The Core Space VM is compatible with the EVM in most cases, but there are some differences. This page lists the differences between the two.
The contract address calculation is different from Ethereum. Check Core Address for more details.
The 1820 registry is a contract that stores the addresses of other contracts that implement certain interfaces. It is used to implement the EIP-1820 standard. The 1820 registry is deployed at Core Space hex40 address
BLOCKHASHopcode can only take
NUMBER-1as input. (Unlike Ethereum, which takes any integer in
NUMBER-1as input). This is the only break opcode.
Which means the Solidity built-in function
blockhash can only take
block.number - 1 as input.
Block Gas Limit
The block gas limit is fixed at 30000000.
block.number is the sequence number in whole tree-graph.
Core Space has some built-in internal contracts that are not in Ethereum.
- Gas used and refund: Conflux requires less gas in
SSTOREoperation but no longer refunds resetting storage and contract destruction.
- Gas Fee Refund: In Ethereum, if a transaction's gas limit exceeds the actual gas cost, the remaining gas is fully refunded. In contrast, Conflux refunds a maximum of 1/4 of the gas limit. Setting an excessively high gas limit in Conflux can lead to additional transaction fee costs. However, no extra fees are incurred if the gas limit is set to less than 4/3 of the actual cost. Therefore, providing an accurate gas estimate for a transaction is crucial for optimizing transaction fees.