callした時の情報がstackの上に来る感じでそこからコピーからのdelegate callで実行している

contract Test1Facet {
    event TestEvent(address something);
    function test1Func1() external {}
}

fallback() external payable {
        LibDiamond.DiamondStorage storage ds;
        bytes32 position = LibDiamond.DIAMOND_STORAGE_POSITION;
        // get diamond storage
        assembly {
            ds.slot := position
        }
        // get facet from function selector
        address facet = ds.facetAddressAndSelectorPosition[msg.sig].facetAddress;
        require(facet != address(0), "Diamond: Function does not exist");
        // Execute external function from facet using delegatecall and return any value.
        assembly {
            // copy function selector and any arguments
            calldatacopy(0, 0, calldatasize())
            // execute function call using the facet
            let result := delegatecall(gas(), facet, 0, calldatasize(), 0, 0)
            // get any return value
            returndatacopy(0, 0, returndatasize())
            // return any return value or error back to the caller
            switch result
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }

1. gas: amount of gas to send to the sub context to execute. The gas that is not used by the sub context is returned to this one.
2. address: the account which code to execute.
3. argsOffset: byte offset in the memory in bytes, the calldata of the sub context.
4. argsSize: byte size to copy (size of the calldata).
5. retOffset: byte offset in the memory in bytes, where to store the return data of the sub context.
6. retSize: byte size to copy (size of the return data).