// Copyright 2017 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"encoding/binary"
"errors"
"math"
"math/big"
"strings"
"github.com/dexon-foundation/dexon/common"
"github.com/dexon-foundation/dexon/common/hexutil"
math2 "github.com/dexon-foundation/dexon/common/math"
"github.com/dexon-foundation/dexon/consensus/ethash"
"github.com/dexon-foundation/dexon/core"
"github.com/dexon-foundation/dexon/params"
)
// alethGenesisSpec represents the genesis specification format used by the
// C++ Ethereum implementation.
type alethGenesisSpec struct {
SealEngine string `json:"sealEngine"`
Params struct {
AccountStartNonce math2.HexOrDecimal64 `json:"accountStartNonce"`
MaximumExtraDataSize hexutil.Uint64 `json:"maximumExtraDataSize"`
HomesteadForkBlock hexutil.Uint64 `json:"homesteadForkBlock"`
DaoHardforkBlock math2.HexOrDecimal64 `json:"daoHardforkBlock"`
EIP150ForkBlock hexutil.Uint64 `json:"EIP150ForkBlock"`
EIP158ForkBlock hexutil.Uint64 `json:"EIP158ForkBlock"`
ByzantiumForkBlock hexutil.Uint64 `json:"byzantiumForkBlock"`
ConstantinopleForkBlock hexutil.Uint64 `json:"constantinopleForkBlock"`
MinGasLimit hexutil.Uint64 `json:"minGasLimit"`
MaxGasLimit hexutil.Uint64 `json:"maxGasLimit"`
TieBreakingGas bool `json:"tieBreakingGas"`
GasLimitBoundDivisor math2.HexOrDecimal64 `json:"gasLimitBoundDivisor"`
MinimumDifficulty *hexutil.Big `json:"minimumDifficulty"`
DifficultyBoundDivisor *math2.HexOrDecimal256 `json:"difficultyBoundDivisor"`
DurationLimit *math2.HexOrDecimal256 `json:"durationLimit"`
BlockReward *hexutil.Big `json:"blockReward"`
NetworkID hexutil.Uint64 `json:"networkID"`
ChainID hexutil.Uint64 `json:"chainID"`
AllowFutureBlocks bool `json:"allowFutureBlocks"`
} `json:"params"`
Genesis struct {
Nonce hexutil.Bytes `json:"nonce"`
Difficulty *hexutil.Big `json:"difficulty"`
MixHash common.Hash `json:"mixHash"`
Author common.Address `json:"author"`
Timestamp hexutil.Uint64 `json:"timestamp"`
ParentHash common.Hash `json:"parentHash"`
ExtraData hexutil.Bytes `json:"extraData"`
GasLimit hexutil.Uint64 `json:"gasLimit"`
} `json:"genesis"`
Accounts map[common.UnprefixedAddress]*alethGenesisSpecAccount `json:"accounts"`
}
// alethGenesisSpecAccount is the prefunded genesis account and/or precompiled
// contract definition.
type alethGenesisSpecAccount struct {
Balance *math2.HexOrDecimal256 `json:"balance"`
Nonce uint64 `json:"nonce,omitempty"`
Precompiled *alethGenesisSpecBuiltin `json:"precompiled,omitempty"`
}
// alethGenesisSpecBuiltin is the precompiled contract definition.
type alethGenesisSpecBuiltin struct {
Name string `json:"name,omitempty"`
StartingBlock hexutil.Uint64 `json:"startingBlock,omitempty"`
Linear *alethGenesisSpecLinearPricing `json:"linear,omitempty"`
}
type alethGenesisSpecLinearPricing struct {
Base uint64 `json:"base"`
Word uint64 `json:"word"`
}
// newAlethGenesisSpec converts a go-ethereum genesis block into a Aleth-specific
// chain specification format.
