diff --git a/core/bintrie_transition_test.go b/core/bintrie_transition_test.go
new file mode 100644
index 0000000000..4c3aff90f8
--- /dev/null
+++ b/core/bintrie_transition_test.go
@@ -0,0 +1,107 @@
+// Copyright 2026 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package core
+
+import (
+ "math/big"
+ "testing"
+
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/consensus/beacon"
+ "github.com/ethereum/go-ethereum/consensus/ethash"
+ "github.com/ethereum/go-ethereum/params"
+)
+
+// TestBinaryTransitionRegistryBootstrap exercises the registry deployment on
+// the first UBT block: pre-fork blocks must leave the registry uninitialised,
+// the first UBT block must mark started=true and the base root must be
+// captured for every subsequent UBT block.
+func TestBinaryTransitionRegistryBootstrap(t *testing.T) {
+ var (
+ ubtTime uint64 = 30
+ coinbase = common.HexToAddress("0x71562b71999873DB5b286dF957af199Ec94617F7")
+ gspec = &Genesis{
+ Config: ¶ms.ChainConfig{
+ ChainID: big.NewInt(1),
+ HomesteadBlock: big.NewInt(0),
+ EIP150Block: big.NewInt(0),
+ EIP155Block: big.NewInt(0),
+ EIP158Block: big.NewInt(0),
+ ByzantiumBlock: big.NewInt(0),
+ ConstantinopleBlock: big.NewInt(0),
+ PetersburgBlock: big.NewInt(0),
+ IstanbulBlock: big.NewInt(0),
+ MuirGlacierBlock: big.NewInt(0),
+ BerlinBlock: big.NewInt(0),
+ LondonBlock: big.NewInt(0),
+ Ethash: new(params.EthashConfig),
+ ShanghaiTime: u64(0),
+ CancunTime: u64(0),
+ PragueTime: u64(0),
+ UBTTime: &ubtTime,
+ TerminalTotalDifficulty: common.Big0,
+ EnableUBTAtGenesis: false,
+ BlobScheduleConfig: ¶ms.BlobScheduleConfig{
+ Cancun: params.DefaultCancunBlobConfig,
+ Prague: params.DefaultPragueBlobConfig,
+ UBT: params.DefaultPragueBlobConfig,
+ },
+ },
+ Alloc: GenesisAlloc{
+ coinbase: {
+ Balance: big.NewInt(1000000000000000000),
+ },
+ params.BeaconRootsAddress: {Nonce: 1, Code: params.BeaconRootsCode, Balance: common.Big0},
+ params.HistoryStorageAddress: {Nonce: 1, Code: params.HistoryStorageCode, Balance: common.Big0},
+ params.WithdrawalQueueAddress: {Nonce: 1, Code: params.WithdrawalQueueCode, Balance: common.Big0},
+ params.ConsolidationQueueAddress: {Nonce: 1, Code: params.ConsolidationQueueCode, Balance: common.Big0},
+ },
+ }
+ )
+ config := gspec.Config
+ engine := beacon.New(ethash.NewFaker())
+
+ registryAddr := params.BinaryTransitionRegistryAddress
+ slotStarted := common.Hash{}
+ slotBaseRoot := common.BytesToHash([]byte{5})
+
+ GenerateChainWithGenesis(gspec, engine, 6, func(i int, gen *BlockGen) {
+ gen.SetPoS()
+
+ blockNum := gen.Number()
+ blockTime := gen.Timestamp()
+ isUBT := config.IsUBT(blockNum, blockTime)
+
+ started := gen.GetState(registryAddr, slotStarted)
+ baseRoot := gen.GetState(registryAddr, slotBaseRoot)
+ t.Logf("block %d: num=%d time=%d isUBT=%v started=%x baseRoot=%x",
+ i, blockNum.Uint64(), blockTime, isUBT, started, baseRoot)
+
+ if !isUBT {
+ if started != (common.Hash{}) {
+ t.Errorf("block %d: pre-transition block should not have registry initialized", i)
+ }
+ return
+ }
+ if started == (common.Hash{}) {
+ t.Errorf("block %d: UBT block should have registry slot 0 (started) set", i)
+ }
+ if baseRoot == (common.Hash{}) {
+ t.Errorf("block %d: UBT block should have registry slot 5 (base root) set", i)
+ }
+ })
+}
diff --git a/core/blockchain.go b/core/blockchain.go
index 296ef6bc16..882fb86927 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -38,6 +38,7 @@ import (
"github.com/ethereum/go-ethereum/consensus"
"github.com/ethereum/go-ethereum/consensus/misc/eip4844"
"github.com/ethereum/go-ethereum/core/history"
+ "github.com/ethereum/go-ethereum/core/overlay"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/state/snapshot"
@@ -257,6 +258,13 @@ func (cfg BlockChainConfig) WithNoAsyncFlush(on bool) *BlockChainConfig {
return &cfg
}
+// newBinaryTrieDB opens the sibling triedb that holds binary trie nodes
+// during the MPT-to-binary transition. It uses the same scheme and limits as
+// the main triedb but is forced into UBT mode.
+func newBinaryTrieDB(db ethdb.Database, cfg *BlockChainConfig) *triedb.Database {
+ return triedb.NewDatabase(db, cfg.triedbConfig(true))
+}
+
// triedbConfig derives the configures for trie database.
func (cfg *BlockChainConfig) triedbConfig(isUBT bool) *triedb.Config {
config := &triedb.Config{
@@ -323,6 +331,7 @@ type BlockChain struct {
lastWrite uint64 // Last block when the state was flushed
flushInterval atomic.Int64 // Time interval (processing time) after which to flush a state
triedb *triedb.Database // The database handler for maintaining trie nodes.
