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Sipeed Longan Nano – RISC-V Development Board
- ivl 7y agoThis was an instant click but it seems the site is being hugged down.
- deleted 7y ago[deleted]
- non-entity 7y agoPardon my ignorance, but besides being an open-source ISA what's the reason for the popularity for RISC-V? The buzz alone has piqued my interest, but I'm just trying to understand the "why".
- tyingq 7y agoNo ARM-like revenue based royalties, and broadly supported, including mainline Linux kernel support. So, companies like Western Digital are all in. And, if someone makes an "open source" CPU with it, to match the open source ISA, it's a win for trusted computing. Also popular here because some folks imagine a new ecosystem of cheap Rpi type boards with no magical binary blobs. See, for example, lowrisc.org (though they seem far from shipping)
- makomk 7y agoThere's already a lot of Allwinner-based Pi clones with no magical binary blobs, though - depending on the board the only blob may be the non-modifiable boot ROM, which is actually quite convenient for low-level hackers since it just loads your own bootloader from one of several devices and gets out of its way. This includes support for raw NAND flash so in theory you can avoid even having a binary blob in your storage device if you get one of the few boards with raw NAND onboard.
- panpanna 7y agoArm license cost is nothing compared to what they have invested in testing and QA. One round of asic that fails is significantly more expensive. If you are jumping on risc-v to save money you have your priorities very wrong. On the other hand if you are Huawei and can't do business with arm...
- tyingq 7y ago1.5% of your per unit revenue for a hard drive seems significant. WD seems to agree, and they don't seem like a risk prone company.
- panpanna 7y ago1.5% does sound significant, but does WD save 100% of those 1.5% by doing it in-house? Furthermore, those 1.5% covered more than just the CPU (peripherals, buss technologies, patents, manufacturing know-how). I'm not saying WD is wrong, but I think they are overestimating how much they can save. This is probably just to get a better deal from arm.
- phkahler 7y agoFrom their public statements, this is not to get a better deal from ARM. they are all-in with risc-v and have already made public their first core (among other things), which is better than an equivalent from ARM. At this point I dont think ARM could bring much to the table for WD. They've invested way beyond what makes sense for getting better pricing.
- hajile 7y ago1.5% of a big number is still a big number. Western Digital's revenue in 2018 was 18 billion. Even if only 0.15% of their revenue went to ARM, that would be 27M or enough to hire 100 chip designers at 270K each. That would be enough people for a very advanced chip, but WD doesn't need to build the next supercomputer. Instead, they want a chip customized to handle their specific workload with high throughput and probably some specialized instructions to put some algorithms in hardware. Moreover, their RISCV chip design expense should reduce over time both because they don't need to change chip micro-architectures very often and because as more companies switch to shared, open hardware, the costs are reduced Another example is Nvidia. They continue to hold an ARM license for several ARM designs and another license for their own custom Denver/Carmel designs. Despite this, they still opted to use RISCV in their GPUs. These companies manufacture chip designs for a living. They certainly understand the costs involved and have determined the immediate and long-term costs are lower vs the provided benefits.
- slezyr 7y ago> Also popular here because some folks imagine a new ecosystem of cheap Rpi type boards with no magical binary blobs. See, for example, lowrisc.org (though they seem far from shipping) I thought that the biggest blob in most linux systems is GPU driver and RISC-V doesn't solves this.
- tyingq 7y agoThere's a mystery boot blob in the RPi that's pretty famous.
- wolfgke 7y agoThis is because of the specific architecture of BCM2836, BCM2837, and BCM2711B0, which are rather VideoCore chips with appended ARM cores.
- imtringued 7y agoI'm not sure what you are talking about. There is no such thing as a mystery boot blob in the Raspberry Pi. It is well known that the video core chip is the main processor of the Raspberry Pi. It runs a proprietary RTOS called ThreadX. As an afterthought someone added a bunch of ARM cores to the Video Core chip which obviously has to cooperate with the main processor to do anything at all. https://www.heise.de/select/ct/2016/8/1460193213013079/contentimages/Raspi_Broadcom_mtk_IG.jpg https://www.heise.de/select/ct/2016/8/1460193213013079/conte...