func newAlethGenesisSpec(network string, genesis *core.Genesis) (*alethGenesisSpec, error) {
// Only ethash is currently supported between go-ethereum and aleth
if genesis.Config.Ethash == nil {
return nil, errors.New("unsupported consensus engine")
}
// Reconstruct the chain spec in Aleth format
spec := &alethGenesisSpec{
SealEngine: "Ethash",
}
// Some defaults
spec.Params.AccountStartNonce = 0
spec.Params.TieBreakingGas = false
spec.Params.AllowFutureBlocks = false
spec.Params.DaoHardforkBlock = 0
spec.Params.HomesteadForkBlock = (hexutil.Uint64)(genesis.Config.HomesteadBlock.Uint64())
spec.Params.EIP150ForkBlock = (hexutil.Uint64)(genesis.Config.EIP150Block.Uint64())
spec.Params.EIP158ForkBlock = (hexutil.Uint64)(genesis.Config.EIP158Block.Uint64())
// Byzantium
if num := genesis.Config.ByzantiumBlock; num != nil {
spec.setByzantium(num)
}
// Constantinople
if num := genesis.Config.ConstantinopleBlock; num != nil {
spec.setConstantinople(num)
}
spec.Params.NetworkID = (hexutil.Uint64)(genesis.Config.ChainID.Uint64())
spec.Params.ChainID = (hexutil.Uint64)(genesis.Config.ChainID.Uint64())
spec.Params.MaximumExtraDataSize = (hexutil.Uint64)(params.MaximumExtraDataSize)
spec.Params.MinGasLimit = (hexutil.Uint64)(params.MinGasLimit)
spec.Params.MaxGasLimit = (hexutil.Uint64)(math.MaxInt64)
spec.Params.MinimumDifficulty = (*hexutil.Big)(params.MinimumDifficulty)
spec.Params.DifficultyBoundDivisor = (*math2.HexOrDecimal256)(params.DifficultyBoundDivisor)
spec.Params.GasLimitBoundDivisor = (math2.HexOrDecimal64)(params.GasLimitBoundDivisor)
spec.Params.DurationLimit = (*math2.HexOrDecimal256)(params.DurationLimit)
spec.Params.BlockReward = (*hexutil.Big)(ethash.FrontierBlockReward)
spec.Genesis.Nonce = (hexutil.Bytes)(make([]byte, 8))
binary.LittleEndian.PutUint64(spec.Genesis.Nonce[:], genesis.Nonce)
spec.Genesis.MixHash = genesis.Mixhash
spec.Genesis.Difficulty = (*hexutil.Big)(genesis.Difficulty)
spec.Genesis.Author = genesis.Coinbase
spec.Genesis.Timestamp = (hexutil.Uint64)(genesis.Timestamp)
spec.Genesis.ParentHash = genesis.ParentHash
spec.Genesis.ExtraData = (hexutil.Bytes)(genesis.ExtraData)
spec.Genesis.GasLimit = (hexutil.Uint64)(genesis.GasLimit)
for address, account := range genesis.Alloc {
spec.setAccount(address, account)
}
spec.setPrecompile(1, &alethGenesisSpecBuiltin{Name: "ecrecover",
Linear: &alethGenesisSpecLinearPricing{Base: 3000}})
spec.setPrecompile(2, &alethGenesisSpecBuiltin{Name: "sha256",
Linear: &alethGenesisSpecLinearPricing{Base: 60, Word: 12}})
spec.setPrecompile(3, &alethGenesisSpecBuiltin{Name: "ripemd160",
Linear: &alethGenesisSpecLinearPricing{Base: 600, Word: 120}})
spec.setPrecompile(4, &alethGenesisSpecBuiltin{Name: "identity",
Linear: &alethGenesisSpecLinearPricing{Base: 15, Word: 3}})
if genesis.Config.ByzantiumBlock != nil {
spec.setPrecompile(5, &alethGenesisSpecBuiltin{Name: "modexp",
StartingBlock: (hexutil.Uint64)(genesis.Config.ByzantiumBlock.Uint64())})
spec.setPrecompile(6, &alethGenesisSpecBuiltin{Name: "alt_bn128_G1_add",
StartingBlock: (hexutil.Uint64)(genesis.Config.ByzantiumBlock.Uint64()),
Linear: &alethGenesisSpecLinearPricing{Base: 500}})
spec.setPrecompile(7, &alethGenesisSpecBuiltin{Name: "alt_bn128_G1_mul",
StartingBlock: (hexutil.Uint64)(genesis.Config.ByzantiumBlock.Uint64()),
Linear: &alethGenesisSpecLinearPricing{Base: 40000}})
spec.setPrecompile(8, &alethGenesisSpecBuiltin{Name: "alt_bn128_pairing_product",
StartingBlock: (hexutil.Uint64)(genesis.Config.ByzantiumBlock.Uint64())})
}
return spec, nil
}
func (spec *alethGenesisSpec) setPrecompile(address byte, data *alethGenesisSpecBuiltin) {
if spec.Accounts == nil {