+ bintriedb *triedb.Database // Sibling triedb for binary trie nodes during the MPT-to-binary transition; nil if no UBT fork is configured or the chain is binary at genesis.
codedb *state.CodeDB // The database handler for maintaining contract codes.
txIndexer *txIndexer // Transaction indexer, might be nil if not enabled
@@ -382,16 +391,26 @@ func NewBlockChain(db ethdb.Database, genesis *Genesis, engine consensus.Engine,
if err != nil {
return nil, err
}
- triedb := triedb.NewDatabase(db, cfg.triedbConfig(enableVerkle))
+ mainTriedb := triedb.NewDatabase(db, cfg.triedbConfig(enableVerkle))
+
+ // Open a sibling binary trie database when the chain is configured for an
+ // MPT-to-binary transition (i.e. UBTTime is set and the chain did not start
+ // binary at genesis). The two databases run in parallel during the
+ // transition window: writes target the binary trie, reads fall through to
+ // the frozen MPT base resolved from the transition registry.
+ var bintriedb *triedb.Database
// Write the supplied genesis to the database if it has not been initialized
// yet. The corresponding chain config will be returned, either from the
// provided genesis or from the locally stored configuration if the genesis
// has already been initialized.
- chainConfig, genesisHash, compatErr, err := SetupGenesisBlockWithOverride(db, triedb, genesis, cfg.Overrides, cfg.VmConfig.Tracer)
+ chainConfig, genesisHash, compatErr, err := SetupGenesisBlockWithOverride(db, mainTriedb, genesis, cfg.Overrides, cfg.VmConfig.Tracer)
if err != nil {
return nil, err
}
+ if !enableVerkle && chainConfig.UBTTime != nil {
+ bintriedb = newBinaryTrieDB(db, cfg)
+ }
log.Info("")
log.Info(strings.Repeat("-", 153))
for _, line := range strings.Split(chainConfig.Description(), "\n") {
@@ -404,7 +423,8 @@ func NewBlockChain(db ethdb.Database, genesis *Genesis, engine consensus.Engine,
chainConfig: chainConfig,
cfg: cfg,
db: db,
- triedb: triedb,
+ triedb: mainTriedb,
+ bintriedb: bintriedb,
codedb: state.NewCodeDB(db),
triegc: prque.New[int64, common.Hash](nil),
chainmu: syncx.NewClosableMutex(),
@@ -1349,6 +1369,11 @@ func (bc *BlockChain) Stop() {
if err := bc.triedb.Journal(bc.CurrentBlock().Root); err != nil {
log.Info("Failed to journal in-memory trie nodes", "err", err)
}
+ if bc.bintriedb != nil {
+ if err := bc.bintriedb.Journal(bc.CurrentBlock().Root); err != nil {
+ log.Info("Failed to journal in-memory binary trie nodes", "err", err)
+ }
+ }
} else {
// Ensure the state of a recent block is also stored to disk before exiting.
// We're writing three different states to catch different restart scenarios:
@@ -1390,6 +1415,11 @@ func (bc *BlockChain) Stop() {
if err := bc.triedb.Close(); err != nil {
log.Error("Failed to close trie database", "err", err)
}
+ if bc.bintriedb != nil {
+ if err := bc.bintriedb.Close(); err != nil {
+ log.Error("Failed to close binary trie database", "err", err)
+ }
+ }
log.Info("Blockchain stopped")
}
@@ -2108,6 +2138,72 @@ type ExecuteConfig struct {
EnableWitnessStats bool
}
+// stateDatabase returns the appropriate state.Database for executing a block
+// with the given header against the supplied parent root. The routing is:
+//
+// - pre-UBT-fork blocks → MPTDatabase backed by bc.triedb.
+// - first UBT block (parent is pre-UBT) → transition UBTDatabase, with the
+// binary trie as primary store and the parent's MPT root as the frozen
+// base. The MPT triedb is provided for read-through during the transition.
+// - subsequent UBT blocks → if the registry still reports an active
+// transition, a transition UBTDatabase is built; otherwise (transition
+// ended, or chainConfig.UBTTransitionEndTime crossed) a plain UBTDatabase
+// is returned with the transition wrap disabled.
+func (bc *BlockChain) stateDatabase(parentRoot common.Hash, header *types.Header) (state.Database, error) {
+ if !bc.chainConfig.IsUBT(header.Number, header.Time) {
+ return state.NewMPTDatabase(bc.triedb, bc.codedb).WithSnapshot(bc.snaps), nil
+ }
+ // Past the configured transition end: pure binary, no wrap, no MPT base.
+ if !bc.chainConfig.UBTTransitionActive(header.Number, header.Time) {
+ return state.NewUBTDatabase(bc.bintriedbOrMain(), bc.codedb).WithTransitionTreeWrap(false), nil
+ }
+ // First UBT block: parent is pre-UBT; seed the transition with parent root.
+ parent := bc.GetHeaderByHash(header.ParentHash)
+ if parent != nil && !bc.chainConfig.IsUBT(parent.Number, parent.Time) {
+ return state.NewTransitionUBTDatabase(bc.bintriedbOrMain(), bc.triedb, bc.codedb, parentRoot), nil
+ }
+ // Subsequent UBT block while the transition is active: probe the registry
+ // to see whether a base root is still recorded.
+ return bc.probeTransitionDatabase(parentRoot)
+}
+
+// bintriedbOrMain returns bc.bintriedb when present, otherwise the main triedb.
+// Binary-at-genesis chains have no sibling binary triedb because the main
+// triedb is already in UBT mode.
+func (bc *BlockChain) bintriedbOrMain() *triedb.Database {
+ if bc.bintriedb != nil {
+ return bc.bintriedb
+ }
+ return bc.triedb
+}
+
+// probeTransitionDatabase reads the transition registry from the binary trie
+// at the given root and chooses between a transition-mode UBTDatabase (if
+// the registry still records a base root) and a plain UBTDatabase otherwise.
