EVM Compatibility

EOS EVM is fully compatible with the Ethereum EVM specification, including all precompiles and opcodes. However, there are some key EOS EVM differences:

Nested Call Limit

Due to a limitation in the EOS EVM Contract, EOS EVM currently supports a maximum of five (5) nested calls. The EOS EVM team will keep optimizing designs to increase this number.

Reserved Addresses

EVM addresses that begin with twelve 0xbb bytes, e.g. 0xbbbbbbbbbbbbbbbbbbbbbbbb5530ea015b900000, are reserved for bridging EOS between native EOS and EOS within EVM. Sending messages to these addresses with a value may initiate a bridge transaction or abort the transaction depending on various bridge rules.

Also, while unlikely, any contract creation which results in a reserved address will also abort the transaction.

Precompiles

EOS EVM supports all precompiles supported by Ethereum, with the following provisions:

modexp (0x05)

The exponent bit size cannot exceed either the base bit size or the modulus bit size.

ℹ️ Unmet limits
If the above limits are not met, the precompile will throw an exception and the transaction will be halted.

Opcodes

BLOCKHASH (0x40)

This opcode currently does not return the hash of the specified block contents, but the hash of the specified block height and the chain ID instead:

block_hash = sha256( msg(block_height, chain_id) )

where:

• block_height: specified 64-bit block height
• chain_id: used as a 64-bit salt value
• msg: concatenation of a leading zero byte (0x00) constant, the block_height, and the chain_id, in big endian format.

ℹ️ Version byte
The leading zero byte in the hash is a version byte which may change if a new blockhash scheme is introduced in the future.

COINBASE (0x41)

This opcode returns the address of the EOS EVM contract account, eosio.evm. The current address is 0xbbbbbbbbbbbbbbbbbbbbbbbb5530ea015b900000.

DIFFICULTY (0x44)

This opcode currently returns 1 (one) by default since there is no hash difficulty in the underlying EOS consensus protocol.

GASLIMIT (0x45)

This opcode currently returns 0x7FFFFFFFFFF (2^43-1) as the maximum gas limit in EOS EVM.

PUSH0 opcode

The EOS EVM does not currently support PUSH0, so you need to use solidity version 0.8.19 or below.