The `COINBASE` address shall be warm at the start of transaction execution, in accordance with the actual cost of reading that account.
## Motivation
Direct `COINBASE` payments are becoming increasingly popular because they allow conditional payments, which provide benefits such as implicit cancellation of transactions that would revert.
This gas cost mismatch can incentivize alternative payments besides ETH, such as ERC20, but ETH should be the primary means of paying for transactions on Ethereum.
## Specification
At the start of transaction execution, `accessed_addresses` shall be initialized to also include the address returned by `COINBASE` (`0x41`).
## Rationale
The addresses currently initialized warm are the addresses that should already be loaded at the start of transaction validation.
The `ORIGIN` address is always loaded to check its balance against the gas limit and the gas price.
The `tx.to` address is always loaded to begin execution.
The `COINBASE` address should also be always be loaded because they receive the block reward as well as the transaction fees.
## Backwards Compatibility
There are no known backward compatibility issues presented by this change.
## Security Considerations
There are no known security considerations introduced by this change.
## Copyright
Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).