Apple to Move a Part of Its Embedded Cores to RISC-V • Hacker News Board

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#21

Post by Someone » Sat, Sep 17, 2022, 5:16 AM UTC

Taniwha wrote: post #18

kmeisthax wrote: post #6

Earlier quoted context omitted.

One thing to note is that RISC-V is only royalty-free for people making custom silicon implementations - i.e. the equivalent of an ARM architectural license. You still have to design the cores and that's the really hard part, moreso than designing the ISA. Apple is in a unique position where they have all these Cortex cores for various reasons, but also have the resources to actually design a RISC-V implementation th…

There's lots of open source RISC-V cores - but can't be any fully OS ARM ones (even if someone's made a n OS ARM core you still have to pay ARM a royalty) The big advantage to rolling your own private ISA is that there's already a rich compiler and O/S ecosystem for RISC-V while if you do use RISC-V it's all already there for you. It really does feel like a second generation 'barn raising'

> but can't be any fully OS ARM ones (even if someone's made an OS ARM core you still have to pay ARM a royalty)

Wait long enough and you can. Even if you can’t work around them, patents expire, and you can copy the instruction set for reasons of compatibility.

Trademarks don’t automatically expire, though, so unless the trademark gets genericized (https://en.wikipedia.org/wiki/Generic_trademark) what you can’t do is call it an ARM CPU.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#22

Post by sitkack » Sat, Sep 17, 2022, 5:22 AM UTC

userbinator wrote: post #20

arcticbull wrote: post #17

Earlier quoted context omitted.

I'm pretty sure they're all ARM. Why would they be 8051s? Are there any sufficiently performant 8051 cores?

Here's one with a 250MHz 8051: https://github.com/flowswitch/phison/wiki/PS2303 They don't need anything as powerful as ARM (and thus avoid the licensing fees), and it's a very price-sensitive market, so a fast 8051 + accelerator hardware is enough. No doubt some of the more expensive ones may be ARM-based, but I think the 8051-based ones far outsell them in volume.

RV32 will turn out to be the 8051 of the present. The 8051 was the Doge Dart of embedded automation. I bought a book in Vietnamese in Vietnam in 2005 on embedded development hardware and software for the 8051. If the diagrams were any indication of the quality, the writing was excellent.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#23

Post by phire » Sat, Sep 17, 2022, 5:26 AM UTC

kmeisthax wrote: post #6

Taniwha wrote: post #2

10 billion RISC-V cores were shipped last year - mostly you wont see them because they're heavily embedded - in disk drives/etc - used to be every flash drive had an ARM core in it and paid a few pennies to ARM, that's likely to change quickly

One thing to note is that RISC-V is only royalty-free for people making custom silicon implementations - i.e. the equivalent of an ARM architectural license. You still have to design the cores and that's the really hard part, moreso than designing the ISA. Apple is in a unique position where they have all these Cortex cores for various reasons, but also have the resources to actually design a RISC-V implementation th…

The article is wrong, Apple don't really use ARM's Cortex cores within the M1

They already have a their own custom low-power arm64 core design for running these firmware tasks. They have about a dozen of them scattered around the M1, on top of the massive P and E cores.

There are still a few actual ARM inc designed cores spread around the motherboard, in various devices. But inside the SoC, most (if not all) are Apple's own design.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#24

Post by wyldfire » Sat, Sep 17, 2022, 5:27 AM UTC

teitoklien wrote: post #19

tiffanyh wrote: post #13

What benefits does RISC-V have over ARM besides it being open/free?

What benefits does Linux/BSD have over Windows, as a highly productive development environment outside of all the possibilities it had opened by being open/free ?

IMO the comparison is similar but it's just not quite the same thing.

