"""

    Read a genesis configuration from the given JSON file path.

    The genesis file should be present in the `assets` directory.

    """

    genesis_path = f"assets/{genesis_file}"

    genesis_bytes = pkgutil.get_data("ethereum", genesis_path)

    if genesis_bytes is None:

        raise Exception(f"Unable to read genesis from `{genesis_path}`")

    genesis_data = json.loads(genesis_bytes.decode())

    return GenesisConfiguration(

        chain_id=U64(genesis_data["config"]["chainId"]),

        difficulty=hex_to_uint(genesis_data["difficulty"]),

        extra_data=hex_to_bytes(genesis_data["extraData"]),

        gas_limit=hex_to_uint(genesis_data["gasLimit"]),

        nonce=hex_to_bytes8(genesis_data["nonce"]),

        timestamp=hex_or_base_10_str_to_u256(genesis_data["timestamp"]),

        initial_accounts=genesis_data["alloc"],

    )

    """

    Convert a string in either hexadecimal or base-10 to a `U256`.

    """

    if balance.startswith("0x"):

        return hex_to_u256(balance)

    else:

        return U256(int(balance))

    """

    Adds the genesis block to an empty blockchain.

    The genesis block is an entirely sui generis block (unique) that is not

    governed by the general rules applying to all other Ethereum blocks.

    Instead, the only consensus requirement is that it must be identical to

    the block added by this function.

    The mainnet genesis configuration was originally created using the

    `mk_genesis_block.py` script. It is long since defunct, but is still

    available at <https://github.com/ethereum/genesis_block_generator>.

    The initial state is populated with balances based on the Ethereum presale

    that happened on the Bitcoin blockchain. Additional ether worth 1.98% of

    the presale was given to the foundation.

    The `state_root` is set to the root of the initial state. The `gas_limit`

    and `difficulty` are set to suitable starting values. In particular the

    low gas limit made sending transactions impossible in the early stages of

    Frontier.

    The `nonce` field is `0x42` referencing Douglas Adams' "HitchHiker's Guide

    to the Galaxy".

    The `extra_data` field contains the hash of block `1028201` on

    the pre-launch Olympus testnet. The creation of block `1028201` on Olympus

    marked the "starting gun" for Ethereum block creation. Including its hash

    in the genesis block ensured a fair launch of the Ethereum mining process.

    The remaining fields are set to appropriate default values.

    On testnets the genesis configuration usually allocates 1 wei to addresses

    `0x00` to `0xFF` to avoid edge cases around precompiles being created or

    cleared (by [EIP-161]).

    [EIP-161]: https://eips.ethereum.org/EIPS/eip-161

    """

    Address: Type[FixedBytes] = hardfork.Address

    assert issubclass(Address, FixedBytes)

    for hex_address, account in genesis.initial_accounts.items():

        address = hardfork.hex_to_address(hex_address)

        hardfork.set_account(

            chain.state,

            address,

            hardfork.Account(

                Uint(int(account.get("nonce", "0"))),

                hex_or_base_10_str_to_u256(account.get("balance", 0)),

                hex_to_bytes(account.get("code", "0x")),

            ),

        )

        for key, value in account.get("storage", {}).items():

            hardfork.set_storage(

                chain.state, address, hex_to_bytes32(key), hex_to_u256(value)

            )

    fields = {

        "parent_hash": Hash32(b"\0" * 32),

        "ommers_hash": rlp.rlp_hash(()),

        "coinbase": Address(b"\0" * Address.LENGTH),

        "state_root": hardfork.state_root(chain.state),

        "transactions_root": hardfork.root(hardfork.Trie(False, None)),

        "receipt_root": hardfork.root(hardfork.Trie(False, None)),

        "bloom": hardfork.Bloom(b"\0" * 256),

        "difficulty": genesis.difficulty,

        "number": Uint(0),

        "gas_limit": genesis.gas_limit,

        "gas_used": Uint(0),

        "timestamp": genesis.timestamp,

        "extra_data": genesis.extra_data,

        "nonce": genesis.nonce,

    }

    if has_field(hardfork.Header, "mix_digest"):

        fields["mix_digest"] = Hash32(b"\0" * 32)

    else:

        fields["prev_randao"] = Hash32(b"\0" * 32)

    if has_field(hardfork.Header, "base_fee_per_gas"):

        fields["base_fee_per_gas"] = Uint(10**9)

    if has_field(hardfork.Header, "withdrawals_root"):

        fields["withdrawals_root"] = hardfork.root(hardfork.Trie(False, None))

    if has_field(hardfork.Header, "blob_gas_used"):

        fields["blob_gas_used"] = U64(0)

    if has_field(hardfork.Header, "excess_blob_gas"):

        fields["excess_blob_gas"] = U64(0)

    if has_field(hardfork.Header, "parent_beacon_block_root"):

        fields["parent_beacon_block_root"] = Hash32(b"\0" * 32)

    genesis_header = hardfork.Header(**fields)

    block_fields = {

        "header": genesis_header,

        "transactions": (),

        "ommers": (),

    }

    if has_field(hardfork.Block, "withdrawals"):

        block_fields["withdrawals"] = ()

    genesis_block = hardfork.Block(**block_fields)

    chain.blocks.append(genesis_block)

    chain.chain_id = genesis.chain_id