Tiny Core with Real Time Kernel?

[Arslan S.]

ok i am eager to submit rt kernel and images according to
http://forum.tinycorelinux.net/index.php?topic=8923.0

first i am going to create a project at gitorious, a build system which will output remastered tinycore, microcore images

second share the link to project

finally submit built images to be hosted by TC

as told in the link above i cannot use microcore or tinycore in built images and kernel

kernel will be named something like 2.6.33.3-l1-rt19

how about naming images ? is this fine ?
tinyrt.gz
micrort.gz

[curaga]

@Arslan

The cpio would only have the modules, not be a full remaster. This way it can be added fairly easily on many bootloaders, or included in a remaster with the many existing scripts.


There's no need to do a full remaster, and we would only host the module cpio, but if you want to do a remaster in addition, that's fine too.

edit: And of course, with a modules-only cpio, one can update TC without issue.

[Arslan S.]

where to submit custom kernel and modules, tcesubmit ?

[curaga]

PM me where I can download them, and I'll upload the bzImage and modules cpio. The module extensions should go to tcesubmit.

[Tuftec]

Hi Guys,

I would like to explore the application of TC in a small machine control application.
Have a a real time TC kernel would be a great start.

I some one already has built one of these, would you mind sharing it so that I can experiment.
I do not have much lknowledge on how to build a kernel, so if someone has build as an extension that would be great for me.

Cheers

Peter.

[roberts]

http://distro.ibiblio.org/tinycorelinux/3.x/contrib/

[Tuftec]

Thanks Robert.

[Tuftec]

Ok.
I have downloaded the bzimage.rt and the cpio stuff.
Now what do I do with them?
I gather I simply set up my boot loader to use bzimage.rt instead of bzimage but what do I do with the cpio bit?
It is a .gz file. Do I somehow istall this in the tce directory?

Peter.

[tinypoodle]

Practically speaking this may depend on capabilities of bootloader used.
Either add comma separated to 'initrd=' parameter or concatenate the additional cpio archives with those of base TC or MC.
This subject has been discussed in detail in more than one thread of this forum.

Also search wiki for "dynamic remaster", the priniciple of loading multiple initramfs's is the same 

[Tuftec]

I am still a bit lost.
I am a novice.
I am using Grub to boot.
I tried    cat bzImage.rt rt-modules.cpio.gz >tinyrt.bz
I then changed my to   kernel tinyrt.bz   but it did not boot correctly.
Got stuck trying to load extensions and report earlier something about   .....-rt19..... not found.

Clearly I am doing soething wrong.

[tinypoodle]

Clearly.

You have to concatenate the cpio of original base (e.g. tinycore.gz) with optional cpio archives.
The kernel remains untouched.

Besides from that, this is really getting off-topic in regard to the thread, as it is about loading multiple initrd's regardless of a real time kernel.

[Tuftec]

Sorry if this was a little off topic.
(I thought the topic was Tiny Core with Real Time Kernel)?
But you helped me get the RT Tiny core up and going.
So what I did was substitute in the boot menu file (for grub):
bzImage.rt replaces bzImage
tinyRT.gz replaces tinycore.gz
(tinyRT.gz was simply created by  cat tinycore.gz rt-modules.cpio.gz > tinyRT.gz)
Thanks.
 
Peter.

[Tuftec]

Ok.
So now I have the real time version of TC up and going.
I have tested with a simple program and it appears that the real time parts are working, how ever the High Resolution Timers are not working as expected. They appear not to be enabled correctly??? The resolution defaults to 3.33ms which is too course for effective real time applications.
Is there some way to change this?
I would like the HRTs to be able to be used down to about 10us if that is possible.

Peter.

[curaga]

I'm not familiar with RT, but both HPET and high res timers are enabled in that config. Perhaps it's just a config toggle somewhere in /sys or /proc/sys.

[Tuftec]

It appears that the HRT resolution is tied to the value of a jiffie which is 1/300 second (based on HZ being set to 300 in the kernel of Tiny core. At least in the RT patched version anyway).