Re: Looking for a well supported ARM device for demo usage
On Tue, May 3, 2011 at 11:20 PM, Phil Endecott
<spam_from_debian_arm@chezphil.org> wrote:
> I don't think any of the other choices (Panda, iMX53 board, AC-100, TrimSlice)
> could be described as anywhere near "very well supported"; they are at best "can
> be hacked to work".
yehh, this is just... part of how ARM embedded systems are: there
*is* no "BIOS", each chip is different, and each system using them is
radically different. this situation just isn't going to change,
period, and you (rhetorical and plural "you") just have to suck it up
and put up with it.
... i'm trying to remember what was done for the CT-PC89E... it
happened to have u-boot on it... frans managed to create a
debian-installer for it... ohhh, that's right: there was a hardware
switch which told the S3C6410 CPU to load off of the external SD/MMC
card instead of the NAND flash. so we found a root exploit (or two),
then verbatim-copied the NAND flash partition onto an SD/MMC card,
worked out where the kernel and the initrd were and just splatted an
alternative (and debian-perfect) on top.
as this was being written onto the SD/MMC card, it didn't matter if
it was screwed up: if screw-up, remove SD/MMC card, go back to
previous version, try again.
unless the manufacturer has *actually* designed the system to be easy
to multi-boot, and has included linux and u-boot kernel source code,
respected the GPL etc. and has generally been helpful (such as the
ODroid from http://hardkernel.com, the pandaboard or the iMX53
quickstart board), or unless you find something that's been hacked or
is hackable (and in some cases, like the CT-PC89E or the Toshiba
AC-100, has been reverse-engineered), you should steer well clear.
... wow, f*** me i just looked up hardkernel.com, to find you their
instructions / wiki pages on how to build / replace kernels and
u-boot, and f*** me they've got a new product out.
http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G129705660781
wooo-hoo-hooo dang me, they've been granted access to samsung's new
1ghz dual-core cortex A9, which is available on a B2B module 45mm x
23mm with a 1gb 800mhz DDR2 RAM in POP form:
http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G129705564426
that's... a dead sexy [developer] system. 10in 1388x768 LCD
(hooraay!) and a capacitive touchscreen [which added $150 to the
price, at least. ouch].
sorry, meike - i just had to throw that in :)
anyway - here's what i did 18 months or so ago, when i was actually
using the S5PC100-based ODroid that i have:
http://dev.odroid.com/projects/debiandroid - it's a bit of a
hack-fest, but it shows you that something's at least possible, even
if you don't have a nice prepared debian-installer jobbie. since i
wrote this, you can see that someone else has hacked in some
additional instructions: apparently they used debootstrap - the key
command is this:
# debootstrap --arch=armel --foreign stable grip/
http://ftp.uk.debian.org/emdebian/grip/
which is kinda cool and i wish i'd either thought of it or known
about it oo... oodles-of-months ago, would have saved me a lot of
arseing about.
these are the kinds of lovely little tricks that you'll need to
deploy, unless it just so happens that someone has held your hand (ahh
bless 'em) and pioneered / prepped a system already. and documented
it. and, preferably, created a debian-installer initrd + kernel
specifically custom-tailored for that specific device already [all
this for reasons already stated: concept of BIOS does *not* exist in
the ARM embedded world...]
so, meike: as you work for a linux embedded company already, you're
already familiar with booting random root filesystem images: get to
it, do everyone a favour, pick a system, get it working, and the go
one step further: make a debian-installer. when you find the
instructions on how to make debian-installers for ARM systems please
do let me know cos i can't be pissed at frans for not telling me how
he did the CT-PC89E one :)
l.
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