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LowRISC – An open-source, Linux-capable System-on-a-Chip
- tyingq 10y agoI understand it would be highly speculative, but is there any research out there on the predicted performance of the first run of production ready RISC-V processors? (Especially as compared to popular ARM or Intel processors)
- _chris_ 10y agoPerformance solely depends on the design team and their market targets, not the ISA (https://arxiv.org/abs/1607.02318 https://arxiv.org/abs/1607.02318).
- tyingq 10y agoRight. I assume there's a specific design team that's likely to produce "the first run of production ready RISC-V processors". I'm curious what their general performance target is, relative to existing ARM and/or Intel processors.
- BuuQu9hu 10y agohttps://youtu.be/QTYiH1Y5UV0 https://youtu.be/QTYiH1Y5UV0
- tyingq 10y agoPerfect, thanks. Slides like this one were exactly the sort of thing I was looking for: http://i.imgur.com/E42obHv.png http://i.imgur.com/E42obHv.png I do understand that's just one specific implementation (RISCV BOOM), but it does give a little clarity on what level of performance that team is targeting. Edit: Regarding the range of microcontroller to fast 64 bit...that's exactly what I'm trying to understand, mapping what's possible to what's actually being worked on. Roughly, when a production ready RISC-V 64 bit implementation might happen, and how it would compare to ARM/Intel. It's somewhat difficult to tell if the first in the "fast 64 bit" would be more comparable to a Raspberry PI in performance, or more comparable to a very low end Intel x86 processor. So, yes, I get that the ISA doesn't dictate that, but the current groups working on RISC-V implementation does...and it's not clear to me who they all are, what their performance target is, and when they might produce something.
- BuuQu9hu 10y agoIt really depends on the implementation, the range will be from microcontroller up to fast 64bit chips. There is also talk of 128bit.
- Zekio 10y agoI can't wait for these System on a Chips to be used on a Single Board Computer, which is priced around the same as a Raspberry Pi
- BuuQu9hu 10y agoRISC-V isn't quite to that stage yet, but: https://www.crowdsupply.com/onchip/open-v https://www.crowdsupply.com/onchip/open-v https://www.crowdsupply.com/sifive/hifive1 https://www.crowdsupply.com/sifive/hifive1
- duskwuff 10y agoNote that the HiFive is a microcontroller-class RISC-V implementation. (Low pin count, 16 KB SRAM, no external memory interface.) This isn't meant to insult it; it's just in a different space from the LowRISC project.
- asb 10y agoWe are working towards producing a lowRISC SoC design along with low-cost development boards. I will say that hitting the Raspberry Pi pricepoint is challenging. It's a hard price to hit even when using off-the-shelf silicon that's already produced in huge volume. Our lower volume will mean our cost-per-chip is somewhat higher. Ultimately, our hope is that the lowRISC SoC can act something like the "Linux of the hardware world" - that others can take it as a base for their own SoC designs (startups, academics, larger companies). The most likely route to an ultra low cost design is likely one of the large semiconductor vendors producing and selling a derivative design.
- cryptarch 10y agoI'll take a fully open-source computing device with Core2Duo-like performance any day, especially if the CPU is open source too. I'm just hoping it won't have any firmware blobs. Would this being built on RISC-V help with getting a formal CPU spec?
- BuuQu9hu 10y agoRISC-V is no guarantee that the CPU is open source. RISC-V is only an open source ISA. Implementations of it could be proprietary or open source. Some could have firmware blobs. Some of the RISC-V ISA details are final and some are not. Check their website for the specs.
- deleted 10y ago[deleted]
- asb 10y agoRISC-V is an open specification that can be implemented by proprietary and open source efforts alike. This means there's nothing stopping someone else doing a RISC-V SoC that, like most current commercial cores, has documentation "protected" by an NDA and inaccessible to most users. As a fully open source effort, we of course want every aspect of the chip to be fully documented and auditable. It's useful to have something like a dedicated core to handle initial boot, but it's not useful to keep that core completely undocumented (e.g. the Intel Management Engine). Our answer there is what we term 'minion cores' (http://www.lowrisc.org/downloads/lowRISC-memo-2014-001.pdf http://www.lowrisc.org/downloads/lowRISC-memo-2014-001.pdf), microcontroller-class cores to handle these sort of tasks. These are fully documented, open source, and implement the RISC-V ISA. As for formal specifications, there has been some work on specifying the RISC-V ISA using L3 https://github.com/SRI-CSL/l3riscv https://github.com/SRI-CSL/l3riscv. MIT have been working on a specifying using their 'Kami' tool as well.
