openc910 VS omap-image-builder

> I'm pretty sure that SiFive isn't allowed to sell their RISC-V core designs to any Chinese company already.

The JH7110 SoC from the Chinese firm Starfive uses SiFive's U74 core. Eswin, also Chinese uses SiFive's P550 core in their upcoming EIC7700 SoC.

> All Chinese RISC-V core designs have been proprietary designs thus far.

There is the OpenC910 [1] and OpenXiangShan [2].

[1] https://github.com/T-head-Semi/openc910

Note that the C910 CPU cores used in this chip are in fact open source:

https://github.com/T-head-Semi/openc910

(C920 is just C910 plus RVV draft 0.7.1 vector unit which pretty much no software uses anyway, sadly)

The Milk-V Pioneer uses a C910 CPU, which has been open sourced by t-head: https://github.com/T-head-Semi/openc910

More precisely, a Chinese university assembled a rack containing 48 [1] commercially available SBCs [2], each with a Chinese-designed and made SG2042 SoC with 64 C910 CPU cores. The C910 was designed in China in 2018/19 and open-sourced in October 2021, on Microsoft's github site.

https://github.com/T-head-Semi/openc910

The SG2042 is the most powerful RISC-V SoC available today.

In which direction is the technology transfer going?

[1] or possibly 24 dual-socket boards, shown at the RISC-V Summit China in August

[2] get your own here https://www.crowdsupply.com/milk-v/milk-v-pioneer

For "coming down the pipeline" they're essentially free.

Today, the c910 is an Apache 2, hardware proven out of order core on GitHub here https://github.com/T-head-Semi/openc910 a little slower than an RPi3's core.

Here is the source code* for the CPU:

https://github.com/T-head-Semi/openc910

* AFAIK they didn't opensource the pre ratification vector extension implementation they ship with the taped out chip.

The source RTL for the roughly Arm A72-equivalent cores used in this were open-sourced several years ago.

https://github.com/T-head-Semi/openc910

The same cores are used in the 64 core SG2042 workstation/server SoC.

It's a shame, because it was the best design from ARM; they're now focusing on Cortex-A7x and Cortex-X, which aren't anywhere as power efficient[0].

Meanwhile, their revised Cortex-A57 has been surpassed in performance/power/area by several RISC-V microarchitectures, such as SiFive's U74[1], used in the VisionFive2 and Star64, or even the open source XuanTie C910[2][3].

0. https://www.youtube.com/watch?v=s0ukXDnWlTY

1. https://www.sifive.com/cores/u74

2. https://xrvm.com/cpu-details?id=4056743610438262784

3. https://github.com/T-head-Semi/openc910

Yes, Robert C Nelson's OMAP Image Builder is excellent. You can use it to build Debian or Ubuntu images for the Ti AM335/OMAP (e.g. BeagleBone Black) SoM:

https://github.com/RobertCNelson/omap-image-builder

I believe Robert is an applications engineer with Digikey, but he does stellar work on this, thank you RCN!

My gut feeling would be no. Some developers are trying to make "upstream" changes and driver support for certain Android devices. You can find out more in r/postmarketos. But the tl:dr of it is if postmarketos, or a mainstream kernel can run on the Android device, you could probably run another distro if you respun it. See here for more info

Robert C. Nelson has been doing a stellar job of maintaining the omap-image-builder repo:

https://github.com/RobertCNelson/omap-image-builder

(and https://elinux.org/BeagleBoardUbuntu)

It's pretty easy to use to build an image for Debian Buster/Stretch or Ubuntu Bionic Beaver, he has various configurations that cover IoT, console only/headless, GUI and a few other combos. It's pretty easy to create your own config with the Kernel and packages that you want.

The images can be used for flashing to the eMMC via an SD card (or via USB).

I've found images built this way to up very up to date and absolutely rock solid thanks to Robert's curation.