+func (bc *BlockChain) probeTransitionDatabase(root common.Hash) (state.Database, error) {
+ bindb := bc.bintriedbOrMain()
+ plain := state.NewUBTDatabase(bindb, bc.codedb)
+ reader, err := plain.StateReader(root)
+ if err != nil {
+ return nil, err
+ }
+ ts, err := overlay.LoadTransitionState(storageReaderFunc(reader.Storage))
+ if err != nil {
+ return nil, err
+ }
+ if ts == nil || ts.Transitioned() || ts.BaseRoot == (common.Hash{}) {
+ return plain, nil
+ }
+ return state.NewTransitionUBTDatabase(bindb, bc.triedb, bc.codedb, ts.BaseRoot), nil
+}
+
+// storageReaderFunc adapts a state-reader Storage method to overlay.StorageReader.
+type storageReaderFunc func(addr common.Address, slot common.Hash) (common.Hash, error)
+
+func (f storageReaderFunc) Storage(addr common.Address, slot common.Hash) (common.Hash, error) {
+ return f(addr, slot)
+}
+
// ProcessBlock executes and validates the given block. If there was no error
// it writes the block and associated state to database.
func (bc *BlockChain) ProcessBlock(ctx context.Context, parentRoot common.Hash, block *types.Block, config ExecuteConfig) (result *blockProcessingResult, blockEndErr error) {
@@ -2116,14 +2212,12 @@ func (bc *BlockChain) ProcessBlock(ctx context.Context, parentRoot common.Hash,
startTime = time.Now()
statedb *state.StateDB
interrupt atomic.Bool
- sdb state.Database
)
defer interrupt.Store(true) // terminate the prefetch at the end
- if bc.chainConfig.IsUBT(block.Number(), block.Time()) {
- sdb = state.NewUBTDatabase(bc.triedb, bc.codedb)
- } else {
- sdb = state.NewMPTDatabase(bc.triedb, bc.codedb).WithSnapshot(bc.snaps)
+ sdb, err := bc.stateDatabase(parentRoot, block.Header())
+ if err != nil {
+ return nil, err
}
// If prefetching is enabled, run that against the current state to pre-cache
// transactions and probabilistically some of the account/storage trie nodes.
diff --git a/core/blockchain_reader.go b/core/blockchain_reader.go
index 18afa9ce9d..c9c6671b39 100644
--- a/core/blockchain_reader.go
+++ b/core/blockchain_reader.go
@@ -421,27 +421,21 @@ func (bc *BlockChain) State() (*state.StateDB, error) {
// StateAt returns a new mutable state based on a particular point in time.
func (bc *BlockChain) StateAt(header *types.Header) (*state.StateDB, error) {
- if bc.chainConfig.IsUBT(header.Number, header.Time) {
- return state.New(header.Root, state.NewUBTDatabase(bc.triedb, bc.codedb))
+ db, err := bc.stateDatabase(header.Root, header)
+ if err != nil {
+ return nil, err
}
- return state.New(header.Root, state.NewMPTDatabase(bc.triedb, bc.codedb).WithSnapshot(bc.snaps))
+ return state.New(header.Root, db)
}
// StateAtForkBoundary returns a new mutable state based on the parent state
// and the given header, handling the transition across the UBT fork.
func (bc *BlockChain) StateAtForkBoundary(parent *types.Header, header *types.Header) (*state.StateDB, error) {
- // The parent is already in the UBT fork.
- if bc.chainConfig.IsUBT(parent.Number, parent.Time) {
- return state.New(parent.Root, state.NewUBTDatabase(bc.triedb, bc.codedb))
+ db, err := bc.stateDatabase(parent.Root, header)
+ if err != nil {
+ return nil, err
}
- // The current block is the first block in the UBT fork
- // (i.e., the parent is the last MPT block).
- if bc.chainConfig.IsUBT(header.Number, header.Time) {
- // TODO(gballet): register chain context if needed
- return state.New(parent.Root, state.NewUBTDatabase(bc.triedb, bc.codedb))
- }
- // Both the parent and current block are in the MPT fork.
- return state.New(parent.Root, state.NewMPTDatabase(bc.triedb, bc.codedb).WithSnapshot(bc.snaps))
+ return state.New(parent.Root, db)
}
// HistoricState returns a historic state specified by the given header.
diff --git a/core/chain_makers.go b/core/chain_makers.go
index 46cd98de61..aefae433ca 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -172,6 +172,14 @@ func (b *BlockGen) GetBalance(addr common.Address) *uint256.Int {
return b.statedb.GetBalance(addr)
}
+// GetState returns the storage slot value for the given address and key as
+// observed by the in-progress block generator. Useful in tests that need to
+// inspect system-contract slots written during block production (e.g. the
+// binary transition registry).
+func (b *BlockGen) GetState(addr common.Address, key common.Hash) common.Hash {
+ return b.statedb.GetState(addr, key)
+}
+
// AddUncheckedTx forcefully adds a transaction to the block without any validation.
//
// AddUncheckedTx will cause consensus failures when used during real
@@ -399,6 +407,13 @@ func GenerateChain(config *params.ChainConfig, parent *types.Block, engine conse
ProcessParentBlockHash(b.header.ParentHash, evm)
}
+ // On the first UBT block, deploy the binary transition registry and
+ // record the parent's MPT root as the frozen base root.
