Can precompiles be written in Solidity/ Yul?

Question

Based on the answers to this other question, I understand that there isn't a standard programming language in which precompiles are written in.

The standard EVM precompiles are implemented in the programming language in which the client software is written in, e.g. for go-ethereum and revm.

But what about precompiles used in rollups and sidechains? I saw some projects with precompiles written in Yul, e.g. zkSync's bootloader, and other projects using Solidity directly, e.g. Hedera's HederaTokenService.

If precompiles can indeed be written in Solidity/ Yul, how do node clients use these contracts in practice? Is the bytecode hardcoded into the client somewhere?

Or is it that both zkSync and Hedera provide a native implementation (e.g. in Rust) of their precompiles, but provide these Solidity/Yul as syntactic sugar for their users?

Answer 1

Solidity precompiled contracts are similar to regular contracts, with one key difference: they are not deployed but instead created through the genesis JSON file at the launch of a blockchain. As such, their address, bytecode, and storage can be freely configured. For example: Consensys Permissioning Smart Contracts.