feat(protocol): remove the ETHDeposit feature completely (#16638)

packages/protocol/contracts/L1/TaikoData.sol

@@ -30,22 +30,8 @@ library TaikoData {
         // The amount of Taiko token as a prover liveness bond
         uint96 livenessBond;
         // ---------------------------------------------------------------------
-        // Group 4: ETH deposit related configs
+        // Group 4: Cross-chain sync
         // ---------------------------------------------------------------------
-        // The size of the ETH deposit ring buffer.
-        uint256 ethDepositRingBufferSize;
-        // The minimum number of ETH deposits allowed per block.
-        uint64 ethDepositMinCountPerBlock;
-        // The maximum number of ETH deposits allowed per block.
-        uint64 ethDepositMaxCountPerBlock;
-        // The minimum amount of ETH required for a deposit.
-        uint96 ethDepositMinAmount;
-        // The maximum amount of ETH allowed for a deposit.
-        uint96 ethDepositMaxAmount;
-        // The gas cost for processing an ETH deposit.
-        uint256 ethDepositGas;
-        // The maximum fee allowed for an ETH deposit.
-        uint256 ethDepositMaxFee;
         // The max number of L2 blocks that can stay unsynced on L1 (a value of zero disables
         // syncing)
         uint8 blockSyncThreshold;
@@ -148,17 +134,17 @@ library TaikoData {
     struct SlotA {
         uint64 genesisHeight;
         uint64 genesisTimestamp;
-        uint64 numEthDeposits;
-        uint64 nextEthDepositToProcess;
+        uint64 __reservedA1;
+        uint64 __reservedA2;
     }
 
     struct SlotB {
         uint64 numBlocks;
         uint64 lastVerifiedBlockId;
         bool provingPaused;
-        uint8 __reserved1;
-        uint16 __reserved2;
-        uint32 __reserved3;
+        uint8 __reservedB1;
+        uint16 __reservedB2;
+        uint32 __reservedB3;
         uint64 lastUnpausedAt;
     }
 
@@ -174,7 +160,7 @@ library TaikoData {
                 => mapping(uint32 transitionId => TransitionState ts)
             ) transitions;
         // Ring buffer for Ether deposits
-        mapping(uint256 depositId_mod_ethDepositRingBufferSize => uint256 depositAmount) ethDeposits;
+        bytes32 __reserve1;
         SlotA slotA; // slot 5
         SlotB slotB; // slot 6
         uint256[44] __gap;

packages/protocol/contracts/L1/TaikoErrors.sol

@@ -17,7 +17,6 @@ abstract contract TaikoErrors {
     error L1_BLOCK_MISMATCH();
     error L1_INVALID_BLOCK_ID();
     error L1_INVALID_CONFIG();
-    error L1_INVALID_ETH_DEPOSIT();
     error L1_INVALID_HOOK();
     error L1_INVALID_PARAM();
     error L1_INVALID_PAUSE_STATUS();

packages/protocol/contracts/L1/TaikoL1.sol

@@ -34,7 +34,7 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
         LibVerifying.emitEventForClient(state);
     }
 
-    /// @dev Fallback function to receive Ether from Hooks
+    /// @dev Allows for receiving Ether from Hooks
     receive() external payable {
         if (!_inNonReentrant()) revert L1_RECEIVE_DISABLED();
     }
@@ -55,6 +55,16 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
         LibVerifying.init(state, getConfig(), _genesisBlockHash);
     }
 
+    function init2() external reinitializer(2) {
+        // reset some previously used slots for future reuse
+        state.slotA.__reservedA1 = 0;
+        state.slotA.__reservedA2 = 0;
+        state.slotB.__reservedB1 = 0;
+        state.slotB.__reservedB2 = 0;
+        state.slotB.__reservedB3 = 0;
+        state.__reserve1 = 0;
+    }
+
     /// @inheritdoc ITaikoL1
     function proposeBlock(
         bytes calldata _params,
@@ -68,7 +78,6 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
         returns (TaikoData.BlockMetadata memory meta_, TaikoData.EthDeposit[] memory deposits_)
     {
         TaikoData.Config memory config = getConfig();
-
         (meta_, deposits_) = LibProposing.proposeBlock(state, config, this, _params, _txList);
 
         if (!state.slotB.provingPaused) {
@@ -120,26 +129,12 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
         LibProving.pauseProving(state, _pause);
     }
 
-    /// @notice Deposits Ether to Layer 2.
-    /// @param _recipient Address of the recipient for the deposited Ether on
-    /// Layer 2.
-    function depositEtherToL2(address _recipient) external payable whenNotPaused nonReentrant {
-        LibDepositing.depositEtherToL2(state, getConfig(), this, _recipient);
-    }
-
     /// @inheritdoc EssentialContract
     function unpause() public override {
         super.unpause(); // permission checked inside
         state.slotB.lastUnpausedAt = uint64(block.timestamp);
     }
 