spec.Accounts = make(map[common.UnprefixedAddress]*alethGenesisSpecAccount)
}
addr := common.UnprefixedAddress(common.BytesToAddress([]byte{address}))
if _, exist := spec.Accounts[addr]; !exist {
spec.Accounts[addr] = &alethGenesisSpecAccount{}
}
spec.Accounts[addr].Precompiled = data
}
func (spec *alethGenesisSpec) setAccount(address common.Address, account core.GenesisAccount) {
if spec.Accounts == nil {
spec.Accounts = make(map[common.UnprefixedAddress]*alethGenesisSpecAccount)
}
a, exist := spec.Accounts[common.UnprefixedAddress(address)]
if !exist {
a = &alethGenesisSpecAccount{}
spec.Accounts[common.UnprefixedAddress(address)] = a
}
a.Balance = (*math2.HexOrDecimal256)(account.Balance)
a.Nonce = account.Nonce
}
func (spec *alethGenesisSpec) setByzantium(num *big.Int) {
spec.Params.ByzantiumForkBlock = hexutil.Uint64(num.Uint64())
}
func (spec *alethGenesisSpec) setConstantinople(num *big.Int) {
spec.Params.ConstantinopleForkBlock = hexutil.Uint64(num.Uint64())
}
// parityChainSpec is the chain specification format used by Parity.
type parityChainSpec struct {
Name string `json:"name"`
Datadir string `json:"dataDir"`
Engine struct {
Ethash struct {
Params struct {
MinimumDifficulty *hexutil.Big `json:"minimumDifficulty"`
DifficultyBoundDivisor *hexutil.Big `json:"difficultyBoundDivisor"`
DurationLimit *hexutil.Big `json:"durationLimit"`
BlockReward map[string]string `json:"blockReward"`
DifficultyBombDelays map[string]string `json:"difficultyBombDelays"`
HomesteadTransition hexutil.Uint64 `json:"homesteadTransition"`
EIP100bTransition hexutil.Uint64 `json:"eip100bTransition"`
} `json:"params"`
} `json:"Ethash"`
} `json:"engine"`
Params struct {
AccountStartNonce hexutil.Uint64 `json:"accountStartNonce"`
MaximumExtraDataSize hexutil.Uint64 `json:"maximumExtraDataSize"`
MinGasLimit hexutil.Uint64 `json:"minGasLimit"`
GasLimitBoundDivisor math2.HexOrDecimal64 `json:"gasLimitBoundDivisor"`
NetworkID hexutil.Uint64 `json:"networkID"`
ChainID hexutil.Uint64 `json:"chainID"`
MaxCodeSize hexutil.Uint64 `json:"maxCodeSize"`
MaxCodeSizeTransition hexutil.Uint64 `json:"maxCodeSizeTransition"`
EIP98Transition hexutil.Uint64 `json:"eip98Transition"`
EIP150Transition hexutil.Uint64 `json:"eip150Transition"`
EIP160Transition hexutil.Uint64 `json:"eip160Transition"`
EIP161abcTransition hexutil.Uint64 `json:"eip161abcTransition"`
EIP161dTransition hexutil.Uint64 `json:"eip161dTransition"`
EIP155Transition hexutil.Uint64 `json:"eip155Transition"`
EIP140Transition hexutil.Uint64 `json:"eip140Transition"`
EIP211Transition hexutil.Uint64 `json:"eip211Transition"`
EIP214Transition hexutil.Uint64 `json:"eip214Transition"`
EIP658Transition hexutil.Uint64 `json:"eip658Transition"`
EIP145Transition hexutil.Uint64 `json:"eip145Transition"`
EIP1014Transition hexutil.Uint64 `json:"eip1014Transition"`
EIP1052Transition hexutil.Uint64 `json:"eip1052Transition"`
EIP1283Transition hexutil.Uint64 `json:"eip1283Transition"`
EIP1283DisableTransition hexutil.Uint64 `json:"eip1283DisableTransition"`
} `json:"params"`
Genesis struct {
Seal struct {
Ethereum struct {
Nonce hexutil.Bytes `json:"nonce"`
MixHash hexutil.Bytes `json:"mixHash"`
} `json:"ethereum"`
} `json:"seal"`
Difficulty *hexutil.Big `json:"difficulty"`
Author common.Address `json:"author"`
Timestamp hexutil.Uint64 `json:"timestamp"`
ParentHash common.Hash `json:"parentHash"`
ExtraData hexutil.Bytes `json:"extraData"`
GasLimit hexutil.Uint64 `json:"gasLimit"`
} `json:"genesis"`
Nodes []string `json:"nodes"`
Accounts map[common.UnprefixedAddress]*parityChainSpecAccount `json:"accounts"`
}
// parityChainSpecAccount is the prefunded genesis account and/or precompiled
// contract definition.