+ if config.IsUBT(b.header.Number, b.header.Time) && !config.IsUBT(parent.Number(), parent.Time()) {
+ InitializeBinaryTransitionRegistry(statedb)
+ WriteBinaryTransitionBaseRoot(statedb, parent.Root())
+ }
+
// Execute any user modifications to the block
if gen != nil {
gen(i, b)
diff --git a/core/genesis.go b/core/genesis.go
index d77ea10d8c..8095b4442a 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -276,10 +276,11 @@ func (e *GenesisMismatchError) Error() string {
// ChainOverrides contains the changes to chain config.
type ChainOverrides struct {
- OverrideOsaka *uint64
- OverrideBPO1 *uint64
- OverrideBPO2 *uint64
- OverrideUBT *uint64
+ OverrideOsaka *uint64
+ OverrideBPO1 *uint64
+ OverrideBPO2 *uint64
+ OverrideUBT *uint64
+ OverrideUBTTransitionEnd *uint64
}
// apply applies the chain overrides on the supplied chain config.
@@ -299,6 +300,9 @@ func (o *ChainOverrides) apply(cfg *params.ChainConfig) error {
if o.OverrideUBT != nil {
cfg.UBTTime = o.OverrideUBT
}
+ if o.OverrideUBTTransitionEnd != nil {
+ cfg.UBTTransitionEndTime = o.OverrideUBTTransitionEnd
+ }
return cfg.CheckConfigForkOrder()
}
diff --git a/core/overlay/state_transition.go b/core/overlay/state_transition.go
index afd2bab017..58680cae30 100644
--- a/core/overlay/state_transition.go
+++ b/core/overlay/state_transition.go
@@ -17,29 +17,39 @@
package overlay
import (
- "bytes"
- "encoding/gob"
-
"github.com/ethereum/go-ethereum/common"
- "github.com/ethereum/go-ethereum/core/rawdb"
- "github.com/ethereum/go-ethereum/ethdb"
- "github.com/ethereum/go-ethereum/log"
+ "github.com/ethereum/go-ethereum/params"
)
+// Storage slots used by the binary transition registry system contract at
+// params.BinaryTransitionRegistryAddress.
+var (
+ transitionStartedKey = common.Hash{}
+ conversionProgressAddressKey = common.BytesToHash([]byte{1})
+ conversionProgressSlotKey = common.BytesToHash([]byte{2})
+ conversionProgressStorageProcessed = common.BytesToHash([]byte{3})
+ transitionEndedKey = common.BytesToHash([]byte{4})
+ baseRootKey = common.BytesToHash([]byte{5})
+)
+
+// StorageReader is a minimal interface for reading contract storage slots.
+type StorageReader interface {
+ Storage(addr common.Address, slot common.Hash) (common.Hash, error)
+}
+
// TransitionState is a structure that holds the progress markers of the
// translation process.
type TransitionState struct {
- CurrentAccountAddress *common.Address // addresss of the last translated account
+ CurrentAccountAddress *common.Address // address of the last translated account
CurrentSlotHash common.Hash // hash of the last translated storage slot
- CurrentPreimageOffset int64 // next byte to read from the preimage file
Started, Ended bool
- // Mark whether the storage for an account has been processed. This is useful if the
- // maximum number of leaves of the conversion is reached before the whole storage is
- // processed.
+ // StorageProcessed marks whether the storage of the current account has
+ // been fully processed. Useful when the maximum number of leaves of the
+ // conversion is reached before the storage is exhausted.
StorageProcessed bool
- BaseRoot common.Hash // hash of the last read-only MPT base tree
+ BaseRoot common.Hash // frozen MPT base root captured at the fork block
}
// InTransition returns true if the translation process is in progress.
@@ -55,12 +65,11 @@ func (ts *TransitionState) Transitioned() bool {
// Copy returns a deep copy of the TransitionState object.
func (ts *TransitionState) Copy() *TransitionState {
ret := &TransitionState{
- Started: ts.Started,
- Ended: ts.Ended,
- CurrentSlotHash: ts.CurrentSlotHash,
- CurrentPreimageOffset: ts.CurrentPreimageOffset,
- StorageProcessed: ts.StorageProcessed,
- BaseRoot: ts.BaseRoot,
+ Started: ts.Started,
+ Ended: ts.Ended,
+ CurrentSlotHash: ts.CurrentSlotHash,
+ StorageProcessed: ts.StorageProcessed,
+ BaseRoot: ts.BaseRoot,
}
if ts.CurrentAccountAddress != nil {
addr := *ts.CurrentAccountAddress
@@ -69,38 +78,54 @@ func (ts *TransitionState) Copy() *TransitionState {
return ret
}
-// LoadTransitionState retrieves the Verkle transition state associated with
-// the given state root hash from the database.
-func LoadTransitionState(db ethdb.KeyValueReader, root common.Hash, isUBT bool) *TransitionState {
- var ts *TransitionState
-
- data, _ := rawdb.ReadVerkleTransitionState(db, root)
-
- // if a state could be read from the db, attempt to decode it
- if len(data) > 0 {
- var (
- newts TransitionState
- buf = bytes.NewBuffer(data[:])
- dec = gob.NewDecoder(buf)
- )
- // Decode transition state
- err := dec.Decode(&newts)
- if err != nil {
- log.Error("failed to decode transition state", "err", err)
- return nil
- }
- ts = &newts
+// IsTransitionActive checks whether the binary transition registry has been
+// initialised by reading slot 0 (started) from the system contract.
+func IsTransitionActive(reader StorageReader) bool {
+ val, err := reader.Storage(params.BinaryTransitionRegistryAddress, transitionStartedKey)
+ if err != nil {
+ return false
}
-
- // Fallback that should only happen before the transition
- if ts == nil {
- // Initialize the first transition state, with the "ended"
- // field set to true if the database was created
- // as a verkle database.
- log.Debug("no transition state found, starting fresh", "verkle", isUBT)
-
- // Start with a fresh state
- ts = &TransitionState{Ended: isUBT}
- }
- return ts
+ return val != (common.Hash{})
+}
+
+// LoadTransitionState reads the full transition state from the binary
+// transition registry system contract storage. Returns nil when the
+// registry has not been initialised (i.e. the chain has not yet reached the
+// UBT fork block).