-    /// @notice Checks if Ether deposit is allowed for Layer 2.
-    /// @param _amount Amount of Ether to be deposited.
-    /// @return true if Ether deposit is allowed, false otherwise.
-    function canDepositEthToL2(uint256 _amount) public view returns (bool) {
-        return LibDepositing.canDepositEthToL2(state, getConfig(), _amount);
-    }
-
     /// @notice Gets the details of a block.
     /// @param _blockId Index of the block.
     /// @return blk_ The block.
@@ -203,14 +198,6 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
             // Taiko blocks proposed per Ethereum block is smaller than 1.
             blockMaxGasLimit: 240_000_000,
             livenessBond: 250e18, // 250 Taiko token
-            // ETH deposit related.
-            ethDepositRingBufferSize: 1024,
-            ethDepositMinCountPerBlock: 8,
-            ethDepositMaxCountPerBlock: 32,
-            ethDepositMinAmount: 1 ether,
-            ethDepositMaxAmount: 10_000 ether,
-            ethDepositGas: 21_000,
-            ethDepositMaxFee: 1e17, //0.1 ether,
             blockSyncThreshold: 16
         });
     }

packages/protocol/contracts/L1/libs/LibProposing.sol

@@ -2,16 +2,21 @@
 pragma solidity 0.8.24;
 
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "../../common/IAddressResolver.sol";
+import "../../libs/LibAddress.sol";
 import "../hooks/IHook.sol";
 import "../tiers/ITierProvider.sol";
-import "./LibDepositing.sol";
 
 /// @title LibProposing
 /// @notice A library for handling block proposals in the Taiko protocol.
 /// @custom:security-contact [email protected]
 library LibProposing {
     using LibAddress for address;
 
+    // = keccak256(abi.encode(new TaikoData.EthDeposit[](0)))
+    bytes32 private constant _EMPTY_ETH_DEPOSIT_HASH =
+        0x569e75fc77c1a856f6daaf9e69d8a9566ca34aa47f9133711ce065a571af0cfd;
+
     // Warning: Any events defined here must also be defined in TaikoEvents.sol.
     /// @notice Emitted when a block is proposed.
     /// @param blockId The ID of the proposed block.
@@ -46,8 +51,6 @@ library LibProposing {
     /// @param _data Encoded data bytes containing the block params.
     /// @param _txList Transaction list bytes (if not blob).
     /// @return meta_ The constructed block's metadata.
-    /// @return deposits_ The EthDeposit array about processed deposits in this proposed
-    /// block.
     function proposeBlock(
         TaikoData.State storage _state,
         TaikoData.Config memory _config,
@@ -92,10 +95,6 @@ library LibProposing {
             revert L1_UNEXPECTED_PARENT();
         }
 
-        // Each transaction must handle a specific quantity of L1-to-L2
-        // Ether deposits.
-        deposits_ = LibDepositing.processDeposits(_state, _config, params.coinbase);
-
         // Initialize metadata to compute a metaHash, which forms a part of
         // the block data to be stored on-chain for future integrity checks.
         // If we choose to persist all data fields in the metadata, it will
@@ -106,7 +105,7 @@ library LibProposing {
                 difficulty: 0, // to be initialized below
                 blobHash: 0, // to be initialized below
                 extraData: params.extraData,
-                depositsHash: keccak256(abi.encode(deposits_)),
+                depositsHash: _EMPTY_ETH_DEPOSIT_HASH,
                 coinbase: params.coinbase,
                 id: b.numBlocks,
                 gasLimit: _config.blockMaxGasLimit,
@@ -213,6 +212,7 @@ library LibProposing {
             }
         }
 
+        deposits_ = new TaikoData.EthDeposit[](0);
         emit BlockProposed({
             blockId: blk.blockId,
             assignedProver: blk.assignedProver,

packages/protocol/contracts/L1/libs/LibProving.sol

@@ -71,7 +71,7 @@ library LibProving {
     /// @notice Pauses or unpauses the proving process.
     /// @param _state Current TaikoData.State.
     /// @param _pause The pause status.
-    function pauseProving(TaikoData.State storage _state, bool _pause) external {
+    function pauseProving(TaikoData.State storage _state, bool _pause) internal {
         if (_state.slotB.provingPaused == _pause) revert L1_INVALID_PAUSE_STATUS();
         _state.slotB.provingPaused = _pause;
 

packages/protocol/contracts/L1/libs/LibUtils.sol

@@ -29,7 +29,7 @@ library LibUtils {
         uint64 _blockId,
         bytes32 _parentHash
     )
-        external
+        internal
         view
         returns (TaikoData.TransitionState storage)
     {
@@ -57,7 +57,7 @@ library LibUtils {
         TaikoData.Config memory _config,
         uint64 _blockId
     )
-        external
+        internal
         view
         returns (TaikoData.Block storage blk_, uint64 slot_)
     {