Hacker Neue

Preferences
spuz parent
This looks like an incredible achievement. I'd love to see some photos of the physical device. I'm also slightly confused about which FGPA module is being used. The blog mentions the Xylinx Kria SoMs but if you follow the links to the specs of those modules, you see they have ARM SoCs rather than Xylinx FGPAs. The whole world of FGPAs is pretty unfamiliar to me so maybe I'm missing something.

https://www.amd.com/en/products/system-on-modules/kria/k26/k...

PfhorSlayer
You're in luck! https://imgur.com/a/BE0h9cZ

As mentioned in the rest of this thread, the Kria SoMs are FPGA fabric with hardened ARM cores running the show. Beyond just being what was available (for oh so cheap, the Kria devboards are like $350!), these devices also include things like hardened DisplayPort IP attached to the ARM cores allowing me to offload things like video output and audio to the firmware. A previous version of this project was running on a Zynq 7020, for which I needed to write my own HDMI stuff that, while not super complicated, takes up a fair amount of logic and also gets way more complex if it needs to be configurable.

crote
> you see they have ARM SoCs rather than Xylinx FGPAs

It's a mixed chip: FPGA and traditional SoC glued together. This mean you don't have a softcore MCU taking up precious FPGA resources just to do some basic management tasks.

spuz OP
Ah that makes sense. It's slightly ironic then that the ARM SoC includes a Mali GPU which presumably easily outperforms what can be achieved with the FGPA.
chrsw
I didn't see any mention of what the software on the Zynq's ARM core is doing, which made me wonder why use Zynq at all.
PfhorSlayer
The hardened DisplayPort IP is connected to the ARM cores, and requires a significant amount of configuration and setup. FuryGpu's firmware primarily handles interfacing with that block: setting up descriptor sets to DMA video frame and audio data from memory (where the GPU has written it for video, or where the host has DMA'd it for audio), responding to requests to reconfigure things for different resolutions, etc. There's also a small command processor there that lets me do various things that building out hardware for doesn't make sense - moving memory around with the hardened DMA peripheral, setting up memory buffers used internally by the GPU, etc. If I ever need to expose a VGA interface in order to have motherboards treat this as a primary graphics output device during boot, I'd also be handling all of that in the firmware.
chiral-anomaly
Xilinx doesn't mention the exact FPGA p/n used in the Kria SoMs. However according to their public specs they appear to match [1] the ZU3EG-UBVA530-2L and ZU5EV-SFVC784-2L devices, with the latter being the only one featuring PCIe support.

Designing and bringing-up the FPGA board as described in the blog post is already a high bar to clear. I hope the author will at some point publish schematics and sources.

[1] https://docs.amd.com/v/u/en-US/zynq-ultrascale-plus-product-...

This item has no comments currently.