RISC-V openness controversy


I found this thread a bit disturbing because hardware openness of RISC-V is the most important feature for me.

I’d be glad to hear some official statement…

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Could you elaborate on when you mean by “controversy” there? Maybe I’m missing something but I don’t see anything controversial in the mailing list you linked to. Except some guy wants more things to be open source than they are.

The RISC V is an open, free to use, specification for a processor instruction set architecture. One can build processors in ASICs or FPGA or whatever that comply to that ISA specification and use them however one likes without any cost, licence, royalty, patent, worries or any strings attached.

RISC V does not imply anything about the openness of the processor design that you or anyone else comes up with. There are RISC V implementations that are open sourced, there are RISC V implementations that are closed.

As far as I understand the SiFive devices are implementations of the Open Source RISC V design they use. But they may contain other closed IP blocks within the SoCs. Please correct me if I am wrong.

One can liken this to the situation with C/C++ compilers. The C/++ language is an internationally standardized and open specification. There are open source implementations of C/C++ compilers, like GCC and Clang/LLVM. But there are also closed source C/C++ compilers.

Or we can liken it to the Linux kernel. Linux is an Open Source OS kernel but most of the world is using it with some closed source drivers and often firmwares for various devices. From WiFi adapters to graphics cards.

Where is the controversy in all of this? Seems clear enough.

Certainly we all want more things Open Sourced. Ultimately everything. That may not actually be totally possible at this time.

The HiFive1 crowd supply page says:

Open-source RTL! The FE310 is the first open-source RISC-V SoC available in industry. SiFive has contributed the FE310 RTL code to the open source community. That means you can see what’s inside the chip and completely understand how the hardware works.

The HiFive Unleashed crowd supply page says:

…over a year ago when we introduced the open source, Arduino-compatible HiFive1 dev board based on our Freedom Everywhere line of 32-bit microcontrollers. Today, we’re proud to be doing the same thing with our Freedom Unleashed 64-bit, Linux-capable system-on-chip (SoC) platform.

Same thing? Most people would interpret that as meaning " Open-source RTL!" and that’s what most people still believe to this day. Or if not, at least something close to it. At the very least it should follow the basic principles of the term “open source” which is plastered all over the crowd supply page.

People who support the freedom and open movements, don’t always mind too much if the RTL is not open. The worst and most insulting thing a hardware company can do is put closed source software into the hardware that cannot be removed. But that’s exactly what they did with the Unleashed, even after they claimed to be all about “open source”!

SiFive must clarify their description of the Unleashed, and make it clear on the crowd supply page that the Unleashed contains closed source software that is required for booting, and cannot be removed. Knowing this is very important to the freedom and open crowds. I hope SiFive does the right thing!

There was a statement made in another thread

Storm in a tea cup then.

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The 2nd statement in that thread is very good and lucky news! Especially after that terrible 1st statement. It would’ve never happened without the controversy.

In summary, they say they will release the source code for both the ZSBL and FSBL “shortly”!

The ZSBL and FSBL are the only parts that are currently closed source, and the ZSBL also happens to be in the rom, which makes it especially important.

Just in case folks on this thread missed it, these were released last year: https://www.sifive.com/blog/an-open-source-release-of-the-freedom-u540-c000s-bootloader