Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The $8 Linux Computer

thelittleengineerthatcould.blogspot.com

Post reply on HN
Print view View original

31–40 of 166 posts

Re: The $8 Linux Computer

#31

Post by wzdd »

teraflop wrote: post #2

Based on a brief bit of googling about this board's CPU (the Bouffalo Lab BL808), it seems to have one RV64 and two RV32 cores. The RV64 core may be capable of running RV32 machine code, if the OS sets various flags correctly, but the reverse isn't possible without emulation. How does Linux handle this? Can you just run an executable and have it automatically scheduled onto whichever cores can execute it? Wouldn't th…

Side note, but someone linked a great talk by OS researcher Timothy Roscoe the other day about a) the increasing heterogeneity of our computing devices, b) Linux's inability to really support same, and consequently c) Linux being used on the device, because the device has to "run Linux", but in increasingly smaller and more walled-off spaces, leaving board management which you'd normally think of as an "OS task" to device drivers or onboard firmware. The non-Linux-running processors on the board run an RTOS or whatever.

This would seem to be what's happened here with Linux running on, and really only in charge of, a small portion of the SOC. https://www.usenix.org/conference/osdi21/presentation/fri-ke...

To paraphrase what he says at the end of the talk, it would be a great idea to think about the kind of OS which could take these three cores properly into account.

Re: The $8 Linux Computer

#32

Post by bmitc »

nsteel wrote: post #30
iamflimflam1 wrote: post #28

You can get a pi zero w for $10

The RRP is now $15, if by some small miracle you find one in stock somewhere. https://www.raspberrypi.com/news/supply-chain-update-its-goo...

I'm a bit over Raspberry Pis at this point. They're impossible to find, and their performance is terrible. I tried getting back into one of my Raspberry Pis from scratch just earlier today, and even with setting up the OS from scratch and the most up to date version, it was unbearably slow. So slow as to be unusable for even the most simple tasks. So that kickstarts forum hopping trying to figure why, and there's laundry lists. It's just a massive time sync. I've decided to upgrade to a Dell or Lenovo mini PC for some desktop Linux needs, where I need a GUI, and go with other embedded solutions over Raspberry Pis or relegate them to headless only uses.

Re: The $8 Linux Computer

#33

Post by pantalaimon »

blippage wrote: post #19
boojums wrote: post #3

Earlier quoted context omitted.

One proposal I saw was to treat the RV32 core like a microcontroller or as a dedicated co-processor. https://www.robertlipe.com/bl808-not-symmetric/

Let me see if I have this straight ... it's a device that can run a general OS like Linux, but say, have a core that could be run real-time, with all the goodies like timers and stuff that we expect from microcontrollers? If so, then that would be pretty awesome. I think that people have been trying to get real-time working on Raspberry Pis. It seems that they get kinda close, but never manage to get all the way.

This is actually a common pattern you get from multiple vendors.

Re: The $8 Linux Computer

#34

Post by pantalaimon »

pjmlp wrote: post #11

> It looks like a microcontroller, but behaves like a UNIX machine. While a great achievement and very interesting article, the same can be said from many RTOS that offer POSIX compatibility.

The difference is that with RTOSes you typically link the application together with the OS, whereas with Linux you can dynamically load applications at run-time.

Re: The $8 Linux Computer

#39

Post by pjmlp »

pantalaimon wrote: post #34
pjmlp wrote: post #11

> It looks like a microcontroller, but behaves like a UNIX machine. While a great achievement and very interesting article, the same can be said from many RTOS that offer POSIX compatibility.

The difference is that with RTOSes you typically link the application together with the OS, whereas with Linux you can dynamically load applications at run-time.

Like everything in computing, it depends.
Post reply on HN