.Address) *Genesis {
+// DeveloperGenesisBlock returns the 'geth --dev' genesis block, faucet address, and key.
+func DeveloperGenesisBlock(gasLimit uint64, faucet *common.Address) (*Genesis, common.Address, *ecdsa.PrivateKey) {
 	config := *params.AllDevChainProtocolChanges
 
 	alloc := make(map[common.Address]types.Account)
 
+	var faucetAddr common.Address
+	var faucetKey *ecdsa.PrivateKey
+	if faucet == nil {
+		// Generate a new dev account for the faucet
+		key, err := crypto.GenerateKey()
+		if err != nil {
+			panic(fmt.Errorf("failed to generate dev faucet key: %w", err))
+		}
+		faucetAddr = crypto.PubkeyToAddress(key.PublicKey)
+		faucetKey = key
+	} else {
+		faucetAddr = *faucet
+	}
+	alloc[faucetAddr] = types.Account{Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))}
+
 	// Add precompiles and system contracts
 	precompileAddrs := [][]byte{
 		{0x01}, {0x02}, {0x03}, {0x04}, {0x05}, {0x06}, {0x07}, {0x08}, {0x09}, {0x0a}, {0x0b}, {0x0c}, {0x0d}, {0x0e}, {0x0f}, {0x10}, {0x11},
@@ -662,18 +679,15 @@ func DeveloperGenesisBlock(gasLimit uint64, faucet *common.Address) *Genesis {
 	alloc[params.WithdrawalQueueAddress] = types.Account{Nonce: 1, Code: params.WithdrawalQueueCode, Balance: common.Big0}
 	alloc[params.ConsolidationQueueAddress] = types.Account{Nonce: 1, Code: params.ConsolidationQueueCode, Balance: common.Big0}
 
-	if faucet != nil {
-		alloc[*faucet] = types.Account{Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))}
-	}
-
 	genesis := &Genesis{
 		Config:     &config,
 		GasLimit:   gasLimit,
 		BaseFee:    big.NewInt(params.InitialBaseFee),
 		Difficulty: big.NewInt(0),
 		Alloc:      alloc,
+		Coinbase:   faucetAddr,
 	}
-	return genesis
+	return genesis, faucetAddr, faucetKey
 }
 
 func decodePrealloc(data string) types.GenesisAlloc {