LINUX for embedded ?

Hi all

LINUX for embedded, whats the big deal ?

What is the big advantage of LINUX ti embedded
vs the OSless code for embedded ?


Elico

Are you looking for linux distributions for embedded systems? If so,
what architecture? If it is ARM, there is:
APEXAR PDK
Android
Arch Linux ARM
Ångström
CRUX ARM
BackTrack
Chrome OS
Debian
DSLinux
ELinOS
Fedora
Gentoo
GoboLinux
iPodLinux
Maemo
MeeGo
Mer
MontaVista
PuppyLinux
RedSleeve
Slackware
T2 SDE
TimeSys
Ubuntu
webOS
Wind River Linux

My question is general .

I did prctice with SUSE version of linux.

I still ask my self why not OSless C code ?

Elico

Because, once the 'OSless C code' begins running...
then it is no longer OS-less... the underlying functions/procedures that do the interaction(s) with the hardware ARE the OS...
the intermediary between the user and the system.

This is particularly true since the code will likely run till it is shut off...

I see

So what is the real advantage of LINUX based embedded board ove
a bare board like ARDUINO for example .

Elico

On a bare board only programmed by you you have to write the drivers for all components yourself. If you later have to change the platform for whatever reason you have to redo all that work. In opposite to that Linux abstracts you from the platform and you can concentrate on your application. As long as your new platform also supports Linux you can still use your application, maybe with some minor adaptions.

The two keywords here are fast development (the OS already exists) and abstraction (changes are easy to compensate), keeping the development costs as low as possible.

Yes but

If the absolute adreeses of hardware ports are different
you have to edit the drivers when changing board , am I right ?

Elico

Why would you? You can take the Linux harddisk out of your PC and put it into a PC with different hardware and it still works (if you don't use proprietary drivers). It is the same if you use Linux on a embedded system. Even if you have a special driver for one of the devices on the platform written yourself, if you have done it in a proper way you shouldn't have any problems and even if you have they should be solved with some minor corrections. If you have a PC with several PCI cards and you swap them in their slots they get different absolute hardware addresses and still work.

Many thanks

Please let me know how can I prctice the LINUX command set without a board .
Is there any free LINUX simulator or something alike ?
Elico

What do you mean with "command set"? If you just want to learn the Linux command line you can use any distro you want, you don't need to do that on an embedded board.

OK thanks

That will be all .

Eliahu

Linux, like any other OS, provides a standard set of services available to application software. In Linux, that set of services is very rich, and covers process control, memory allocation, all hardware access, networking, filesystems, interprocess communication, etc. It exposes a standardized ABI which application software uses to access all of the services porvided by the OS. All of this is provided by the Linux kernel, which actually IS the OS. All of the rst of the userspace stuff we've come to expect in a GNU/Linux system is well, just userspace programs.
You can write everything from scratch, forsaking all of the benefits of a mature OS. In smaller systems, this is the expectation. I think such systems are becoming less popular, as the price and size of relatively powerful systems (SoC's and SoM's) has dropped dramatically in recent years.
--- rod.

Thanks
Elico