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The new @ethereum system smart contracts to be introduced in Pectra are insanely good for understanding how the low-level EVM works!

Loaded with comments and pseudocode in the EIPs, you can see how the stack and opcodes function very clearly.

🧵👇

Ethereum is the world computer. The universal platform for cryptocurrencies, blockchain apps, stablecoins, and decentralized technologies.

As an example, you can see the Withdrawal code here:
https://github.com/lightclient/sys-asm/blob/main/src/withdrawals/main.eas

It implements EIP-7002, which gives validators the ability to request a withdrawal on the consensus layer directly from the execution layer.
https://eips.ethereum.org/EIPS/eip-7002

The contract is written in geas, an assembler language for EVM with just a couple of features to make development easier, such as labels for variables or jump destinations.
https://github.com/fjl/geas

In the EIP, you can see that pseudocode is provided for a more high-level understanding. Compare it to the opcodes and you'll quickly grasp the assembly code.

It's /ʲustɑs/  •  security research  •  privacy  •  rollups  •  zk-proofs  •  game theory  •  https://ustas.eth.limo/

Near the assembly, you can find helpful comments that indicate what the stack memory currently holds. Observe the changes after each opcode.

For example, the following code will push a constant onto the stack, then push and load the storage slot for the excess value. The constant is first shifted deeper into the stack by the slot, then `SLOAD` "consumes" the slot and replaces it with the value it contains.

See https://www.evm.codes/ to get a reference with an example on each opcode.

Good luck 🍀