Tiny Computer with Printer port

Post and links withdrawn - superseded by impending post

Hi John

I get a BusyBox ... and a prompt (imitramgs) if I try

I presume you are trying to install 8.04, seems the best choice.
The initramfs image from 2.6.24 doesn't work properly with the box without the BIOS changes, it can't resolve the root device, either as a UUID or a /dev/sda1 notation.

There are two possible solutions for you, both require the same start.

Boot the box and immediately press and hold the [delete] key, you will enter BIOS setup

Make the changes as per section 3) of my 8.04 instructions

If you have the original CF card installation still intact you can upgrade that
Re-boot and hold down the [Escape] key to get into the GRUB menu.
(you need to have a PS2 plugged keyboard or a USB one with a PS2 adaptor because USB is not recognised at that stage)
When in the GRUB menu, select the rtai kernel, which should now boot.
After that you can follow load the tarballs and follow the instructions

If you just have your USB stick, that should likewise now boot (so long as you remove the CF card or change the boot order in BIOS)
and you can continue from there.

regards

I did the bios changes before trying to install the 8.04 LiveCD

You had me doubting myself, so I went back into BIOS and reverted the settings to original.

That does not boot 2.6.24-16-rtai and drops into busybox shell
Changed IDE Operate Mode to Native Mode and still did not boot
Change Standard IDE Compatible to Enabled and it booted

Typically I had made 2 changes at once when I originally tested it, looks like only the second was needed, but just in case it needs the combination of the 2, do both.

Its a long time since I immersed myself in the minutiae of the linux boot sequence.
What I imagine is happening is, that with the default IDE settings, that kernel cannot probe IDE and discover what devices are available in order to build the devices in /dev
Then when it hits the root=xxx location, it cannot find the specified drive.

The error you get is something like 'device xxxxxxxxxxxx does not exist in /dev/disk/by-uuid/' which fits.

If you have the original CF card installation still intact you can upgrade that

I may have given you a duff steer there, seem to recall that whilst it had the 2.6.24-16-rtai kernel on it, it did not in fact have the realtime files or emc2.
You could put them on, but would probably be easier to do an install from the Live CD to CF card, by whatever method and start from there.

regards

Hi

Today received the .configs and patches used by Anthony's engineer to build the 2.6.32-vortex86-sg-rtai kernel for the NCBOX, enabling Ubuntu 10.04 to run Linuxcnc.
Hoped they might be able to be tweaked to improve latency

The kernel patch for vortex is pretty much about updating the PCI IDs so that the chips are recognised and nothing to be done with that.

The kernel .config was very similar to the one I made myself in testing, no SMP, 486 instruction set used.
The only extra thing I did was to disable all the power management functions.

I rebuilt the kernel, realtime and a RIP of emc2-2.5~pre to test.

The results were quite disappointingly similar, indeed worse regards the servo thread.
base thread max jitter about 8% better at 27657 servo thread - awful at 344466

This all just goes to evidence that the NCBOX runs far better (very well actually) with the earlier 2.6.24 kernel on Ubuntu 8.04,
probably irrespective of whether you are using a stepper based machine or not.

regards

Hi

After another week spent compiling kernels and testing resultant re-builds, I have consolidated everything that resulted into one download page
(location subject to change - see below)

The 10.04 install, with the new vortex kernel, does run Linuxcnc, but the latency figures are so poor, especially on servo thread that I have discounted it.
It is the old problem of newer kernels on old type processors, just not running well, even if built as non SMP etc

Accordingly I have posted 2 methods of upgrading the Live CD install of 8.04 with EMC2 2.3

The first replaces the kernel with a 2.6.30-vortex86mx-rtai kernel image I built, which has proper working network
This enables all the other files needed to upgrade, to be downloaded as sources and built.
It builds a RIP install of Linuxcnc 2.5, so that you can still dual boot kernels and use the original install version.

The second uses zips of packages to carry out the upgrade sequence required to change EMC2 2.3 to Linuxcnc 2.5 on a machine without networking
This may be of use to those wishing to do the same on an ordinary computer, in a shop with no network

There is nothing to prevent you doing both procedures and running Linuxcnc 2.5 on both dual booting kernels - that is what I have done

It can all be found at myweb.tiscali.co.uk/drahthaar/CNC / for now

Both kernels will run at between 10 -15K heavily loaded on Base thread and 10 - 50K on servo (the newer kernel is higher than the stock 2.6.24 one)

Both are perfectly usable for software stepper and external card setups, so now I really am going to stop fiddling with kernels etc and actually trial the NCBOX in the workshop!

regards