Running Mujina on amlogic S19 J Pro

[Nickamoto]

I've been contributing through PR reviews (#33, #39) using a Bitaxe Gamma, but recently got my workshop semi-operational and have started experimenting with a S19 J Pro. Wanted to start a discussion about running Mujina natively on this hardware before writing any code.

The S19 J Pro runs an amlogic ARM Linux control board that communicates with three BM1362 hash boards over internal UART, which is the same interface BMMiner and LuxOS use today. BM1362 is already in Mujina's BM13xx protocol module, and the control board exposes SSH and runs a standard Linux environment, so Mujina should be cross-compilable for it. The goal would be deploying Mujina on the control board and having it drive the hash boards directly, replacing the proprietary firmware with an open-source version.

A few reasons I think this is worth pursuing. Purpose-built open hardware that works with Mujina today exists in very limited quantities and isn't widely accessible. S19 J Pros are cheap and easy to find secondhand, so supporting this hardware would open up testing and contribution to a much larger group of people who already own these machines. From a robustness standpoint, an EmberOne runs 12 BM1362 chips and the S19 J Pro runs 378 across three boards at around 100 TH/s. That's a meaningfully different operating environment in terms of concurrent ASIC communication, thermal complexity, and share frequency, and running Mujina at that scale will surface things that help make the software stronger for anyone building on it. And for people who already own S19s and want to run open-source firmware, this gives them a path to do that without replacing their hardware. I see it as a complement to the Libre Board direction rather than a divergence from it. That project is building toward open hardware for hash boards like EmberOne, and this would be the software-only path for existing Bitmain hardware in the meantime.

Before I start digging in, has anyone mapped the UART layout on the S19 J Pro control board or looked at how the control board talks to the hash boards internally? I want to know whether that's documented somewhere or if it needs to be reverse engineered from BMMiner/LuxOS. Also happy to hear if this direction doesn't fit where the project is heading before I go too far down this road.

[skot]

Stoked to see this post! I have been working on this exact thing the last couple weeks. In short I've got Mujina mining on a single hashboard stock S19jPro with Amlogic controlboard and APW121215 PSU. I have support for all 3 hashboards in, but haven't tested it yet due to the power situation in my office.

Here is my prolly-unmergeable fork of Mujina with Amlogic controlboard support; https://github.com/skot/mujina/tree/amlogic-s19jpro

For testing I have been installing LuxOS on the controlboard first because it sets up a writeable filesystem with SSH root user access which stock fw doesn't have. I delete luxminer and all the associated lux-specific setup and then copy over the mujina app, cross-compiled for arm linux.

I'm now working on creating a fresh linux system image that's compatible with the amlogic controlboard and can be flashed to a controlboard running stock firmware (pre- April 2024). Once that's working Mujina can be added to that image.

Here is a repo of the tools and scripts I made to reverse engineer the controlboard pinouts and PSU protocol; https://github.com/skot/amlogic-cb-tools I even got USB dongle wifi working!

[Nickamoto]

This is exactly the kind of overlap I was hoping to find, great timing on both of us looking at this hardware. The amlogic-cb-tools repo is a goldmine, the pinout documentation alone saved a ton of work.

I've got the same setup going: S19 J Pro with LuxOS already flashed and confirmed working via the CGMiner API. Reading through your Mujina fork now and getting familiar with the bring-up path before I start testing.

One thing I want to make sure I understand before I disable LuxOS and deploy. I noticed the hash thread v2 ramps to 500MHz by default. My PSU has been modified for 120V operation while I wait on electrical work for a 240V circuit, so I need to stay around 1kW for now. At 125MHz with LuxOS the machine was drawing around 794W which is comfortable for this setup (I could push it a little higher if needed), but 500MHz is going to cause problems. Is there currently a config knob to set a target frequency, or is that something that would need to be added before this is safe to run on constrained hardware?

[skot]

One thing I want to make sure I understand before I disable LuxOS and deploy. I noticed the hash thread v2 ramps to 500MHz by default. My PSU has been modified for 120V operation while I wait on electrical work for a 240V circuit, so I need to stay around 1kW for now. At 125MHz with LuxOS the machine was drawing around 794W which is comfortable for this setup (I could push it a little higher if needed), but 500MHz is going to cause problems. Is there currently a config knob to set a target frequency, or is that something that would need to be added before this is safe to run on constrained hardware?

I'm also using a Piviotal Pleb 120V unlock modified APW12 PSU. I have been testing with just a single hashboard at 500MHz hash frequency and 12.0V PSU output. That puts me right around 1kW, which so far has been okay with the 120V modified PSU. My mujina fork does not have a hash frequency knob yet... but I'm sure that's part of the plan when BM1362 support gets in mainline.

[Nickamoto]

I'm just now listening to the episode of POD256 where you talk about this, maybe I should have listened before posting this discussion : )

A single hashboard makes sense. I'll work in that configuration for now until I have a dedicated circuit for mining

[rkuester]

There is no external knob at the moment, but you might be able to run at a lower frequency by adjusting this line:

https://github.com/skot/mujina/blob/aeea66ce503a0fc491857eb926ea788d7c809e2a/mujina-miner/src/asic/bm13xx/thread_v2.rs#L655

Be careful, please. No warranties that your S19 won't burst into flames.

[Nickamoto]

Fire extinguisher standing by!

[rkuester]

Stoked to see this thread! We are definitely on the same page about the goal of and reasons to support the S19 and other commercial miners. I also have two S19 J Pros on my lab bench, so it's convenient that we're all converging on the same, first model.

As for the mujina-miner daemon itself, I'm furiously working on merging the emberOne/00 support, which is the basis for Skot's S19 branches and includes that thread v2 component. Then I/we'll start merging in S19 J Pro support into main on top of that.

[Nickamoto]

I have an Avalon 1246 to play with as well. Once we are happy with S19 support, I can use that machine to test on Canaan hardware. Can probably get my hands on some old whatsminers as well.