What are the known differences between zkevm-rom and EVM

1. 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

2. Precompiled: zkEVM 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 Polygon 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