Linux for a Cortex ARM processor

[mzimmers]

Hi -

I need to look at finding a Linux that is suitable for an ST Micro STM32F207 processor. Before I outline my needs, is this the proper forum for asking a question about this device?

Thanks.

[oz]

is this the proper forum for asking a question about this device?

Hello and welcome!

Yes, this is probably as good as any for your thread.

[mzimmers]

OK, cool. So here's the story: I need to program this ARM for various control functions for a modem we're building. (The ARM doesn't actually perform the modem operations.) We're designing and building the board ourselves.

From a software standpoint, our needs are modest: the ARM functions will consist of a few startup functions, and supporting two Ethernet connections. Maybe some other minor stuff.

We need:

- TCP/IP
- SNMP
- Telnet
- FTP

So it seemed like going with a Linux instead of an RTOS made sense. Someone just told me about uClinux, and I'm beginning to look into that. If anyone has some other ideas, I'd love to hear them. Just bear in mind that this device is pretty limited when it comes to on-board storage.

Thanks.

[atreyu]

Debian leaps to mind. It is as ubiquitous as ARM itself when it comes to embedded Linux.

But your limiting factor is your storage, for sure. I've used Fedora for ARM and several Debian derivatives myself (Pengutronix was one), but the Debian derivatives came with the boards, so I didn't have to do anything special to install them. It is important that you are aware of your ARM processor type (ARM11, ARM9, etc.) b/c only certain ones are supported by certain distros.

Here's a list of Linux distros put out by ARM themselves, if you haven't seen it:

Linux Support for the ARM Architecture - ARM

Check them out, maybe one of them will work, or at least give you a lead.

[mzimmers]

Our device is a "ARM 32-bit Cortex™-M3 CPU" per the data sheet. I don't see anything on that list that matches; I guess that was too much to hope for.

I'll look at Debian, though I was hoping someone had blazed a trail here; I don't think I have the time (or expertise) to do a port on my own.

Thanks for the suggestions.

[atreyu]

There has been some Linux work done for this processor already...

LinuxM3 < LinuxKernel < Foswiki

[mzimmers]

Thanks, atreyu. Please help me understand something: according to that page, I can download a kernel from arm.com/community/software-enablement/linux.php (can't post links yet), but I don't see anything on that site earmarked for the M3. What am I missing here?

[atreyu]

you're right, there is nothing at the downloads page for the M3. Instead, you need to follow the instructions in the original link i posted:

http://www.linux-arm.org/LinuxKernel/LinuxM3

in short:

• download and install an ARM tool chain
• patch and build a kernel
• build busybox (or use the pre-built one there)
• load the kernel into memory on your board and boot linux

Just so you understand, Busybox can be thought of as a tiny replacement for the GNU userland tools (sh,cat,ls,tar,gzip,login,ifconfig, etc.). it is actually one binary (busybox) and a bunch of appropriately named links to busybox (called "applets"), e.g.: there will be a link to busybox called "ls" that when run, will execute busybox and call the "ls" applet functionality. all the applets will be missing some (or much) of their functionality that exists in their GNU counterparts.

If this seems like a lot of work, perhaps you can contact the maintainer of that page, listed at the very bottom of that page. perhaps he/she can provide you with updated procedures (it was updated in 2008).

[mzimmers]

OK, I want to be sure I understand you (and the information in the link). I'm assuming that your step #2 involves the following sub-steps:

1. download a source tree
2. download the patches
3. apply the patches

If this is correct, then my question is: where should I be getting the source from? arm.com, linux-arm.org, or somewhere else?

I've downloaded and installed the MG tool chain. Evidently, only the CLI version is available at no cost. Do you happen to know whether MinGW would work as a toolchain? If so, I can use Qt to build this.

Thank you.

[atreyu]

If this is correct, then my question is: where should I be getting the source from? arm.com, linux-arm.org, or somewhere else?
I would

If i am reading that page right (it is kind of confusing), then I would follow the link suggested here:

Alternatively, the Git tree hosting the Linux patches is available from (currently based on Linux 2.6.33)

http://www.linux-arm.org/git?p=linux-2.6-stable.git;a=shortlog;h=refs/heads/2.6.33-arm

and then d/l the snapshot link at the far right on the first line of that page, the line looks like:

2010-05-21 Catalin Marinas Linux 2.6.33-arm1  2.6.33-arm v2.6.33-arm1 commit | commitdiff | tree | snapshot

the file you d/l would be called:

linux-2.6-stable-729b792.tar.gz

I've downloaded and installed the MG tool chain. Evidently, only the CLI version is available at no cost. Do you happen to know whether MinGW would work as a toolchain? If so, I can use Qt to build this.

i doubt it. how about this link, for the CodeSourcey cross-compiler toolchain?

http://www.codesourcery.com/sgpp/lit...ux-gnu.tar.bz2