+func LoadTransitionState(reader StorageReader) (*TransitionState, error) {
+ started, err := reader.Storage(params.BinaryTransitionRegistryAddress, transitionStartedKey)
+ if err != nil {
+ return nil, err
+ }
+ if started == (common.Hash{}) {
+ return nil, nil
+ }
+
+ ended, _ := reader.Storage(params.BinaryTransitionRegistryAddress, transitionEndedKey)
+ baseRoot, _ := reader.Storage(params.BinaryTransitionRegistryAddress, baseRootKey)
+
+ var currentAddr *common.Address
+ addrVal, _ := reader.Storage(params.BinaryTransitionRegistryAddress, conversionProgressAddressKey)
+ if addrVal != (common.Hash{}) {
+ addr := common.BytesToAddress(addrVal.Bytes())
+ currentAddr = &addr
+ }
+
+ slotHash, err := reader.Storage(params.BinaryTransitionRegistryAddress, conversionProgressSlotKey)
+ if err != nil {
+ return nil, err
+ }
+ storageProcessed, err := reader.Storage(params.BinaryTransitionRegistryAddress, conversionProgressStorageProcessed)
+ if err != nil {
+ return nil, err
+ }
+
+ return &TransitionState{
+ Started: true,
+ Ended: ended != (common.Hash{}),
+ BaseRoot: baseRoot,
+ CurrentAccountAddress: currentAddr,
+ CurrentSlotHash: slotHash,
+ StorageProcessed: storageProcessed != (common.Hash{}),
+ }, nil
}
diff --git a/core/rawdb/accessors_overlay.go b/core/rawdb/accessors_overlay.go
deleted file mode 100644
index 364cc889d1..0000000000
--- a/core/rawdb/accessors_overlay.go
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2025 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library 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 Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see .
-
-package rawdb
-
-import (
- "github.com/ethereum/go-ethereum/common"
- "github.com/ethereum/go-ethereum/ethdb"
-)
-
-func ReadVerkleTransitionState(db ethdb.KeyValueReader, hash common.Hash) ([]byte, error) {
- return db.Get(transitionStateKey(hash))
-}
-
-func WriteVerkleTransitionState(db ethdb.KeyValueWriter, hash common.Hash, state []byte) error {
- return db.Put(transitionStateKey(hash), state)
-}
diff --git a/core/rawdb/database.go b/core/rawdb/database.go
index 39e1a64e5a..ccf2eace65 100644
--- a/core/rawdb/database.go
+++ b/core/rawdb/database.go
@@ -691,7 +691,7 @@ var knownMetadataKeys = [][]byte{
snapshotGeneratorKey, snapshotRecoveryKey, txIndexTailKey, fastTxLookupLimitKey,
uncleanShutdownKey, badBlockKey, transitionStatusKey, skeletonSyncStatusKey,
persistentStateIDKey, trieJournalKey, snapshotSyncStatusKey, snapSyncStatusFlagKey,
- filterMapsRangeKey, headStateHistoryIndexKey, headTrienodeHistoryIndexKey, VerkleTransitionStatePrefix,
+ filterMapsRangeKey, headStateHistoryIndexKey, headTrienodeHistoryIndexKey,
}
// printChainMetadata prints out chain metadata to stderr.
diff --git a/core/rawdb/schema.go b/core/rawdb/schema.go
index 54c76143b4..a5ebb961f7 100644
--- a/core/rawdb/schema.go
+++ b/core/rawdb/schema.go
@@ -165,9 +165,6 @@ var (
preimageCounter = metrics.NewRegisteredCounter("db/preimage/total", nil)
preimageHitsCounter = metrics.NewRegisteredCounter("db/preimage/hits", nil)
preimageMissCounter = metrics.NewRegisteredCounter("db/preimage/miss", nil)
-
- // Verkle transition information
- VerkleTransitionStatePrefix = []byte("verkle-transition-state-")
)
// LegacyTxLookupEntry is the legacy TxLookupEntry definition with some unnecessary
@@ -460,8 +457,3 @@ func trienodeHistoryIndexBlockKey(addressHash common.Hash, path []byte, blockID
return out
}
-
-// transitionStateKey = transitionStatusKey + hash
-func transitionStateKey(hash common.Hash) []byte {
- return append(VerkleTransitionStatePrefix, hash.Bytes()...)
-}
diff --git a/core/state/database_ubt.go b/core/state/database_ubt.go
index 718d93df87..287d683a8f 100644
--- a/core/state/database_ubt.go
+++ b/core/state/database_ubt.go
@@ -17,18 +17,25 @@
package state
import (
+ "errors"
+
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/rawdb"
+ "github.com/ethereum/go-ethereum/core/types"
+ "github.com/ethereum/go-ethereum/crypto"
+ "github.com/ethereum/go-ethereum/trie"
"github.com/ethereum/go-ethereum/trie/bintrie"
+ "github.com/ethereum/go-ethereum/trie/transitiontrie"
"github.com/ethereum/go-ethereum/triedb"
)
// UBTDatabase is an implementation of Database interface for Unified Binary Trie.
-// It provides the same functionality as MPTDatabase but uses unified binary
-// trie for state hashing instead of Merkle Patricia Tries.
type UBTDatabase struct {
- triedb *triedb.Database
- codedb *CodeDB
+ triedb *triedb.Database
+ mpttriedb *triedb.Database
+ codedb *CodeDB
+ baseRoot common.Hash
+ wrapInTransitionTrie bool
}
// Type returns Binary, indicating this database is backed by a Universal Binary Trie.
