core, params, beacon/engine: implement EIP 4788 BeaconRoot (#27849)

This change implements "EIP 4788 : Beacon block root in the EVM". It implements version-2 of EPI-4788, main difference being that the contract is an actual contract rather than a precompile, as in #27289.

core/genesis.go

@@ -487,6 +487,9 @@ func (g *Genesis) ToBlock() *types.Block {
 			if head.BlobGasUsed == nil {
 				head.BlobGasUsed = new(uint64)
 			}
+			if head.BeaconRoot == nil {
+				head.BeaconRoot = new(common.Hash)
+			}
 		}
 	}
 	return types.NewBlock(head, nil, nil, nil, trie.NewStackTrie(nil)).WithWithdrawals(withdrawals)

core/state_processor.go

@@ -76,6 +76,9 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 		vmenv   = vm.NewEVM(context, vm.TxContext{}, statedb, p.config, cfg)
 		signer  = types.MakeSigner(p.config, header.Number, header.Time)
 	)
+	if beaconRoot := block.BeaconRoot(); beaconRoot != nil {
+		ProcessBeaconBlockRoot(*beaconRoot, vmenv, statedb)
+	}
 	// Iterate over and process the individual transactions
 	for i, tx := range block.Transactions() {
 		msg, err := TransactionToMessage(tx, signer, header.BaseFee)
@@ -160,3 +163,23 @@ func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *commo
 	vmenv := vm.NewEVM(blockContext, vm.TxContext{BlobHashes: tx.BlobHashes()}, statedb, config, cfg)
 	return applyTransaction(msg, config, gp, statedb, header.Number, header.Hash(), tx, usedGas, vmenv)
 }
+
+// ProcessBeaconBlockRoot applies the EIP-4788 system call to the beacon block root
+// contract. This method is exported to be used in tests.
+func ProcessBeaconBlockRoot(beaconRoot common.Hash, vmenv *vm.EVM, statedb *state.StateDB) {
+	// If EIP-4788 is enabled, we need to invoke the beaconroot storage contract with
+	// the new root
+	msg := &Message{
+		From:      params.SystemAddress,
+		GasLimit:  30_000_000,
+		GasPrice:  common.Big0,
+		GasFeeCap: common.Big0,
+		GasTipCap: common.Big0,
+		To:        &params.BeaconRootsStorageAddress,
+		Data:      beaconRoot[:],
+	}
+	vmenv.Reset(NewEVMTxContext(msg), statedb)
+	statedb.AddAddressToAccessList(params.BeaconRootsStorageAddress)
+	_, _, _ = vmenv.Call(vm.AccountRef(msg.From), *msg.To, msg.Data, 30_000_000, common.Big0)
+	statedb.Finalise(true)
+}

core/state_processor_test.go

@@ -410,6 +410,9 @@ func GenerateBadBlock(parent *types.Block, engine consensus.Engine, txs types.Tr
 		used := uint64(nBlobs * params.BlobTxBlobGasPerBlob)
 		header.ExcessBlobGas = &excess
 		header.BlobGasUsed = &used
+
+		beaconRoot := common.HexToHash("0xbeac00")
+		header.BeaconRoot = &beaconRoot
 	}
 	// Assemble and return the final block for sealing
 	if config.IsShanghai(header.Number, header.Time) {

core/types/block.go

@@ -90,6 +90,9 @@ type Header struct {
 
 	// ExcessBlobGas was added by EIP-4844 and is ignored in legacy headers.
 	ExcessBlobGas *uint64 `json:"excessBlobGas" rlp:"optional"`
+
+	// BeaconRoot was added by EIP-4788 and is ignored in legacy headers.
+	BeaconRoot *common.Hash `json:"parentBeaconBlockRoot" rlp:"optional"`
 }
 
 // field type overrides for gencodec
@@ -297,6 +300,10 @@ func CopyHeader(h *Header) *Header {
 		cpy.BlobGasUsed = new(uint64)
 		*cpy.BlobGasUsed = *h.BlobGasUsed
 	}
+	if h.BeaconRoot != nil {
+		cpy.BeaconRoot = new(common.Hash)
+		*cpy.BeaconRoot = *h.BeaconRoot
+	}
 	return &cpy
 }
 
@@ -376,6 +383,8 @@ func (b *Block) BaseFee() *big.Int {
 	return new(big.Int).Set(b.header.BaseFee)
 }
 
