Hi,
ArbOS is an important piece of Arbitrum technical stack. However its a complex codebase, with a lot of internals difficult to understand.
To ease the exploration of community member, we (Trail of Bits) released a code walkthrough where we over over ArbOS codebase and details some of its aspect. Our engineers have been working on Arbitrum for the past 4 years, and leverage their insights to detail how does ArbOS message parsing work, how the transaction are processed, how the block are created and how retryable tickets are handled.
We hope that this video will help the community to better understand ArbOS.
disclaimer: Trail of Bits is part of the ARDC proposal