type parityChainSpecAccount struct {
Balance math2.HexOrDecimal256 `json:"balance"`
Nonce math2.HexOrDecimal64 `json:"nonce,omitempty"`
Builtin *parityChainSpecBuiltin `json:"builtin,omitempty"`
}
// parityChainSpecBuiltin is the precompiled contract definition.
type parityChainSpecBuiltin struct {
Name string `json:"name,omitempty"`
ActivateAt math2.HexOrDecimal64 `json:"activate_at,omitempty"`
Pricing *parityChainSpecPricing `json:"pricing,omitempty"`
}
// parityChainSpecPricing represents the different pricing models that builtin
// contracts might advertise using.
type parityChainSpecPricing struct {
Linear *parityChainSpecLinearPricing `json:"linear,omitempty"`
ModExp *parityChainSpecModExpPricing `json:"modexp,omitempty"`
AltBnPairing *parityChainSpecAltBnPairingPricing `json:"alt_bn128_pairing,omitempty"`
}
type parityChainSpecLinearPricing struct {
Base uint64 `json:"base"`
Word uint64 `json:"word"`
}
type parityChainSpecModExpPricing struct {
Divisor uint64 `json:"divisor"`
}
type parityChainSpecAltBnPairingPricing struct {
Base uint64 `json:"base"`
Pair uint64 `json:"pair"`
}
// newParityChainSpec converts a go-ethereum genesis block into a Parity specific
// chain specification format.
func newParityChainSpec(network string, genesis *core.Genesis, bootnodes []string) (*parityChainSpec, error) {
// Only ethash is currently supported between go-ethereum and Parity
if genesis.Config.Ethash == nil {
return nil, errors.New("unsupported consensus engine")
}
// Reconstruct the chain spec in Parity's format
spec := &parityChainSpec{
Name: network,
Nodes: bootnodes,
Datadir: strings.ToLower(network),
}
spec.Engine.Ethash.Params.BlockReward = make(map[string]string)
spec.Engine.Ethash.Params.DifficultyBombDelays = make(map[string]string)
// Frontier
spec.Engine.Ethash.Params.MinimumDifficulty = (*hexutil.Big)(params.MinimumDifficulty)
spec.Engine.Ethash.Params.DifficultyBoundDivisor = (*hexutil.Big)(params.DifficultyBoundDivisor)
spec.Engine.Ethash.Params.DurationLimit = (*hexutil.Big)(params.DurationLimit)
spec.Engine.Ethash.Params.BlockReward["0x0"] = hexutil.EncodeBig(ethash.FrontierBlockReward)
// Homestead
spec.Engine.Ethash.Params.HomesteadTransition = hexutil.Uint64(genesis.Config.HomesteadBlock.Uint64())
// Tangerine Whistle : 150
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-608.md
spec.Params.EIP150Transition = hexutil.Uint64(genesis.Config.EIP150Block.Uint64())
// Spurious Dragon: 155, 160, 161, 170
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-607.md
spec.Params.EIP155Transition = hexutil.Uint64(genesis.Config.EIP155Block.Uint64())
spec.Params.EIP160Transition = hexutil.Uint64(genesis.Config.EIP155Block.Uint64())
spec.Params.EIP161abcTransition = hexutil.Uint64(genesis.Config.EIP158Block.Uint64())
spec.Params.EIP161dTransition = hexutil.Uint64(genesis.Config.EIP158Block.Uint64())
// Byzantium
if num := genesis.Config.ByzantiumBlock; num != nil {
spec.setByzantium(num)
}
// Constantinople
