building realtime kernel & remastering for tiny core linux

[webb]

interestingly, if i build a 64-bit 3.0.21 kernel with tinycore patches and config-3.0.21-tinycore64, but set the version string to 3.0.21-w64, it does boot. if i compile with the same .config and patches but with version string 3.0.21-tinycore64, then i cannot boot, just as with official tinycore vmlinuz64. ("fixing recursive fault" error)

-webb

[Rich]

Hi webb
Another forum member  solved his  "fixing recursive fault"  error using the  maxcpus=0  boot code.

[webb]

yes but i like all of my four cores!

here's a hypothesis about this whole recursive fault business:

Code: [Select]

3.0.21-tinycore64
^^^^^^^^^^^^^^^^^ <-- 17 character version string, doesn't boot

3.0.3-tinycore64
^^^^^^^^^^^^^^^^ <-- 16 character version string, boots

3.0.21-w64
^^^^^^^^^^ <-- 10 character version string, compiled with config-3.0.21-tinycore64 but with version string changed. boots.
perhaps the kernel expects a maximum of 16 bytes in the version string.

-webb

[althalus]

yes but i like all of my four cores!

here's a hypothesis about this whole recursive fault business:

Code: [Select]

3.0.21-tinycore64
^^^^^^^^^^^^^^^^^ <-- 17 character version string, doesn't boot

3.0.3-tinycore64
^^^^^^^^^^^^^^^^ <-- 16 character version string, boots

3.0.21-w64
^^^^^^^^^^ <-- 10 character version string, compiled with config-3.0.21-tinycore64 but with version string changed. boots.
perhaps the kernel expects a maximum of 16 bytes in the version string.

-webb

Seems coincidental. The version string doesn't change just by adding maxcpus=0, but doing so lets my system boot.

Idle thought I haven't had a chance to test and/or research yet - Setting maxcpus=0 actually does two things - uses only 1 cpu, AND disables IO APIC. Maybe there's another option that can disable APIC whilst still keeping all of your CPUs, and maybe that will be enough to get around the recursive fault erro

[Rich]

Hi webb

yes but i like all of my four cores!

That may be, but one core that boots runs better than four that don't.

perhaps the kernel expects a maximum of 16 bytes in the version string.

Perhaps. Or maybe the longer string just pushes some data in the kernel into a position that causes a
seg fault.

[Rich]

Hi althalus
If you go to  http://www.mjmwired.net/kernel/Documentation/kernel-parameters.txt  you can use your browser
to search for instances of  IOAPIC  for other possible options.

[webb]

althalus wrote:
> Seems coincidental

unlikely. i compiled my own 3.0.21-tinycore64 and 3.0.21-w64 kernels, one after the other, and using the same config-3.0.21-tinycore64 kernel configuration, varying only the version string. the kernel with the 17 character version string won't boot, 16 or fewer will. i'll also try 3.0.21-tinycor64 and 3.0.21-tinycore64b, and also with a newer kernel version (e.g., 3.0.52) to see if this is a kernel bug that has been fixed.

rich wrote:
> maybe the longer string just pushes some data in the kernel into a position that causes a seg fault

sounds plausible.

-webb

[bricolodu13]

Hello,

I'm absolutly newbie but want to learn...

I've setup a basic i386 install for a squeezelite setup.
I want RT Kernel.

when I type "git clone git://gitorious.org/tinyrt/linux.git
I get the following message "-sh: git: not found" !
What am I missing ?

Thank you
Jean

[Rich]

Hi bricolodu13
You can find the RT kernel here:
http://tinycorelinux.net/4.x/x86/contrib/rt-kernel/
Or you can go to:
https://gitorious.org/tinyrt
and as it says in the first post:

click linux-->source tree and download master as tar.gz

just run ./build.sh

[bricolodu13]

Thank you Rich,

I have downloaded the  tinyrt-linux-master.tar.gz file and have copied it through ssh (WinSCP) to the TC directory.
I have also made the build.sh and two other .sh files with vi to the same directory.
I have made them usable with chmod a+x
but still, when I do ./build.sh, I got the following message :
./build-kernel.sh: .: line 15: functions.sh: not found
./build-initrd.sh: .: line 15: functions.sh: not found

Sorry to be so stupid ! 

Best regards,
Jean

[tinypoodle]

Blind guess, perhaps you would use a non compatible filesystem?

[bobowsh]

where to find the new http://distro.ibiblio.org/tinycorelinux/4.x/x86/contrib/rt-kernel/
best wishes!

[Rich]

Hi bobowsh
Welcome to the forum.

This is the real time kernel:
http://distro.ibiblio.org/tinycorelinux/4.x/x86/contrib/rt-kernel/vmlinuz.rt

You will also need the matching kernel modules:
http://distro.ibiblio.org/tinycorelinux/4.x/x86/contrib/rt-kernel/rt_modules.gz

Just a heads up, 4.x is scheduled to be removed from our server at the end
of the year.

[bobowsh]

Thanks Rich
Is there a newer version, as 15.x ?
I try to build a new rt-kernel, unfortunly faild
so i want to find this build scripts, do you have this tinyrt build scripts:

have setup a git repository at gitorious to host build scripts
https://gitorious.org/tinyrt

you can use this script to remaster latest tiny core linux images
https://gitorious.org/tinyrt/linux/blobs/master/extra/remaster-core.sh

[Rich]

Hi bobowsh
To the best of my knowledge, 4.x was the last rt-kernel we hosted.
I don't have any of the tinyrt build scripts.

I did a quick Google search for:

Code: [Select]

PREEMPT_RT patch linuxand there don't appear to be a patch for 6.1.2 or 6.6.8 which were
the two most recent kernels we released (TC14 and TC15).

For what it's worth, it looks like rt might become part of the 6.12 kernel:
https://arstechnica.com/gadgets/2024/09/real-time-linux-is-officially-part-of-the-kernel-after-decades-of-debate/