Discrepancy in L2ToL1MessagePasser Proof with Deposits in Optimism

[smallyunet]

I've been diving deep into the Optimism protocol, specifically focusing on the deposit and withdrawal flows. I've observed a phenomenon that I'm trying to understand better:

When funds are deposited from L1 to L2, it seems that the L2ToL1MessagePasser contract's state (and consequently its proof) is altered. However, based on the documentation and code I've reviewed, I'm struggling to pinpoint the exact line of code or mechanism that processes this cross-chain deposit message on L2 and leads to the change in the L2ToL1MessagePasser contract's state.

Moreover, I've noticed that if funds are allocated in the genesis.json of the L2 node, they don't seem to be reflected in the L2ToL1MessagePasser proof. This raises questions about the consistency and security of the cross-chain communication.

Could someone shed light on:

1. The specific line of code or mechanism in Optimism that processes the L1 to L2 deposit message and alters the L2ToL1MessagePasser contract's state?
2. Why funds allocated directly in the genesis.json of L2 aren't reflected in the L2ToL1MessagePasser proof?

Any insights or clarifications would be greatly appreciated.