if num := genesis.Config.ConstantinopleBlock; num != nil {
spec.setConstantinople(num)
}
// ConstantinopleFix (remove eip-1283)
if num := genesis.Config.PetersburgBlock; num != nil {
spec.setConstantinopleFix(num)
}
spec.Params.MaximumExtraDataSize = (hexutil.Uint64)(params.MaximumExtraDataSize)
spec.Params.MinGasLimit = (hexutil.Uint64)(params.MinGasLimit)
spec.Params.GasLimitBoundDivisor = (math2.HexOrDecimal64)(params.GasLimitBoundDivisor)
spec.Params.NetworkID = (hexutil.Uint64)(genesis.Config.ChainID.Uint64())
spec.Params.ChainID = (hexutil.Uint64)(genesis.Config.ChainID.Uint64())
spec.Params.MaxCodeSize = params.MaxCodeSize
// geth has it set from zero
spec.Params.MaxCodeSizeTransition = 0
// Disable this one
spec.Params.EIP98Transition = math.MaxInt64
spec.Genesis.Seal.Ethereum.Nonce = (hexutil.Bytes)(make([]byte, 8))
binary.LittleEndian.PutUint64(spec.Genesis.Seal.Ethereum.Nonce[:], genesis.Nonce)
spec.Genesis.Seal.Ethereum.MixHash = (hexutil.Bytes)(genesis.Mixhash[:])
spec.Genesis.Difficulty = (*hexutil.Big)(genesis.Difficulty)
spec.Genesis.Author = genesis.Coinbase
spec.Genesis.Timestamp = (hexutil.Uint64)(genesis.Timestamp)
spec.Genesis.ParentHash = genesis.ParentHash
spec.Genesis.ExtraData = (hexutil.Bytes)(genesis.ExtraData)
spec.Genesis.GasLimit = (hexutil.Uint64)(genesis.GasLimit)
spec.Accounts = make(map[common.UnprefixedAddress]*parityChainSpecAccount)
for address, account := range genesis.Alloc {
bal := math2.HexOrDecimal256(*account.Balance)
spec.Accounts[common.UnprefixedAddress(address)] = &parityChainSpecAccount{
Balance: bal,
Nonce: math2.HexOrDecimal64(account.Nonce),
}
}
spec.setPrecompile(1, &parityChainSpecBuiltin{Name: "ecrecover",
Pricing: &parityChainSpecPricing{Linear: &parityChainSpecLinearPricing{Base: 3000}}})
spec.setPrecompile(2, &parityChainSpecBuiltin{
Name: "sha256", Pricing: &parityChainSpecPricing{Linear: &parityChainSpecLinearPricing{Base: 60, Word: 12}},
})
spec.setPrecompile(3, &parityChainSpecBuiltin{
Name: "ripemd160", Pricing: &parityChainSpecPricing{Linear: &parityChainSpecLinearPricing{Base: 600, Word: 120}},
})
spec.setPrecompile(4, &parityChainSpecBuiltin{
Name: "identity", Pricing: &parityChainSpecPricing{Linear: &parityChainSpecLinearPricing{Base: 15, Word: 3}},
})
if genesis.Config.ByzantiumBlock != nil {
blnum := math2.HexOrDecimal64(genesis.Config.ByzantiumBlock.Uint64())
spec.setPrecompile(5, &parityChainSpecBuiltin{
Name: "modexp", ActivateAt: blnum, Pricing: &parityChainSpecPricing{ModExp: &parityChainSpecModExpPricing{Divisor: 20}},
})
spec.setPrecompile(6, &parityChainSpecBuiltin{
Name: "alt_bn128_add", ActivateAt: blnum, Pricing: &parityChainSpecPricing{Linear: &parityChainSpecLinearPricing{Base: 500}},
})
spec.setPrecompile(7, &parityChainSpecBuiltin{
Name: "alt_bn128_mul", ActivateAt: blnum, Pricing: &parityChainSpecPricing{Linear: &parityChainSpecLinearPricing{Base: 40000}},
})
spec.setPrecompile(8, &parityChainSpecBuiltin{
