3 ms·

Gentle reminder: you can buy dual core RISC-V chips today for $9, FPU, DSP, and TPU included, with WiFi onboard if you buy a module: https://kendryte.com/ https

by m0zg 7y ago

Gentle reminder: you can buy dual core RISC-V chips today for $9, FPU, DSP, and TPU included, with WiFi onboard if you buy a module: https://kendryte.com/ https://kendryte.com/. It won't run Linux (no MMU), but it will run FreeRTOS and TensorFlow Lite, straight from their GitHub.

jtl999 7y ago
There's uclinux, but I don't know how well it works (seems abandoned) and if there are other issues with it running on above mentioned RISC-V core.
- ronsor 7y ago
  I think it's part of mainline now (just like User Mode Linux/UML). So it's not abandoned.
  - jtl999 7y ago
    Ah, thanks
copperx 7y ago
It's not clear from the website that you can buy a module easily. Do you have to buy them in bulk?
- m0zg 7y ago
  You can buy them on Adafruit in the form of a device with battery, display and camera (but no wifi). Modules can be bought from Seeed or other usual Chinese places. No "bulk", you can even buy a single module. This, IMO, is one of the most exciting things I have seen in the embedded hardware space in years. At least all that Bitcoin money ended up producing something of value (the company that makes the chip stated out manufacturing bitcoin mining ASICs). 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...
PhantomGremlin 7y ago
It won't run Linux (no MMU) How are processes isolated from one another if there is no MMU? Is there some other form of memory protection? That doesn't seem likely? Not having process isolation really limits the applicability of the chip.
- kbumsik 7y ago
  It doesn't have processes. This looks like to be a bare-metal (or RTOS) embedded system. It usually is for running a single application so isolation between processes doesn't make much sense. FreeRTOS doesn't even have concept of process neither, but tasks, which is similar to threads with preemption and deadline. Furthermore MMU is often avoided in embedded systems because it violates hard real-time requirements: Translation table walking can take place while an interrupt occurs so it causes unpredictable worst-case execution time. In case of ARM Cortex-M and R series they have Memory Protection Unit (MPU) instead of MMU to protect critical memory region.
- Zardoz84 7y ago
  Minix v1 and some older Unix clones run very well on 8086 and had processes. MMU make it easier, faster and more secure.
akerro 7y ago
Will any BSD run on it?
- loeg 7y ago
  The modern ones (FreeBSD at least) require an MMU. RetroBSD might, if they have RiscV support? Probably not, though. http://retrobsd.org/wiki/doku.php/start http://retrobsd.org/wiki/doku.php/start (FreeBSD has RiscV support for versions with an MMU.)

by m0zg 7y ago

jtl999 7y ago

There's uclinux, but I don't know how well it works (seems abandoned) and if there are other issues with it running on above mentioned RISC-V core.

ronsor 7y ago
I think it's part of mainline now (just like User Mode Linux/UML). So it's not abandoned.
- jtl999 7y ago
  Ah, thanks

copperx 7y ago

It's not clear from the website that you can buy a module easily. Do you have to buy them in bulk?

m0zg 7y ago
You can buy them on Adafruit in the form of a device with battery, display and camera (but no wifi). Modules can be bought from Seeed or other usual Chinese places. No "bulk", you can even buy a single module. This, IMO, is one of the most exciting things I have seen in the embedded hardware space in years. At least all that Bitcoin money ended up producing something of value (the company that makes the chip stated out manufacturing bitcoin mining ASICs). 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...

PhantomGremlin 7y ago

It won't run Linux (no MMU) How are processes isolated from one another if there is no MMU? Is there some other form of memory protection? That doesn't seem likely? Not having process isolation really limits the applicability of the chip.

kbumsik 7y ago
It doesn't have processes. This looks like to be a bare-metal (or RTOS) embedded system. It usually is for running a single application so isolation between processes doesn't make much sense. FreeRTOS doesn't even have concept of process neither, but tasks, which is similar to threads with preemption and deadline. Furthermore MMU is often avoided in embedded systems because it violates hard real-time requirements: Translation table walking can take place while an interrupt occurs so it causes unpredictable worst-case execution time. In case of ARM Cortex-M and R series they have Memory Protection Unit (MPU) instead of MMU to protect critical memory region.
Zardoz84 7y ago
Minix v1 and some older Unix clones run very well on 8086 and had processes. MMU make it easier, faster and more secure.

akerro 7y ago

Will any BSD run on it?

loeg 7y ago
The modern ones (FreeBSD at least) require an MMU. RetroBSD might, if they have RiscV support? Probably not, though. http://retrobsd.org/wiki/doku.php/start http://retrobsd.org/wiki/doku.php/start (FreeBSD has RiscV support for versions with an MMU.)