# Bringing up Cosmo

- Show: [Oxide and Friends](https://hardwarepodcasts.com/podcast/oxide-and-friends)
- Published: 2025-04-24
- Length: 1h 55m
- Episode: 14
- Page: https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo
- Listen: https://share.transistor.fm/s/09178df0

## Summary

Nathanael Huffman, Matt Keeter, Ian Sobering, and Aaron Hartwig of Oxide Computer Company detail the bring-up of their next-generation Cosmo server sled, contrasting it with the painful Gimlet launch. The team leveraged a custom test board called Grapefruit to risk-retire FPGA logic and firmware before tape-out, enabling a remarkably smooth initial power-on. However, they encountered critical debugging challenges, including a blown FPGA pin due to a bus contention error and a subtle FPGA toolchain bug involving an undriven reset pin that prevented the AMD Turin CPU from exiting reset.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=0) Introduction: Cosmo Bring-up Overview and Gimlet Lessons
- [5:01](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=301) Design Process: Moving from Cadence to Altium and Owning the Library
- [10:48](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=648) Architecture: Using FPGAs for Sequencing, Hot Plug, and eSPI Boot
- [24:41](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=1481) Grapefruit: The OCP DC-SCM Test Board for Risk Retirement
- [40:22](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=2422) Initial Bring-up: Powering On, Reworks, and Blown Components
- [56:39](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=3399) Debugging: Crystal Oscillators, Sequencing Handshakes, and eSPI Wiggles
- [1:26:27](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=5187) The Root Cause: Undriven Reset Pin and Vivado Toolchain Behavior
- [1:37:09](https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo#t=5829) Final Fixes: SPD Level Translators, Hot Plug, and Full System Boot

## Topics

- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Embedded firmware](https://hardwarepodcasts.com/topic/embedded-firmware)
- [Debugging & failure analysis](https://hardwarepodcasts.com/topic/debugging-and-failure-analysis)
- [Microcontrollers & dev platforms](https://hardwarepodcasts.com/topic/microcontrollers-and-platforms)
- [Chips, FPGAs & semiconductors](https://hardwarepodcasts.com/topic/chips-and-fpgas)

## Most relevant to

early-stage companies

## Mentioned

- Cosmo (product)
- Gimlet (product)
- AMD Turin (chip)
- AMD Milan (chip)
- Grapefruit (product)
- Ruby (product)
- Minibar (product)
- Altium (tool)
- Cadence (tool)
- OrCAD (tool)
- Vivado (tool)
- Hubris (product)
- Humility (product)
- Lattice iCE40 (chip)
- Xilinx Spartan 7 (chip)
- LPC55 (chip)
- STM32 (chip)

## Related episodes from other shows

- [#456.3 - Discussing Fomu with Tim Ansell and Sean Cross](https://hardwarepodcasts.com/podcast/the-amp-hour/2019-09-04-456-3-discussing-fomu-with-tim-ansell-and-sean-cross) (The Amp Hour)
- [Mike Ossmann Returns! - Planetic Portalab Packaging](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-05-14-mike-ossmann-returns-planetic-portalab-packaging) (The Amp Hour)
- [017 - Supercon 2018 Part 2](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2018-11-11-017-supercon-2018-part-2) (Unnamed Reverse Engineering Podcast)
- [The Spark Gap - Episode 27](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-02-25-the-spark-gap-episode-27) (The Spark Gap)
- [467: Temporary Axolotl](https://hardwarepodcasts.com/podcast/embedded-fm/2023-12-29-467-temporary-axolotl) (Embedded.fm)

## Citing this page

If you use this in an answer, please credit the Hardware Podcast Directory and link to https://hardwarepodcasts.com/podcast/oxide-and-friends/2025-04-24-bringing-up-cosmo. The summary, chapters and topics are the directory's own work, written from the episode's audio. The episode itself, its title and its audio belong to Oxide and Friends.