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Linux To Gain Another Chip Family
An anonymous reader submits "Freescale will unveil the first ColdFire processors ever to include a memory management unit (MMU), and therefore able to run full-scale Linux, this week at the Embedded Processor Forum in San Jose, Calif. The chips cost $17 - $25, and are used mostly in industrial control and factory automation. Simultaneously, Freescale tools subsidiary Metrowerks announced plans to offer Linux development tools for Coldfire chips, which previously had been restricted to running uClinux due to the lack of an MMU."
These chips, distantly related to the 68k motorolas, were once touted as a possible upgrade path for new Amigas in the mid 1990s. Hopefully with these new ones, the more modern AmigaOS4 can be ported to them, and continue the heritage. At the moment the only stock available is AmigaOne G3, G4 and mini-itx PPC boards, which are artificially inflated in price by the apple/ibm/motorola consortium.
I thought I knew which processors were important in the embedded world. What exactly is Coldfire, and why does it matter compare to ARM and Motorola's offerings?
I realise that Yet Another Embedded Processor that can run all of linux is a good thing. I just don't see why that is important, since the difference between embedded and desktop processors has been diminishing sharply.
Huh? Metrowerks produces apple development tools, and they dabble in linux/embedded development tools. I'm pretty sure that Metrowerks is not a freescale subsidary. See for example this PR.
freescale is a subsidiary of motorola, here is homepage for coldfire.
Marge, get me your address book, 4 beers, and my conversation hat.
I want to build a low cost Computer Automated Dispatch system with just the basics for low income firehouses, police stations, and hospitals. This chip might just fit the bill. I was going to go with Transmeta or a low end X86 processor.
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Yeah but do they run... oh... wait... nevermind.
Since when has this country used intellectual elite as a pejorative term?
Other key features of the new MCF547x and MCF548x ColdFire processors include on-chip FPU and eMAC
Dammit apple, I just bought a brand new eMac only months ago, and now they're putting them on-chip for under $30!
I added support for ColdFire processors to Linux years ago. This won't be new. It was added to Linus kernels in the 2.5 series, and is fully supported in the 2.6 kernels for all the older ColdFire parts (5206, 5249, 5272, 5282, 5307, 5407). Ofcourse the older parts did not have an MMU.
Look under the arch/m68knommu branch for all the architecture support...
This isn't some fly-by-night chip maker.
First, let's compare apples to apples. These new ColdFire processors run at 266 MHz and cost $20-27. The 266MHz PowerPC MPC5200 (also from Motorola) costs $27.
Even the desktop-class PPC 750s and 74xxs aren't expensive if you buy them in volume. The AmigaOne is expensive because it is a niche-of-a-niche product, not because Moto is ripping people off.
There is a really big difference between embedded processors and mainstream CPUs.
The biggest is that power consumption is really important in the embedded world. Sometimes you can only get so much current to a board, or you can't run fans.
Typically, embedded processors can run without support chips. Many have built in memory controllers and I/O.
Another thing is the MMU. A lot of embedded processors have MMUs (I think most of the PPC ones do), but OS support for them is a bit lacking (or it was until recently). But at times, the MMU can get in the way
IMHO, I would never run linux in an embedded product, other than simple internet appliances or where realtime isn't required. Commerical RTOSs like VxWorks really are worth it for most embedded applications.
(S(SKK)(SKK))(S(SKK)(SKK))
ColdFire was created like this:
1. start with 680x0
2. rip out the bloat (MMU, fancy FPU, etc.)
3. redo the opcode-to-binary mapping
Often you can use 680x0 assembly code on
a ColdFire chip, though you'll need to run
it through a ColdFire assembler. You can't
just grab a binary.
