[docs]:Known differences between zkevm-rom and EVM

[invocamanman]

Description

• opcodes
  • SELFDESTRUCT: removed by SENDALL
  • EXTCODEHASH: returns hash contract bytecode from zkEVM state tree (do not check if the account is empty)
  • DIFFICULTY: returns 0
  • BLOCKCHASH: returns all previous block hashes (not just the last 256 blocks)
    • BLOCKCHASH is the state root at the end of a processable transaction and it is stored on the system smart contract
  • NUMBER: number of processable transactions
• precompiled
  • supported
    • ecRecover
    • identity
  • rest of the precompiled do a revert
• other differences
  • Do not clean the storage when a contract is deployed in that address. (not possible due to zkEVM state tree specification)
  • JUMPDEST opcode allowed in push bytes (avoid runtime bytecode analysis)
  • implements eip-3541 which belongs to London hardfork
  • eip-2718 which defines Typed Transaction Envelope are not supported
    • eip-2930 tx type, Optional access lists is not supported
• additions
  • zk-counters: batch resources available linked to state-machines components