Hacker News Reader

Comment by ishikawa | Hacker News Reader

This can be pretty interesting for inexpensive IoT and IIoT devices.

No, this is jut a toy, it would never be used for real IoT or IIoT devices.

There is no need to dynamically load any code on these type of devices, you would generally just use eXecute-In-Place (XIP). The type of applications you develop for these devices simply do not require UNIX like features (multi-user, etc). Many more appropriate OS'es exist for this to be taken seriously.

I am not saying it's a good idea, but you have Minix (multi-user Unix, it can even compile itself) in (all?) Intel 64 bit chipsets.

This comment is misinformed. Unix has always been multi user, and has always (aside from earliest days before anyone heard of it) been able to compile itself. Minix does not stand for multi-user Unix.

https://www.levenez.com/unix/

https://www.tuhs.org/Archive/Distributions/Research/Document...

The reference is presumably to Intel's use of Minix in its CPUs - see, e.g., https://www.zdnet.com/article/minix-intels-hidden-in-chip-op... - as an example of a place where a multi-user OS (that can compile itself...) might be used for what might seem like an embedded-type application.

> No, this is jut a toy, it would never be used for real IoT or IIoT devices.

There's lots of outrageous stuff inside today's consumer products. What makes you so sure that this won't be used in a real (whatever that means) IoT or IIoT device by someone?

I think this implementation is intended as a toy or proof of concept, maybe something like this could be used but I doubt this specific one would ever be used in a product. Seems like a lot of overhead for a single-purpose microcontroller. PIC32 is also not a super popular architecture, especially not in Asia (not saying it's bad, just that ARM has pretty much won that fight already). I'm not a super expert on that sort of thing, but casually I can't remember ever seeing a PIC32 in the wild.

Because I design this sort of stuff for a living and have done for over twenty years. As a realistic product solution, this has no benefits over existing widely supported solutions that are more targeted at this level of device.

For example... it can work in 128KB RAM. If you're using 128KB just to run the OS, thats completely wasted RAM that could be used by your application. This really counts when you're making 100'000 of these devices and are paying for every byte. You don't waste valuable resources on desktop-level abstractions. That would make for a very expensive product.

Many people might think you're talking figuratively about paying for every byte. I'll add for others that 8-16-bit MCU's still sell billions of dollars of volume specifically to increase profit per unit by using tinier, cheaper chips. Likewise, stuff like eCos lets you include just the software you need in the RTOS to further shave off ROM or RAM needs. This helps per unit since suppliers often charge extra for extra RAM/ROM on a specific chip. Finally, reliability and security can improve a bit by simply having less software or hardware to screw up.

There already exist a number of more suitable operating systems for these purposes that require much less resources e.g. NuttX, RIOT, Contiki, Zephyr. Running this requires at least 128k of SRAM and 512k of flash just for the OS, so you're looking at the expensive end of the uC range to begin with.

Also there's FreeRTOS: https://freertos.org/

Yes, I didn't include it as it's not well suited to IoT "out of the box" due to lack of wireless drivers, and very limited network stack. I do enjoy it's simplicity and have used it for many non-networked projects (the Hungarian notation is brain damaged though :().

A FreeRTOS with that stuff on a popular board sounds like a good project or business opportunity if Wittenstein isnt on it already. ;)

Reply on news.ycombinator.com