@@ -40,11 +47,38 @@ func NewUBTDatabase(triedb *triedb.Database, codedb *CodeDB) *UBTDatabase {
codedb = NewCodeDB(triedb.Disk())
}
return &UBTDatabase{
- triedb: triedb,
- codedb: codedb,
+ triedb: triedb,
+ codedb: codedb,
+ wrapInTransitionTrie: true,
}
}
+// NewTransitionUBTDatabase creates a UBTDatabase for the active MPT-to-binary
+// transition window. The binary trie is the primary store; reads fall through
+// to the frozen MPT at baseRoot via the supplied mpttriedb, and writes go
+// only to the binary trie.
+func NewTransitionUBTDatabase(bintriedb, mpttriedb *triedb.Database, codedb *CodeDB, baseRoot common.Hash) *UBTDatabase {
+ if codedb == nil {
+ codedb = NewCodeDB(bintriedb.Disk())
+ }
+ return &UBTDatabase{
+ triedb: bintriedb,
+ mpttriedb: mpttriedb,
+ codedb: codedb,
+ baseRoot: baseRoot,
+ wrapInTransitionTrie: true,
+ }
+}
+
+// WithTransitionTreeWrap toggles whether reads at this database are wrapped
+// in a TransitionTrie. Setting it to false disables the wrap regardless of
+// the registry state and is intended for callers that have already crossed
+// the configured UBTTransitionEndTime.
+func (db *UBTDatabase) WithTransitionTreeWrap(wrap bool) *UBTDatabase {
+ db.wrapInTransitionTrie = wrap
+ return db
+}
+
// StateReader returns a state reader associated with the specified state root.
func (db *UBTDatabase) StateReader(stateRoot common.Hash) (StateReader, error) {
var readers []StateReader
@@ -61,7 +95,7 @@ func (db *UBTDatabase) StateReader(stateRoot common.Hash) (StateReader, error) {
}
// Configure the trie reader, which is expected to be available as the
// gatekeeper unless the state is corrupted.
- tr, err := newUBTTrieReader(stateRoot, db.triedb)
+ tr, err := newUBTTrieReader(stateRoot, db.triedb, db.mpttriedb, db.wrapInTransitionTrie)
if err != nil {
return nil, err
}
@@ -96,13 +130,30 @@ func (db *UBTDatabase) ReadersWithCacheStats(stateRoot common.Hash) (Reader, Rea
// OpenTrie opens the main account trie at a specific root hash.
func (db *UBTDatabase) OpenTrie(root common.Hash) (Trie, error) {
- return bintrie.NewBinaryTrie(root, db.triedb)
+ bt, err := bintrie.NewBinaryTrie(root, db.triedb)
+ if err != nil {
+ return nil, err
+ }
+ if db.mpttriedb == nil || db.baseRoot == (common.Hash{}) {
+ return transitiontrie.NewTransitionTrie(nil, bt, false), nil
+ }
+ base, err := trie.NewStateTrie(trie.StateTrieID(db.baseRoot), db.mpttriedb)
+ if err != nil {
+ return nil, err
+ }
+ return transitiontrie.NewTransitionTrie(base, bt, false), nil
}
-// OpenStorageTrie opens the storage trie of an account. In binary trie mode,
-// all state objects share one unified trie, so the main trie is returned.
+// OpenStorageTrie opens the storage trie of an account. In binary trie mode
+// the unified trie carries all state, so the main trie is reused.
func (db *UBTDatabase) OpenStorageTrie(stateRoot common.Hash, address common.Address, root common.Hash, self Trie) (Trie, error) {
- return self, nil
+ if self != nil && self.IsUBT() {
+ return self, nil
+ }
+ if db.mpttriedb == nil {
+ return nil, errors.New("no MPT trie database available for storage trie outside the transition window")
+ }
+ return trie.NewStateTrie(trie.StorageTrieID(stateRoot, crypto.Keccak256Hash(address.Bytes()), root), db.mpttriedb)
}
// TrieDB retrieves any intermediate trie-node caching layer.
@@ -128,10 +179,17 @@ func (db *UBTDatabase) Commit(update *StateUpdate) error {
return err
}
}
+ // On the first transition block, the originRoot is the MPT base root,
+ // but the binary trie's parent state is empty. Substitute the empty
+ // binary hash so triedb.Update doesn't reject the mismatch.
+ originRoot := update.OriginRoot
+ if db.mpttriedb != nil && originRoot == db.baseRoot {
+ originRoot = types.EmptyBinaryHash
+ }
// Encode the state mutations in the UBT format
accounts, accountOrigin, storages, storageOrigin := update.EncodeUBTState()
- return db.triedb.Update(update.Root, update.OriginRoot, update.BlockNumber, update.Nodes, &triedb.StateSet{
+ return db.triedb.Update(update.Root, originRoot, update.BlockNumber, update.Nodes, &triedb.StateSet{
Accounts: accounts,
AccountsOrigin: accountOrigin,
Storages: storages,
diff --git a/core/state/reader.go b/core/state/reader.go
index 5df0acbb9b..140dbc3b60 100644
--- a/core/state/reader.go
+++ b/core/state/reader.go
@@ -252,46 +252,57 @@ type ubtTrieReader struct {
lock sync.Mutex // Lock for protecting concurrent read
}
+// binTrieStorageReader adapts a *bintrie.BinaryTrie to overlay.StorageReader
+// so the transition state can be loaded directly from the binary trie at a
+// specific state root.
+type binTrieStorageReader struct {
+ tr *bintrie.BinaryTrie
+}
+
+func (r *binTrieStorageReader) Storage(addr common.Address, slot common.Hash) (common.Hash, error) {
+ val, err := r.tr.GetStorage(addr, slot.Bytes())
+ if err != nil {
+ return common.Hash{}, err
+ }
+ var out common.Hash
+ out.SetBytes(val)
+ return out, nil
+}
+
// newUBTTrieReader constructs a Unified-binary-trie reader of the specific state.
// An error will be returned if the associated trie specified by root is not existent.
