Bootable CompactFlash Cards For Handhelds?

An Anonymous Coward asks: "Why haven't Compaq, HP and others provide an option in BIOS to boot from from a Compact Flash card in order to speed Linux acceptance and development for handhelds like the IPAQ 3600 series? Are there technical reasons? I some of you have to be drooling over the possibility of Linux on these babies - and yes I know about the great work at handhelds.org - but a worrisome thing is that currently, once you burn flash in the unit, there is no going back. If these companies would provide that option, the development of alternative OS's to winCE would speed up! Want to try a new kernel? Replace the CompactFlash card."

Comments

Booting CF

[emag]

I can't think of any technical reasons for not being able to boot from a CF disk. As a matter of fact, I've got a couple SBCs (single board computers) that can boot from CF sitting next to me on my desk right now.

About the only think I can think of for handhelds is either the cost of developing this capability, since more handhelds are pretty much custom hardware.

Does anyone know where the TRG SuperPilot stands on this? Or any other handhelds?


--
It's pretty pathetic when karma can drop when you do nothing

I asked the handhelds list...

[azephrahel]

I'm only posting this out of respect that the author of this e-mail stated it much better than I can paraphrase it. The lines with > on them are from my origonal e-mail to the handhelds list.
From how I read his response, there are some programming limitations that make it difficult (if not impossible) to get it working.

>Has anyone been sucessfull in booting linux on the
>ipaq off of a ramdisk? I'm terrified of flashing my
>ipaq, for fear I will end up with a 500$ paperweight.
>For those of us with some type of extra storage,
>microdrive, large flashcard or Iomega Clik, I imagine
>this would be much safer. Boot linux kernel into
>ramdisk, load driver, mount drive, free-up some ram.
>Anyone tried this? Is there a bootloader?

The short answer is no.

If you want to see what is involved in making this work, take a look
at the bootloaders for Linux VR and NetBSD/hpcmips, and in how the
link address and memory maps of the respective kernels differ from the
default Linux and NetBSD ones.

All the earlier WinCE machines had mask ROM, so you had to be able to
load on top of CE.

Linux VR looks like it can use the bootloader from NetBSD/hpcmips, so
you could just port that one to the SA-1110.

>What about netbsd? I've heard there was netbsd for
>the ipaq, but havn't seen it yet.

The NetBSD port is being written to work the same way as Linux for the
iPaq.

Robert Swindells

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Re:I asked the handhelds list...

[Bryan Andersen]

Buh!, Why not?

Why not make a WinCE app that goes and loads Linux off the CF card, and in the process takes full controll of the device? What's stopping that?

Two points

[Ledge Kindred]

One: there are a number of people working on making the H3600 able to boot Linux from WinCE off of a CF device. As the handhelds.org site says, "A lot of people are very interested in this option." and "We expect that once this feature becomes available, the number of people running Linux on their iPAQs will increase at least an order of magnitude, possibly two." Personally I agree. If Ihad any skill whatsoever in this area of programming, I'd be working on making it happen myself.

It's certainly DO-able, as evidenced by the fact that the handheld.org guys can dump out of WinCE, from WinCE, to load the boot monitor you use to load Linux into flash. It's just a matter of someone having the time to come up with all the proper bits and bytes to make it happen.

Two: I've personally slapped linux onto my iPAQ (yes I have one, drool over it!) and successfully restored WinCE without a hitch. It's a little scary the first time, but so's swimming in the deep end. It's nothing that someone who's successfully compiled their own kernel isn't capable of doing. (Notice how I don't say it's EASY, but its certainly straightforward and not at all scary if you pay attention. I'll admit that it is definitely slow going, trying to pump 16MB across a 115k serial link, though.)

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