Name: "alt_bn128_pairing", ActivateAt: blnum, Pricing: &parityChainSpecPricing{AltBnPairing: &parityChainSpecAltBnPairingPricing{Base: 100000, Pair: 80000}},
})
}
return spec, nil
}
func (spec *parityChainSpec) setPrecompile(address byte, data *parityChainSpecBuiltin) {
if spec.Accounts == nil {
spec.Accounts = make(map[common.UnprefixedAddress]*parityChainSpecAccount)
}
a := common.UnprefixedAddress(common.BytesToAddress([]byte{address}))
if _, exist := spec.Accounts[a]; !exist {
spec.Accounts[a] = &parityChainSpecAccount{}
}
spec.Accounts[a].Builtin = data
}
func (spec *parityChainSpec) setByzantium(num *big.Int) {
spec.Engine.Ethash.Params.BlockReward[hexutil.EncodeBig(num)] = hexutil.EncodeBig(ethash.ByzantiumBlockReward)
spec.Engine.Ethash.Params.DifficultyBombDelays[hexutil.EncodeBig(num)] = hexutil.EncodeUint64(3000000)
n := hexutil.Uint64(num.Uint64())
spec.Engine.Ethash.Params.EIP100bTransition = n
spec.Params.EIP140Transition = n
spec.Params.EIP211Transition = n
spec.Params.EIP214Transition = n
spec.Params.EIP658Transition = n
}
func (spec *parityChainSpec) setConstantinople(num *big.Int) {
spec.Engine.Ethash.Params.BlockReward[hexutil.EncodeBig(num)] = hexutil.EncodeBig(ethash.ConstantinopleBlockReward)
spec.Engine.Ethash.Params.DifficultyBombDelays[hexutil.EncodeBig(num)] = hexutil.EncodeUint64(2000000)
n := hexutil.Uint64(num.Uint64())
spec.Params.EIP145Transition = n
spec.Params.EIP1014Transition = n
spec.Params.EIP1052Transition = n
spec.Params.EIP1283Transition = n
}
func (spec *parityChainSpec) setConstantinopleFix(num *big.Int) {
spec.Params.EIP1283DisableTransition = hexutil.Uint64(num.Uint64())
}
// pyEthereumGenesisSpec represents the genesis specification format used by the
// Python Ethereum implementation.
type pyEthereumGenesisSpec struct {
Nonce hexutil.Bytes `json:"nonce"`
Timestamp hexutil.Uint64 `json:"timestamp"`
ExtraData hexutil.Bytes `json:"extraData"`
GasLimit hexutil.Uint64 `json:"gasLimit"`
Difficulty *hexutil.Big `json:"difficulty"`
Mixhash common.Hash `json:"mixhash"`
Coinbase common.Address `json:"coinbase"`
Alloc core.GenesisAlloc `json:"alloc"`
ParentHash common.Hash `json:"parentHash"`
}
// newPyEthereumGenesisSpec converts a go-ethereum genesis block into a Parity specific
// chain specification format.
func newPyEthereumGenesisSpec(network string, genesis *core.Genesis) (*pyEthereumGenesisSpec, error) {
// Only ethash is currently supported between go-ethereum and pyethereum
if genesis.Config.Ethash == nil {
return nil, errors.New("unsupported consensus engine")
}
spec := &pyEthereumGenesisSpec{
Timestamp: (hexutil.Uint64)(genesis.Timestamp),
ExtraData: genesis.ExtraData,
GasLimit: (hexutil.Uint64)(genesis.GasLimit),
Difficulty: (*hexutil.Big)(genesis.Difficulty),
Mixhash: genesis.Mixhash,
Coinbase: genesis.Coinbase,
Alloc: genesis.Alloc,
ParentHash: genesis.ParentHash,
}
spec.Nonce = (hexutil.Bytes)(make([]byte, 8))
binary.LittleEndian.PutUint64(spec.Nonce[:], genesis.Nonce)
return spec, nil
}