-func newUBTTrieReader(root common.Hash, db *triedb.Database) (*ubtTrieReader, error) {
- binTrie, binErr := bintrie.NewBinaryTrie(root, db)
- if binErr != nil {
- return nil, binErr
+//
+// When wrapInTransitionTrie is true, reads fall through to the frozen MPT
+// base whenever the transition registry has captured a non-zero base root
+// in slot 5 and an MPT triedb is available. When wrapInTransitionTrie is
+// false, the MPT base is never consulted regardless of registry state.
+//
+// Both branches still build a TransitionTrie because *bintrie.BinaryTrie
+// cannot satisfy the state.Trie interface directly (import cycle between
+// trie and trie/bintrie). When wrap is false the base argument is nil and
+// the wrapper degenerates to a passthrough.
+func newUBTTrieReader(root common.Hash, bindb *triedb.Database, mptdb *triedb.Database, wrapInTransitionTrie bool) (*ubtTrieReader, error) {
+ binTrie, err := bintrie.NewBinaryTrie(root, bindb)
+ if err != nil {
+ return nil, err
}
- // Based on the transition status, determine if the overlay
- // tree needs to be created, or if a single, target tree is
- // to be picked.
- var (
- tr Trie
- ts = overlay.LoadTransitionState(db.Disk(), root, true)
- )
- if ts.InTransition() {
- mpt, err := trie.NewStateTrie(trie.StateTrieID(ts.BaseRoot), db)
+ var base *trie.StateTrie
+ if wrapInTransitionTrie && mptdb != nil {
+ ts, err := overlay.LoadTransitionState(&binTrieStorageReader{tr: binTrie})
if err != nil {
return nil, err
}
- tr = transitiontrie.NewTransitionTrie(mpt, binTrie, false)
- } else {
- // HACK: Use TransitionTrie with nil base as a wrapper to make BinaryTrie
- // satisfy the Trie interface. This works around the import cycle between
- // trie and trie/bintrie packages.
- //
- // TODO: In future PRs, refactor the package structure to avoid this hack:
- // - Option 1: Move common interfaces (Trie, NodeIterator) to a separate
- // package that both trie and trie/bintrie can import
- // - Option 2: Create a factory function in the trie package that returns
- // BinaryTrie as a Trie interface without direct import
- // - Option 3: Move BinaryTrie to the main trie package
- //
- // The current approach works but adds unnecessary overhead and complexity
- // by using TransitionTrie when there's no actual transition happening.
- tr = transitiontrie.NewTransitionTrie(nil, binTrie, false)
+ if ts != nil && ts.BaseRoot != (common.Hash{}) {
+ base, err = trie.NewStateTrie(trie.StateTrieID(ts.BaseRoot), mptdb)
+ if err != nil {
+ return nil, err
+ }
+ }
}
return &ubtTrieReader{
root: root,
- db: db,
- tr: tr,
+ db: bindb,
+ tr: transitiontrie.NewTransitionTrie(base, binTrie, false),
}, nil
}
diff --git a/core/state_processor.go b/core/state_processor.go
index 54ebbd047b..c2c52402e7 100644
--- a/core/state_processor.go
+++ b/core/state_processor.go
@@ -96,6 +96,17 @@ func (p *StateProcessor) Process(ctx context.Context, block *types.Block, stated
if config.IsPrague(block.Number(), block.Time()) || config.IsUBT(block.Number(), block.Time()) {
ProcessParentBlockHash(block.ParentHash(), evm)
}
+ // On the first block after the UBT activation, deploy the binary
+ // transition registry system contract and capture the frozen MPT base
+ // root in slot 5. The registry is what every subsequent block reads to
+ // reconstruct the transition state.
+ if config.IsUBT(block.Number(), block.Time()) {
+ parent := p.chain.GetHeaderByHash(block.ParentHash())
+ if parent != nil && !config.IsUBT(parent.Number, parent.Time) {
+ InitializeBinaryTransitionRegistry(statedb)
+ WriteBinaryTransitionBaseRoot(statedb, parent.Root)
+ }
+ }
// Iterate over and process the individual transactions
for i, tx := range block.Transactions() {
diff --git a/core/transition_registry.go b/core/transition_registry.go
new file mode 100644
index 0000000000..5dff348f00
--- /dev/null
+++ b/core/transition_registry.go
@@ -0,0 +1,62 @@
+// Copyright 2026 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package core
+
+import (
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/core/state"
+ "github.com/ethereum/go-ethereum/core/tracing"
+ "github.com/ethereum/go-ethereum/params"
+)
+
+// transitionStatusByteCode is a minimal contract that returns a single 32-byte
+// storage slot to the caller. CALLDATALOAD picks the slot index from the call
+// input and SLOAD reads the value, which is then returned as a 32-byte word.
+var transitionStatusByteCode = []byte{
+ 0x60, 0x00, // PUSH1 0
+ 0x35, // CALLDATALOAD (slot index)
+ 0x54, // SLOAD
+ 0x60, 0x00, // PUSH1 0
+ 0x52, // MSTORE
+ 0x60, 0x20, // PUSH1 32
+ 0x60, 0x00, // PUSH1 0
+ 0xf3, // RETURN
+}
+
+// transitionRegistryBaseRootSlot is slot 5 of the transition registry, where
+// the frozen MPT base root is stored. The slot indices match those decoded by
+// overlay.LoadTransitionState; the layout is intentionally kept private to
+// the core package so external callers go through these helpers.
+var transitionRegistryBaseRootSlot = common.BytesToHash([]byte{5})
+
+// InitializeBinaryTransitionRegistry deploys the binary transition registry
+// system contract and marks the transition as started by writing 1 into slot
+// 0. It must be called exactly once, on the first block after the UBT
+// activation.
