[General] Where and How to use these values, in system tx?

[cuiweixie]

Discussion Topic

https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts-bedrock/src/L2/L1Block.sol#L95-L114

    /// @custom:legacy
    /// @notice Updates the L1 block values.
    /// @param _number         L1 blocknumber.
    /// @param _timestamp      L1 timestamp.
    /// @param _basefee        L1 basefee.
    /// @param _hash           L1 blockhash.
    /// @param _sequenceNumber Number of L2 blocks since epoch start.
    /// @param _batcherHash    Versioned hash to authenticate batcher by.
    /// @param _l1FeeOverhead  L1 fee overhead.
    /// @param _l1FeeScalar    L1 fee scalar.

these value is seted by first tx(system tx) in block.
I have find in the code, fee is used by op-geth in fee stuffs. But I cann't find where and how the other values is being used.
can you tell me?

[opfocus]

https://specs.optimism.io/protocol/derivation.html#batch-format please check if this content helpful

[Chomtana]

These values come from L1

For L1 fee overhead and scalar, they are manually set by the chain operator in the SystemConfig contract

_basefee, _l1FeeOverhead and _l1FeeScalar are together used to determine a portion of gas fee on L2 according to https://docs.optimism.io/stack/transactions/fees

If you want to use these value in your contract (most use case is to access L1 block hash) you can query it from the predeployed L1Block contract on L2