Don't get me wrong - it's a big deal to have this popular open ISA. But I just don't think it's anywhere near as big a deal as Linux is/was.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#25

Post by sitkack » Sat, Sep 17, 2022, 5:27 AM UTC

tiffanyh wrote: post #13

What benefits does RISC-V have over ARM besides it being open/free?

smaller instruction set, Arm has grown, reference manual is over 6k pages

smaller easier to read specs

easier to get new features ratified, org is a steward, isn't seeking rents

easy to add custom instructions

lots of OSH implementations to choose from

large 3rd party ecosystem, IP, compilers, OS, etc.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#26

Post by dkjaudyeqooe » Sat, Sep 17, 2022, 5:37 AM UTC

kmeisthax wrote: post #6

Taniwha wrote: post #2

10 billion RISC-V cores were shipped last year - mostly you wont see them because they're heavily embedded - in disk drives/etc - used to be every flash drive had an ARM core in it and paid a few pennies to ARM, that's likely to change quickly

One thing to note is that RISC-V is only royalty-free for people making custom silicon implementations - i.e. the equivalent of an ARM architectural license. You still have to design the cores and that's the really hard part, moreso than designing the ISA. Apple is in a unique position where they have all these Cortex cores for various reasons, but also have the resources to actually design a RISC-V implementation th…

The RV arch is much simpler than ARM and there are many more options in the market for licencing designs, besides the option of designing your own.

That's the real difference: RV is a real market with multiple vendors whereas ARM arch is more or less single vendor lock-in.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#27

Post by userbinator » Sat, Sep 17, 2022, 5:52 AM UTC

sitkack wrote: post #22

userbinator wrote: post #20

Earlier quoted context omitted.

Here's one with a 250MHz 8051: https://github.com/flowswitch/phison/wiki/PS2303 They don't need anything as powerful as ARM (and thus avoid the licensing fees), and it's a very price-sensitive market, so a fast 8051 + accelerator hardware is enough. No doubt some of the more expensive ones may be ARM-based, but I think the 8051-based ones far outsell them in volume.

RV32 will turn out to be the 8051 of the present. The 8051 was the Doge Dart of embedded automation. I bought a book in Vietnamese in Vietnam in 2005 on embedded development hardware and software for the 8051. If the diagrams were any indication of the quality, the writing was excellent.

I highly doubt it. As "reduced" as RISC-V is, 8051 is still tiny in comparison.

8051s are used in applications where a 4-bit MCU (yes, they do exist and are still in widespread use) is not quite enough, or they'd have chosen one of those instead.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#28

Post by cestith » Sat, Sep 17, 2022, 6:29 AM UTC

sitkack wrote: post #25

tiffanyh wrote: post #13

What benefits does RISC-V have over ARM besides it being open/free?

smaller instruction set, Arm has grown, reference manual is over 6k pages smaller easier to read specs easier to get new features ratified, org is a steward, isn't seeking rents easy to add custom instructions lots of OSH implementations to choose from large 3rd party ecosystem, IP, compilers, OS, etc.

To be fair, even with a closed ecosystem for the cores themselves there is a large third party ecosystem in compilers, OSes, support hardware, and documentation around ARM these days. It's interesting how quickly all of that popped up around RISC-V the past few years though. ARM has had decades getting where they are with the ecosystem around their cores.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#29

Post by rwmj » Sat, Sep 17, 2022, 6:35 AM UTC

kevmoo1 wrote: post #3

I wish I could buy stock in RISC-V (in the abstract). See also today: https://twitter.com/SiFive/status/1570880204804849671

Could you join VC funds which are investing in Rivos/Ventana/SiFive/etc? (Genuine question - I have no idea if this is possible or not)

A lot of the RISC-V action is going on in China which is obviously rather more difficult. Over there much of that is funded by the Chinese state.

Re: Apple to Move a Part of Its Embedded Cores to RISC-V

#30

Post by rwmj » Sat, Sep 17, 2022, 6:38 AM UTC

tiffanyh wrote: post #13

What benefits does RISC-V have over ARM besides it being open/free?

It's completely permissionless. Grab an open source core, tweak it how you like, and move into production. No one will ask you to sign a licensing agreement or pay any license fees.

Depending on what you're doing this may or may not be an advantage, but it's certainly a large difference from Arm. It could lead to innovation happening more quickly since there's no need to wait for a gatekeeper, it's unclear at the moment how much that matters.