Don't click that link. If you check your status bar, it's "http://www.google.com/url?sa=D&q=http://www.peopl esprimary.com/?n=Sarojin", which redirects to http://www.peoplesprimary.com/?n=Sarojin, not a Google search. The page is nasty
Their shell is an abomination. Their filesystem
is plain old DOS FAT, optionally with an
incompatible long-filename feature. The "mount"
command (function? all the same...) is totally
defective, doing some kind of dumb text substitution
instead of real mount points. Memory support is
terribly limited -- is 32 MB enough for you?
For the cost of VxWorks, you can get a bit of
extra memory for running Linux. You'll also save
on development costs that way.
If you'd really prefer a tiny OS designed for
strict real-time from the start, use eCos.
It's free even.
"Finally! A day will come where I can get a processor with MM and NX bit on a mobile motherboard featuring MXM interface. "
Rats, my universal translator is broken.
"Derp de derp."
Another chip family? No, unless you think Intel XScale and TI OMAP are in different chip families. The ColdFire chips are just another example of the m68k family, like the DragonBall chips are.
What's the cheapest embedded linux board (inluding cost of flash ram .. oh yeah must have ethernet)?
.. seems like the minimum amount to spend would be over 200.
Anyone have ideas?
I am checking on google
Innovation like this underscores the need for relying on free software (or, put differently, the problem with relying or recommending non-free software). It's an easy trap to get into when you use an i386 GNU/Linux distribution (as most GNU/Linux users do, I suspect) because there are so many opportunities to get hardware that only fully work with non-free software (like nVidia video cards that require non-free kernel driver software to operate fully). When you become dependent on non-free software you lose portability which prevents easily moving to interesting hardware like this one. Non-free video and audio codecs are similar; if you base your work on some Microsoft library for decoding audio or video you won't easily be able to read those files on a non-i386 platform.
Software proprietors won't supply the wide range of support the free software community does. Software proprietors won't give you the power to provide your own support or buy it from programmers and sysadmins in the free marketplace.
Digital Citizen
We looked at VxWorks for our first-ever embedded project. When we found out there was no Perl for VxWorks, nor any chance of ever, ever having Perl on VxWorks, we quickly abandonded VxWorks in favor of Linux.
We've have no problems whatsoever using Linux as an embedded OS. Plus, we get to write much of our code in Perl as well. This is as it should be.
In the course of every project, it will become necessary to shoot the scientists and begin production.
Rush fans everywhere rejoice!
uCLinux is a port of Linux to CPUs without an MMU. Without an MMU, the chips don't support the convincingly simulated parallelism of fork(), rather just the nominally similar (blocking) vfork(). What other compromises must an application concede when running under uCLinux, rather than a "full" Linux kernel?
--
make install -not war
They try to fool you into thinking they are. But they aren't. They are an entirely different architecture that uses similar nmeumonics and addressing modes.
Even the hexidecimal encodings of those instructions (i.e. the machine language) is dissimilar from 68K machine language.
ColdFire is a strange product, I moto has been pushing it for some time now. I'm not sure why it is still around.
is send out signals to activate alarm clocks, lights, bells, sirens, speakers, and display a message on a computer with details of the 911 emergancy.
We are talking about something that an original Palm Pilot or security alarm system can do. An 8 bit processor may be too underpowered, but I believe this is more of a 16/32 bit hybrid like a 68K processor. If you examine ADT, and other boxes that security alarm systems use, you won't find the most powerful processors in those. Maybe a 16 or 32 bit processor with low end speed.
Now building a 911 CAD box with a Pentium 4 is overkill, and unless you really need the horsepower, it would be overpriced.
You have missed the point, I wanted to make a low cost, no frills, version of a 911 CAD box. Other companies have this box but charge $1000USD to $4000USD or more for each box, and some emergency providers cannot afford that.
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That was my original idea to use a low end X86 processor. Embedded Linux already exists for it, and if SCO gets their way we can always change to BSD Unix.
;)
Anyway an original socket 7 X86 chip should work fine for low end 911 Computer Automated Dispatch. That is if they still sell them.
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