- tyingq 7y agoSo you're saying there's source available for the boot binary?
- wolfgke 7y ago> I thought that the biggest blob in most linux systems is GPU driver and RISC-V doesn't solves this. It makes no sense to counter a hypetrain with intelligent arguments. :-) Of course, you are right.
- 7y ago
- panpanna 7y agoIt's the new thing. I don't think it is significantly better than existing ones (including the now fully open source mips). And it is already significantly fragmented. But it's the new thing and where the mindshare currently is. Many new ideas are tested on risc-v, and there exist multiple open source implementations.
- mrob 7y agoCombination of simplicity (at least before you start adding extensions), and good software support. It's easy to understand like the old 8-bit ISAs, but you can still use modern compilers.
- non-entity 7y ago> It's easy to understand like the old 8-bit ISAs Oh that's kinda cool. Playing with 8-bit processors is what first got me interested in low level computing and helped a lot of things "click" for me
- als0 7y agoWhat particularly bugs me are the false claims that say using RISC-V will make you more secure.
- eeZah7Ux 7y agoThe weapon manufacturers investing in the RISC-V foundation might disagree.
- als0 7y agoRISC-V changes the economics of processor development. It doesn't improve security for end users.
- tasty_freeze 7y agoI assume what people are referring to when they say that is the embedded security processors in Intel and AMD chips.
- dreamcompiler 7y agoThe lack of speculative execution or a Management Engine strongly suggests these claims are true.
- floatboth 7y agoThese things have NOTHING to do with the ISA.
- skunkpocalypse 7y agoThen why can't I buy an amd64-ISA chip without one? It has quite a lot to do with the ISA's licensor.
- dreamcompiler 7y agoCorrect but all current implementations don't have them, and Patterson has recommended against SE as being be more trouble than it's worth.
- chongli 7y agoIt's been quite a while (several years) since I read the original paper [1] on RISC-V's design but I remember it being very elegant, with a lot of things fixed that other ISAs have been stuck with for decades. It's truly modern in the sense that it demonstrates how much we've learned in the last few decades, without being such a radical departure that it requires rearchitecting all software for it. [1] https://people.eecs.berkeley.edu/~krste/papers/EECS-2016-1.pdf https://people.eecs.berkeley.edu/~krste/papers/EECS-2016-1.p...
- kbumsik 7y agoNote that most of RISC-V chips arise in China. As seen in the fight between Trump and Huawei (ARM almost ended contract with Huawei) I think RISC-V becoming a great possible alternative to ARM for Chinese companies.
- childintime 7y agoFor me it is clear RISC-V will become the defacto standard in processors, soon it'll even compete on the high end. So besides being cheaper: - as a developer my RISC-V (assembly and system) skills will remain relevant and valuable - by using RISC-V MCU's now I will avoid future family migrations - RISC-V's are already the MCU's of choice embedded in FPGA's and AI chips, and I won't need to learn another tool before being able to utilize them - RISC-V enables collective community-enabled innovation (which was the prime driver for creating it) - Rust runs on RISC-V MCUs (besides ARM) - RISC-V simplicity simply means less bugs
- kabdib 7y ago> RISC-V simplicity simply means less bugs Fewer bugs in your code, or fewer bugs to encounter in the platform? I've found that my bugs are usually processor-independent, and that most of the bugs in SOCs are not with the CPU cores, but the support components around them (e.g., DMA engines and timer registers with bizarre behavior). Well . . . and cache coherency issues. But everyone has cache coherency bugs. :-)
- garmaine 7y ago> Well . . . and cache coherency issues. But everyone has cache coherency bugs. :-) RISC-V is trying to make that a thing of the past.
- kinghajj 7y ago"Can't have cache coherency bugs, if your ISA doesn't require cache coherency!"
