# UAD-2 OCTO: tracing PCIe command rings and DSP resource loading

> UAD-2 OCTO-RE investigates the PCIe host transport of a Universal Audio DSP card through driver analysis and experiments on one Rev 5 board. The author reports reproducing command-ring and DMA startup across eight DSPs and recovering parts of the firmware and Bill resource containers. General-purpose DSP execution remains blocked by an unresolved runtime response and opaque payload format.

- Type: Case study
- Targets: Binary · Firmware · Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-08
- Original resource: <https://github.com/ahmadexp/UAD2-OCTO-RE>
- Primary source: <https://github.com/ahmadexp/UAD2-OCTO-RE/blob/f4da3ab8ff74ded71af7d7ad35ba7dccbac781ed/README.md>
- Catalog page: <https://awesomerea.org/resources/uad2-octo-pcie-case/>
- Record JSON: <https://awesomerea.org/resources/uad2-octo-pcie-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/uad2-octo-pcie-case/index.md)

## Requirements & limits

- **Prerequisites:** Experiments target a UAD-2 OCTO Rev 5 card with an isolated IOMMU group and the documented PCIe profile.
- **Prerequisites:** The hardware procedures involve low-level PCIe, MMIO, DMA, interrupt and reset access.
- **Limits:** General-purpose DSP execution has not been achieved.
- **License:** GPL-2.0-only licence.

## Primary sources

1. <https://github.com/ahmadexp/UAD2-OCTO-RE/blob/f4da3ab8ff74ded71af7d7ad35ba7dccbac781ed/README.md>
2. <https://github.com/ahmadexp/UAD2-OCTO-RE/blob/f4da3ab8ff74ded71af7d7ad35ba7dccbac781ed/docs/architecture.md>
3. <https://github.com/ahmadexp/UAD2-OCTO-RE/blob/f4da3ab8ff74ded71af7d7ad35ba7dccbac781ed/docs/bill-resource-analysis.md>

## More in Firmware and hardware

- [GameSir Cyclone 2: firmware findings and controller bridge](https://awesomerea.org/resources/gamesir-cyclone2-case/index.md) · Case study
- [airport-express-tools: rebuilding AirPort Express configuration and Wi-Fi client mode](https://awesomerea.org/resources/airport-express-tools-case/index.md) · Case study
- [Gaomon M10K 2018: firmware decoding and report-rate investigation](https://awesomerea.org/resources/gaomon-m10k-2018-firmware-case/index.md) · Case study
- [nokia105-emu: Nokia 105 firmware emulation](https://awesomerea.org/resources/nokia105-firmware-emulation-case/index.md) · Case study
- [Hisense VIDAA (MT9603): firmware and local bridge findings](https://awesomerea.org/resources/hisense-vidaa-mt9603-case/index.md) · Case study
- [WebTV PTL: documenting the set-top box listings format](https://awesomerea.org/resources/webtv-ptl-format-case/index.md) · Case study

## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.