- cryptarch 10y agoSure, I just meant that RISC-V being permissively licensed with in-depth documentation available will ease formally verifying implementations of it, and also encourage open-source implementations. On the minion cores: that sounds quite interesting and I'm reading the paper now. Are they very different from e.g. the USB and network chips on the RPi, aside from having open firmware?
- Lio 10y agoIt would be interesting to get RMS' thoughts on this project. Finally the prospect of fully Free mainstream computers looks like it's becoming a reality.
- BuuQu9hu 10y agohttps://www.gnu.org/philosophy/free-hardware-designs.html https://www.gnu.org/philosophy/free-hardware-designs.html It will be a while before RISC-V is supported by Free Software distributions and a while before hardware will be available to buy.
- groks 10y agoDone! https://rwmj.wordpress.com/2016/10/15/fedorarisc-v-is-finished/ https://rwmj.wordpress.com/2016/10/15/fedorarisc-v-is-finish...
- asb 10y agoI hope we'll be 'Respect Your Freedom' compliant https://www.fsf.org/resources/hw/endorsement/respects-your-freedom https://www.fsf.org/resources/hw/endorsement/respects-your-f.... This is of course trivial for our core SoC, where we have no intention of relying on binary blobs. It just may affect our selection of external parts, e.g. WiFi chips. I often relate the way we're going about this to the early days of the GNU project. Our ultimate aim is an SoC where all of the RTL for every component is open source, though it may be that just like GNU which iteratively replaced proprietary components of Unix we may need to have some intermediate stepping stones. e.g. an SoC with a proprietary USB controller, until an appropriate open replacement can be written and verified.
- BuuQu9hu 10y agoAn interesting talk from the RISC-V folks: https://youtu.be/QTYiH1Y5UV0 https://youtu.be/QTYiH1Y5UV0
- asb 10y agoI'm one of the founders of lowRISC, a not-for-profit effort to produce a completely open source, Linux capable, multi-core SoC. Fundamentally, we believe that the benefits of open source we enjoy in the software world can be applied to the hardware world will have a huge positive effect on the hardware industry, academia, and wider society. Much like with Raspberry Pi, our approach is to lead by _doing_ which is why we're working to create our own SoC platform and low-cost development boards. I should point out the title has been editorialised slightly inaccurately. Rob Mullins is a fellow co-founder of lowRISC and was also a Raspberry Pi founder, and I took a leading role in Raspberry Pi software work for a number of years, but it's not really accurate to say lowRISC is backed by "the makers of Raspberry Pi". If you have any questions, I'll do my best to answer (I'm on a short holiday right now, so have slightly intermittent internet access).
- comboy 10y agoDo you plan to release any official dev board(s)?
- asb 10y agoAbsolutely. Our main focus right now is in completing the RTL design for our initial SoC platform, at which point we can perform a test run (multi-project wafer) and ultimately volume production.
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- airbear 10y agoI'm in the aerospace industry and I know my company and others would be very much interested in this. As I'm sure you're aware aerospace requirements are primarily on the environmental envolope of the chip (temperature, vibration, mechanical shock, EMI, etc) - to that end, I know it's tangential to consumer electronics, but is it in the cards to do any sort of radiation testing on the first run? Similarly, do you have a notion yet what sort of EMC standards you'll want to comply to? (if any). I'd love to help with this!
- optforfon 10y agoI'm not really fully involved in the ecosystem too much, but has open source hardware really paid off? Like I see that you can get cheap knockoff Arduinos - but that's not really moving things forward. Are people forking board designs and selling their own twists? (honest question..)