- garmaine 7y agoMaybe I need to elaborate. The RISC-V foundation is currently working to strictly define both strong and weak cache coherency modes, and a separate formal verification group is working to define and validate a formal model of cache coherency behavior for the RISC-V ISA. There have been numerous updates on this project at the past couple of RISC-V workshops. When this is all done, ensuring a given implementation is bug-free with respect to cache coherency will be a mechanical process (at least, that is the goal).
- pjc50 7y agoAs someone who works in a famous mixed-signal IC company, I note that almost everything I've heard about it comes from HN and not internal discussion. Instruction sets are just not where the leading edge of value creation is. And the design and manufacture costs of ICs remain pretty irreducible. People expecting lots of open source hardware to suddenly start popping up are going to be disappointed. An instruction set is an API. It's the architecture behind it that matters.
- GoblinSlayer 7y agoTargeting all use cases with x86 is not unusual?
- pjc50 7y agoI'm not sure what the argument is here?
- kevin_thibedeau 7y agoIt's going to start popping up as soon as Chinese chip manufactures get ramped onto the bandwagon. They will want the extra margin that royalty free cores give them. The rest of the world will be satisfied with cheap ARM devices.
- petra 7y agoA lot of innovation starts at universities. They seem to like risc-v. And with the ecosystem available, there's less of a need to port to ARM.
- nickik 7y agoThe problem is that you can't have open-source chips without an open-source ISA. Without an open-source ISA we can't have a open-hardware movement for silicon. Yes, the internal design is the important part, and having an ISA that is designed properly, will make that a lot easier and we have seen both high and low performance chips that can compete with ARM speeds while having far less development time. RISC-V is designed to allow individual companies to add their own secret sauce and to have a tool-chain that makes that easy. We should remember that RISC-V is still incredible young, it only just escaped officially from university 3 years ago.
- GoblinSlayer 7y agoPrevious ISAs were made for computers that don't exist anymore.
- tylerl 7y agoCost. ARM and MIPS require licensing fees, and spinning your own new architecture will make your chips irrelevant. RISC-V doesn't charge you to use their instruction set, and it's already supported by developer tooling.
- 693471 7y agoMIPS is open now https://www.mipsopen.com/ https://www.mipsopen.com/
- ncmncm 7y agoThe openness means it is accessible by academics, who are lately working hard on proving formal correctness of the spec, which we don't have for commercial designs. It is unfortunate that they froze the base instruction set before people who understand performance optimization got a good look at it. But, ultimately, if the instruction density is no worse than Intel's, it won't be handicapped by that until something else comes along. When that happens, it will make the transition to the next easier.
- greybox 7y ago404 page not found - maybe the product was de-listed?
- Randor 7y agoWell, I'm getting a 404 too so I am guessing that the page was removed.
- codetrotter 7y agoPage works fine for me. Maybe it was a temporary problem?
- omegabravo 7y agoit's still 404 for me, so I opened it in private mode and it appeared.
- talkingtab 7y agoI had the same issue until I turned off my ad blocker.
- omgtehlion 7y agoDatasheets are here: http://dl.sipeed.com/LONGAN/Nano/DOC/ http://dl.sipeed.com/LONGAN/Nano/DOC/ As from my experience with GD's STM32 clones, they did not have a real flash, but copied all your code from SPI-like internal flash to main SRAM on startup. I wonder if they did pull the same stunt with GD32V's EDIT: what is inside stm32 clone: https://zeptobars.com/en/read/GD32F103CBT6-mcm-serial-flash-Giga-Devices https://zeptobars.com/en/read/GD32F103CBT6-mcm-serial-flash-... EDIT2: original page now returns 404, it was this board: http://dl.sipeed.com/LONGAN/Nano/Spec/Sipeed%20longan%20nano%20Datasheet%20V1.0.pdf http://dl.sipeed.com/LONGAN/Nano/Spec/Sipeed%20longan%20nano... for $4.90 (https://www.seeedstudio.com/catalogsearch/result/?cat=&q=GD32VF103CBT6 https://www.seeedstudio.com/catalogsearch/result/?cat=&q=GD3...)
