Advanced users • Feature Request: PCIe Device Mode & General DMA Access for Raspberry Pi

Hello Raspberry Pi Team,

I’d like to suggest a potential feature for future Raspberry Pi models:

**PCIe Device / Slave Mode with General DMA Access.**

### Use Case
- High-speed data acquisition from external PCs or devices.
- FPGA co-processing where the Pi acts as shared memory.
- Low-latency memory access for AI or robotics applications.

### Current Limitation
- The Pi 5 can act as a PCIe host, reading/writing to attached devices like NVMe SSDs.
- Currently, it **cannot act as a PCIe device/slave**, so another PC cannot perform DMA directly into Pi memory.

### Proposal
- Expose a PCIe device/slave mode in a future Pi board.
- Allow secure, controlled DMA access to RAM from an external PCIe host.
- Optional: Provide software / library support for safe memory mapping.

### Benefits
- Unlocks advanced applications such as real-time data streaming, high-speed peripheral interfacing, and shared memory between PCs and Pi.
- Opens doors for research, industrial projects, and hobbyist experimentation.

### References / Notes
- Some ARM SoCs support PCIe device mode; it’s feasible with proper hardware design.
- Many hobbyist DMA libraries exist internally, but extending this to external PCIe hosts is currently impossible.

I hope this suggestion can be considered for future models. I’d be happy to discuss technical details or potential applications with the team and community.

Thank you for your time and all the amazing work with Raspberry Pi!

Statistics: Posted by notthecloudy — Tue Mar 03, 2026 10:50 pm — Replies 0 — Views 15

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