+func (b *Block) BeaconRoot() *common.Hash { return b.header.BeaconRoot }
+
 func (b *Block) ExcessBlobGas() *uint64 {
 	var excessBlobGas *uint64
 	if b.header.ExcessBlobGas != nil {

core/types/gen_header_json.go

@@ -35,6 +35,7 @@ func (h Header) MarshalJSON() ([]byte, error) {
 		WithdrawalsHash *common.Hash    `json:"withdrawalsRoot" rlp:"optional"`
 		BlobGasUsed     *hexutil.Uint64 `json:"blobGasUsed" rlp:"optional"`
 		ExcessBlobGas   *hexutil.Uint64 `json:"excessBlobGas" rlp:"optional"`
+		BeaconRoot      *common.Hash    `json:"parentBeaconBlockRoot" rlp:"optional"`
 		Hash            common.Hash     `json:"hash"`
 	}
 	var enc Header
@@ -57,6 +58,7 @@ func (h Header) MarshalJSON() ([]byte, error) {
 	enc.WithdrawalsHash = h.WithdrawalsHash
 	enc.BlobGasUsed = (*hexutil.Uint64)(h.BlobGasUsed)
 	enc.ExcessBlobGas = (*hexutil.Uint64)(h.ExcessBlobGas)
+	enc.BeaconRoot = h.BeaconRoot
 	enc.Hash = h.Hash()
 	return json.Marshal(&enc)
 }
@@ -83,6 +85,7 @@ func (h *Header) UnmarshalJSON(input []byte) error {
 		WithdrawalsHash *common.Hash    `json:"withdrawalsRoot" rlp:"optional"`
 		BlobGasUsed     *hexutil.Uint64 `json:"blobGasUsed" rlp:"optional"`
 		ExcessBlobGas   *hexutil.Uint64 `json:"excessBlobGas" rlp:"optional"`
+		BeaconRoot      *common.Hash    `json:"parentBeaconBlockRoot" rlp:"optional"`
 	}
 	var dec Header
 	if err := json.Unmarshal(input, &dec); err != nil {
@@ -157,5 +160,8 @@ func (h *Header) UnmarshalJSON(input []byte) error {
 	if dec.ExcessBlobGas != nil {
 		h.ExcessBlobGas = (*uint64)(dec.ExcessBlobGas)
 	}
+	if dec.BeaconRoot != nil {
+		h.BeaconRoot = dec.BeaconRoot
+	}
 	return nil
 }

core/types/gen_header_rlp.go

@@ -44,7 +44,8 @@ func (obj *Header) EncodeRLP(_w io.Writer) error {
 	_tmp2 := obj.WithdrawalsHash != nil
 	_tmp3 := obj.BlobGasUsed != nil
 	_tmp4 := obj.ExcessBlobGas != nil
-	if _tmp1 || _tmp2 || _tmp3 || _tmp4 {
+	_tmp5 := obj.BeaconRoot != nil
+	if _tmp1 || _tmp2 || _tmp3 || _tmp4 || _tmp5 {
 		if obj.BaseFee == nil {
 			w.Write(rlp.EmptyString)
 		} else {
@@ -54,27 +55,34 @@ func (obj *Header) EncodeRLP(_w io.Writer) error {
 			w.WriteBigInt(obj.BaseFee)
 		}
 	}
-	if _tmp2 || _tmp3 || _tmp4 {
+	if _tmp2 || _tmp3 || _tmp4 || _tmp5 {
 		if obj.WithdrawalsHash == nil {
 			w.Write([]byte{0x80})
 		} else {
 			w.WriteBytes(obj.WithdrawalsHash[:])
 		}
 	}
-	if _tmp3 || _tmp4 {
+	if _tmp3 || _tmp4 || _tmp5 {
 		if obj.BlobGasUsed == nil {
 			w.Write([]byte{0x80})
 		} else {
 			w.WriteUint64((*obj.BlobGasUsed))
 		}
 	}
-	if _tmp4 {
+	if _tmp4 || _tmp5 {
 		if obj.ExcessBlobGas == nil {
 			w.Write([]byte{0x80})
 		} else {
 			w.WriteUint64((*obj.ExcessBlobGas))
 		}
 	}
+	if _tmp5 {
+		if obj.BeaconRoot == nil {
+			w.Write([]byte{0x80})
+		} else {
+			w.WriteBytes(obj.BeaconRoot[:])
+		}
+	}
 	w.ListEnd(_tmp0)
 	return w.Flush()
 }