- kevin_thibedeau 7y agoExecuting from flash is patent encumbered.
- petra 7y agoWhat's novel about that ?
- monocasa 7y agoDo what now? People have been executing out of flash for longer than patents are valid.
- kevin_thibedeau 7y agoSTM32 has special its ART accelerator cache to prefetch instruction lines from flash and significantly reduce wait states. A clone can't replicate the same performance with a bog standard flash peripheral. https://www.embedded.com/electronics-blogs/break-points/4440388/On-wait-states https://www.embedded.com/electronics-blogs/break-points/4440...
- monocasa 7y agoI know about ART. I actually have some contributions to the STM32F4 reference manual as my team had access to pre production silicon. There's bugs in the prefetching on that thing on early revs and you need to flip a chicken bit. I still don't see anything in there that's not the usual way flash is accessed in cases where it's mapped into the address space for XIP applications. Hell, a lot of the time people will stick something nicer than a dog simple direct mapped cache like ST's implementation.
- antoniuschan99 7y agoI been using esp8266 but have been looking to learn more about STM32 and RIsc-v since its closer to the hardware. On a commercial standpoint, wroom-02 is fcc pre certified. An example of the sipeed nano dev board with WiFi on board is this, which uses esp8265 https://www.seeedstudio.com/Sipeed-MAIX-I-module-WiFi-version-1st-RISC-V-64-AI-Module-K210-inside-p-3206.html https://www.seeedstudio.com/Sipeed-MAIX-I-module-WiFi-versio... If someone were to use STM32 for business logic, why wouldnt they just use an esp8266 since its a microcontroller, wifi, and the wroom-02 is pre certified? Also, for clarification. The STM32 is based off of ARM Architechture. Whereas the Sipeed Longan Nano competes against the STM32 but is RISC-V based?
- ncmncm 7y agoA longan is an asian fruit related to the lychee. FYI ICYWW NTIM
- whydoyouasking 7y agoBeware! Opinionated comment! Seeedstudio is such ignorant to their customers. Delivery of my order failed due to local mail and person from other side of customer "support" email rejected even to write a request to mail service. I'm not talking about compensation and/or resend.
- whydoyouasking 7y agoI wonder who's that [-] was.
- marshray 7y agoAs a tinkerer: 1. I can read the official specs without agreeing to an onerous license. 2. There are several open source implementations I can choose to run on an FPGA. 3. I can choose the simplest combination of features. Want a multiply instruction, but no branch prediction? Want caching but no MMU requiring multi-level address virtualization? A large processor vendor has to employ a small army of processor designers. The trend will always be in the direction of adding more features and increasing complexity. Customers will write code to require those features, and the cycle continues. Only very rarely a fresh design will appear having the right combination of attributes to give it a chance of being a viable platform for a long time. This is what makes Risk-V attractive to me.
- fuzzybear3965 7y agoHow I can distinguish news discussing a processor core design (seemingly, usually, marketed as a "core") from that discussing hardware that I can actually buy (a processor "chip")? I would have thought that 1. https://blog.westerndigital.com/risc-v-swerv-core-open-source/ https://blog.westerndigital.com/risc-v-swerv-core-open-sourc... 2. https://greenwaves-technologies.com/ai_processor_gap8/ https://greenwaves-technologies.com/ai_processor_gap8/ and 3. https://syntacore.com/page/products/processor-ip/scr1 https://syntacore.com/page/products/processor-ip/scr1 would be pieces of hardware that I can buy. Instead, they seem to be designs for hardware which conform to the RISC-V ISA, which could then be fabbed by a semiconductor manufacturer or flashed onto an FPGA. What marketing/technical terms distinguish the designs of these systems from their implementations? "Core", "processor", "MCU"/"microcontroller", for example? Are any/all of these uniquely constrained to describing either a design (on paper) or that design's physical implementation in hardware?