- nickez 10y agoIt works pretty good for CERN. http://www.ohwr.org/ http://www.ohwr.org/
- asb 10y agoI think that's a really good question. How many people make derivative designs from the Arduino is hard to say. It seems more common to prototype with an Arduino, and then when moving to a product to do a custom board design (as lets face it, integrating an AVR or M0 microcontroller isn't particularly challenging). I think the community of people producing 3d printer motor control PCBs etc is a great example of a successful open hardware effort. I believe open source silicon design has much more to offer than just lowering unit costs and increasing profit margins for the existing dominant players. This is why we are established as an independent not-for-profit - we want open source hardware to benefit everyone, and its design to be a truly collaborative process. We have a long way to go, but that's the direction we want to help move things in. We are set up as a UK Community Interest Company, which that means we define a particular community we hope to benefit. For us that is anybody who may either adopt or benefit from open source hardware - whether they're a hobbyist, academic, small startup, established company, and whether they're currently sponsoring our efforts or not.
- juliendorra 10y agoIn the Arduino case, open design of the board is a major factor in the ecosystem success: Arduino itself is a derivative from the Wiring board. Board like the lilypad were invented and derived and opened new avenues to Arduino-based projects (wearable in the case of the Lilypad). There are many specialized arduino-derived boards, and of course the shield ecosystem. Having a common, simple IDE is also a big part of the success, and was helped by open design and specs. For better or worse Arduino and friends are the go-to boards for prototyping, from humble beginnings as artist workshop helpers in northern Italy more than a decade ago. For a more recent interesting example, Josef Prusa built and gave away its design for its 3D printers, they were cloned by dozens and sold everywhere in the world. When he launched his company, he had instant recognition and thousands of customers ready to buy. (The reprap community is a fascinating example of real open innovation, advancing very differently than labs or startups or big companies would)
- cmrdporcupine 10y agoI'm eagerly awaiting this project, I can't wait to get my little consumer hands on a RISC-V board to play with. They're doing great work, but is it a bit delayed? I read about this project some time ago and thought they were further along.
- asb 10y agoYes, we're behind where we initially thought we could be. When we first started, we hoped we might produce a test chip in 2016. This hasn't happened. One major factor is it's been difficult to grow our team. Finding people with the right experience is really hard, and finding people with the freedom and desire to trade-off lower pay for greater flexibility working in a University environment makes it more difficult.
- cyphar 10y agoCan anyone find a link to the actual HDL files? I couldn't find a single link on the website to where the source code for the SoC is (and they are very vague about what license the HDL is under).
- asb 10y agoEverything is up at https://github.com/lowrisc https://github.com/lowrisc. We recently had a website redesign which is 'soft launched' (in that there are a number of regressions like this I need to sort out). Amongst other pieces of IP, we build upon the Rocket implementation from UC Berkeley, which has a BSD license, as well as the PULPino implementation from ETH Zurich (which has an Apache-style license).
- cyphar 10y agoCan you please add a link to that from your website?
- asb 10y agoI've added a link on the 'about' page, in addition to the link that was already there on 'community'. A future restructuring will make it more prominent in the top-level navigation.
- kinghajj 10y agoSo is BOOM officially not going to be the core for the first run, then? If so, are there plans for later generations to switch to it?
- asb 10y agoAssuming sufficient die area on a 28nm test chip, we would like to have a heterogeneous cluster with something like 2xBOOM and 2xRocket.
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- saycheese 10y agoWhat, if any, hardware or code will not be open source on the build you plan to offer that is required to run it?
- _vkcd 10y ago1) How does your feature set compare to SiFive's? 2) Where will your funding come from? Corporate or academic? Will it be enough to scale compared to SiFive?
- asb 10y agoSiFive haven't completed development of their Linux-capable platform (and we haven't completed ours). We both make use of the Rocket codebase. Key differences include our support for tagged memory and minion cores. Funding so far has been via private donation and a grant from Google. I expect we will be funded by a mix of corporate and academic funding going forwards. I believe we are in a position to secure enough funding to produce our open source SoC and low-cost development board. Our goals are completely different to SiFive so it doesn't really make sense to compare 'ability to scale'. Our targets are much more modest - we don't need to generate huge returns for a VC. The investment that SiFive and others are making into the RISC-V ecosystem is fantastic. The great thing about open source is obviously that we all make and benefit from a shared investment.