+func InitializeBinaryTransitionRegistry(statedb *state.StateDB) {
+ statedb.SetCode(params.BinaryTransitionRegistryAddress, transitionStatusByteCode, tracing.CodeChangeUnspecified)
+ statedb.SetNonce(params.BinaryTransitionRegistryAddress, 1, tracing.NonceChangeUnspecified)
+ statedb.SetState(params.BinaryTransitionRegistryAddress, common.Hash{}, common.Hash{1})
+}
+
+// WriteBinaryTransitionBaseRoot records the frozen MPT base root in slot 5 of
+// the transition registry. This must be called on the first UBT block, right
+// after InitializeBinaryTransitionRegistry, with the parent block's state
+// root.
+func WriteBinaryTransitionBaseRoot(statedb *state.StateDB, baseRoot common.Hash) {
+ statedb.SetState(params.BinaryTransitionRegistryAddress, transitionRegistryBaseRootSlot, baseRoot)
+}
diff --git a/miner/worker.go b/miner/worker.go
index 42e3695025..892f3ced30 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -335,6 +335,13 @@ func (miner *Miner) prepareWork(ctx context.Context, genParams *generateParams,
if miner.chainConfig.IsPrague(header.Number, header.Time) {
core.ProcessParentBlockHash(header.ParentHash, env.evm)
}
+ // Deploy the binary transition registry on the first UBT block and seed
+ // it with the parent's MPT root. Subsequent blocks read the registry to
+ // reconstruct the transition state.
+ if miner.chainConfig.IsUBT(header.Number, header.Time) && !miner.chainConfig.IsUBT(parent.Number, parent.Time) {
+ core.InitializeBinaryTransitionRegistry(env.state)
+ core.WriteBinaryTransitionBaseRoot(env.state, parent.Root)
+ }
return env, nil
}
diff --git a/params/config.go b/params/config.go
index 17508cbf27..f02d239ad5 100644
--- a/params/config.go
+++ b/params/config.go
@@ -468,6 +468,11 @@ type ChainConfig struct {
AmsterdamTime *uint64 `json:"amsterdamTime,omitempty"` // Amsterdam switch time (nil = no fork, 0 = already on amsterdam)
UBTTime *uint64 `json:"ubtTime,omitempty"` // UBT switch time (nil = no fork, 0 = already on UBT)
+ // UBTTransitionEndTime is the timestamp at which the MPT-to-binary
+ // transition tree is no longer applied. Mirrors the threshold semantics
+ // of TerminalTotalDifficulty.
+ UBTTransitionEndTime *uint64 `json:"ubtTransitionEndTime,omitempty"`
+
// TerminalTotalDifficulty is the amount of total difficulty reached by
// the network that triggers the consensus upgrade.
TerminalTotalDifficulty *big.Int `json:"terminalTotalDifficulty,omitempty"`
@@ -598,6 +603,9 @@ func (c *ChainConfig) String() string {
if c.UBTTime != nil {
result += fmt.Sprintf(", UBTTime: %v", *c.UBTTime)
}
+ if c.UBTTransitionEndTime != nil {
+ result += fmt.Sprintf(", UBTTransitionEndTime: %v", *c.UBTTransitionEndTime)
+ }
result += "}"
return result
}
@@ -693,6 +701,9 @@ func (c *ChainConfig) Description() string {
if c.UBTTime != nil {
banner += fmt.Sprintf(" - UBT: @%-10v blob: (%s)\n", *c.UBTTime, c.BlobScheduleConfig.UBT)
}
+ if c.UBTTransitionEndTime != nil {
+ banner += fmt.Sprintf(" - UBT transition tree ends: @%-10v\n", *c.UBTTransitionEndTime)
+ }
banner += fmt.Sprintf("\nAll fork specifications can be found at https://ethereum.github.io/execution-specs/src/ethereum/forks/\n")
return banner
}
@@ -871,16 +882,18 @@ func (c *ChainConfig) IsUBT(num *big.Int, time uint64) bool {
return c.IsLondon(num) && isTimestampForked(c.UBTTime, time)
}
-// IsUBTGenesis checks whether the verkle fork is activated at the genesis block.
-//
-// Verkle mode is considered enabled if the verkle fork time is configured,
-// regardless of whether the local time has surpassed the fork activation time.
-// This is a temporary workaround for verkle devnet testing, where verkle is
-// activated at genesis, and the configured activation date has already passed.
-//
-// In production networks (mainnet and public testnets), verkle activation
-// always occurs after the genesis block, making this function irrelevant in
-// those cases.
+// UBTTransitionActive reports whether state access at the given block number
+// and time should still be wrapped in a TransitionTrie (binary overlay on top
+// of the frozen MPT base). It is true when UBT is active and either no end
+// time is configured or the block is still before the configured end time.
+func (c *ChainConfig) UBTTransitionActive(num *big.Int, time uint64) bool {
+ if !c.IsUBT(num, time) {
+ return false
+ }
+ return c.UBTTransitionEndTime == nil || time < *c.UBTTransitionEndTime
+}
+
+// IsUBTGenesis checks whether the UBT fork is activated at the genesis block.
func (c *ChainConfig) IsUBTGenesis() bool {
return c.EnableUBTAtGenesis
}
diff --git a/params/protocol_params.go b/params/protocol_params.go
index 9da275c486..44a8cc89c3 100644
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -222,6 +222,10 @@ var (
// EIP-7251 - Increase the MAX_EFFECTIVE_BALANCE
ConsolidationQueueAddress = common.HexToAddress("0x0000BBdDc7CE488642fb579F8B00f3a590007251")
ConsolidationQueueCode = common.FromHex("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")
+
+ // BinaryTransitionRegistryAddress is the system contract that exposes the
+ // MPT-to-binary transition state via storage slots.
+ BinaryTransitionRegistryAddress = common.HexToAddress("0x1622162216221622162216221622162216221622")
)
// System log events.