Embedded distributions on Pi

[JohnBeardmore]

Is there any viable embedded Linux distribution for the Pi yet ?

Ideally I'd like something that tolerates being rebooted by cycling the power or hardware reset by watchdog timer.

I appreciate applications will loose data in some circumstances, but what I'm keen to achieve is a way of protecting the core OS files form corruption, ideally by having the core OS in a read only file system, with everything else in RAM or accessed over a network.

Obviously it would help if it was compatible with gcc binaries compiled under Raspbian, and also if it could support a reasonable IDE like codeblocks.

Thanks, J/.

[micedwards]

I'm interested in this too, and I'm willing to help on a project to make this happen if we can find any ...

[JohnBeardmore]

I was a bit stunned by the silence when I asked this question.

Maybe it's because it was a silly question in some respect, or maybe most people just aren't interested in embedded systems.

I haven't had much time to look in to this, but have you seen http://www.machinoid.com/ ?

I've only had a brief glance at their web site, but there doesn't seem to be a lot of obvious information.

I'd be very interested what you think of machinoid, or any other embedded distributions that you find.


Thanks, J/.

[ghans]

There are a lot of minimal images around ... or you could use Arch or TinyCore , which focus on extensibility and
start very "bare" .


ghans

[duberry]

i must have missed this Q
*big noise*

not shore i fully understand what "compatible with gcc binaries compiled under Raspbian" might entail

tho Tiny Core maybe worth taking a look at ( bold added )

http://tinycorelinux.net/concepts.html

Tiny Core is different because users are not encouraged to perform a 'traditional', hard-drive installation of the operating system. Sure, a hard drive installation is possible, but Tiny Core is designed to run from a RAM copy created at boot time. Besides being fast, this protects system files from changes and ensures a pristine system on every reboot. Easy, fast, and simple renew-ability and stability is a principle goal of Tiny Core.

[JohnBeardmore]

Tiny Core does look quite promising ! Many thanks !

duberry wrote:

>not shore i fully understand what "compatible with gcc binaries compiled under Raspbian" might entail

I'm assuming is that an embedded distribution won't be a great development environment. At the moment I'm developing with codeblocks, gcc, wiringPi and a couple of libraries, and can 'apt-get install' whatever I want. I assume because you get a 'pristine image every time' there is more to adding software to the TC image ?

What I assume I need to do, is compile my code on Raspbian, then copy the executables to the target embedded OS, which I guess in this case would involve incorporating them into the image from which the system boots, them patching inittab on the embedded OS to start and respawn them automatically.

Have you used TC much ? What's your experience been ? Are there other (or better !) ways of working than the one I've assumed above ?

Apart from TC, are there other embedded OSs I should look at before committing ?

Cheers, J/.

[AndrewS]

The "classic" solution to this problem is buildroot (which can run from an initramfs if your image is small enough), and there's already a few Pi-focused buildroot derivatives. And there's also lots of info on these forums if you try searching for things like "readonly root filesystem".

With regards to "compatible with Raspbian" - the big headache will be library compatibility (and not only version matching) - for reasons of space many "embedded" distros typically don't include shared libraries in the rootfs, but build all the binaries statically linked instead of dynamically linked.
Of course there are other solutions, but it all comes down to balancing memory usage / binary size / disk footprint / etc. etc. in terms of what your exact requirements are.
I haven't yet looked at TinyCore myself, but I keep meaning to...

[duberry]

> I assume because you get a 'pristine image every time' there is more to adding software to the TC image ?

indeed ! TC is smater than your average distro

graphic over view @ tiny_core_file_architecture_diagrams

adding software is easy enough
you just need to set "tce=sdXY" parameter in kernel boot option code in cmdline.txt to configure persistent storage
then you can use the TC package management tools ( gui or cli ) to search / install TCZ extension packages
eg
to load compile-essentials.tcz which "Loads essential files to compile C/C++ programs"

Code: Select all

tce-load -i -w compile-essentials.tcz 

had a quick look wiringpi-dev.tcz is available as an extension !
so

Code: Select all

tce-load -i -w wiringpi-dev.tcz 

code blocks its not in currently in the TC armv6 repo .
( tho if needed i assume it could be built easy enough )

to get stuff starting / respawning how u want it
tinycorelinux.net/wiki:the_boot_process

all credit to TCL team ( who can be found on the TC forum )
all mistakes my own

good luck !
also the corebook.pdf !!