[ZK Stack] - How to upgrade the bootloader system contract?

[moneta]

Team or Project

No response

Module Affected

• System contracts (era-system-contracts)
• Smart contracts (era-contracts)
• zkEVM (era-zk_evm)
• Server (zksync-era)
• Prover (era-boojum)
• Fee withdrawer (era-fee-withdrawer)
• Block Explorer (clock-explorer)
• Portal - Wallet + Bridge (dapp-portal)
• Other (please specify below)

Rust Version

1.85.0

Operating System

• Ubuntu
• MacOS
• Windows
• Other (Please specify below)

Issue Description

We deployed a new zkChain on Sepolia testnet. From the documents we know that the zkEVM run the bootloader contract to execute all L2 transactions in a L1 batch.

We have some modifications to the bootloader contract (file bootloader.yul). But we can't file a document how to upgrade the current bootloader to the new contract.

Is it possible?

Thank you in advance.

Expected Behavior

Got a how-to document to upgrade bootloader system contract

Current Behavior

Cannot find the document for upgrading the bootloader contract.

Repository Link (if applicable)

No response

Additional Details

No response

Prior Research

• Yes, I searched for similar issues and did not find any matching ones.

[sarahschwartz]

Hi @moneta! I believe that to deploy a chain to the Elastic Network, you cannot modify the bootloader code. However if you aren't planning on doing that, I can investigate what steps are required to do this.

[moneta]

@sarahschwartz Looks like it is not that simple. From reading the source code, looks like we would have to send a upgrade event and it then will trigger update a new bootloader code to the table factory_deps in the database.

Please can you help with any document/instruction how to do that? Thank you very much

[sarahschwartz]

@moneta Can you clarify what your plan is with the chain? As I said, I don't believe you are able to deploy the chain to the ZKsync Elastic Network on mainnet if you modify the bootloader contract.

[moneta]

@sarahschwartz My plan is to add one more address to share the transaction fees with the fee_account. In order to do that, I changed the bootloader contract. I have deployed both ecosystem and a zkChain on Sepolia. On the mainnet, we want to deploy both a new ecosystem and new chain.

Please correct me if I was wrong, I understand that the bootloader contract is loaded by zkEVM machine when it executes all transactions in a L1 batch. The bytecode of the bootloader is pulled from the database (table factory_deps).

So in order for zkEVM to pickup new bootloader bytecode, I would have to call the method setNewVersionUpgrade of the ChainTypeManager contract. This action would trigger the event that is caught by the event_watcher component and then the new bootloader contract will be loaded from disk and save to the factory_deps table.

Now, we are stuck with calling the method setNewVersionUpgrade.

[sarahschwartz]

Thanks for clarifying. We don't have full documentation for running a custom ecosystem at this point unfortunately. You may find the spec book helpful though.