Compile RTAI kernel 3.4-9-rtai-686 on deb.wheezy
Hi all,
I'm a new fan of linuxcnc. I'm experiment some feature and i am enthusiastic.
For now I'm trying to re-compile RTAI kernel for optimize it for atom CPU.
Someone can tell me what RTAI version do you use for the hybrid-cd debian wheezy at version of linuxcnc 2.6.3, and what kernel version do you use ?
I wanna try to use the /boot/config-3.4-9-rtai-686-pae for the base of recompiling.
I desire to become an active user in this community.
If i have success I can try to write a guide for the community ( I haven't found it for wheezy).
All suggestion are well accepted.
Thanks
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The sources etc are on Sebs github repos
github.com/SebKuzminsky?tab=repositories
primarily
github.com/SebKuzminsky/rtai
and
github.com/SebKuzminsky/linux-rtai-debian
His kernel processor type is set for CONFIG_M686. I have not previously found any advantage using the CONFIG_MATOM processor type, but by all means try it out.
It is also has CONFIG_SMP set.
The best latency increase will come from using isolcpus = 1 on the kernel boot line (assuming you have a twin core Atom)
If you have an old single core Atom, it may well run better built as a UP kernel, but you will need to ensure that the appropriate LAPIC switches are enabled or rtai will not build against it.
good luck
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github.com/ShabbyX/RTAI/tree/master/base/arch/x86/patches
Any suggestion on the right chose for stablest kernel?
The two option for CPU is Atom dual-core /quad-core
(i have attached a pdf )
Kernel must be patched with some debian-specific patch?
github.com/SebKuzminsky/linux-rtai-debian
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Here I've found the compatible kernel here
github.com/ShabbyX/RTAI/tree/master/base/arch/x86/patches
Any suggestion on the right chose for stablest kernel?
The two option for CPU is Atom dual-core /quad-core
(i have attached a pdf )
It is a 3.4.55 kernel basically, so I expect
github.com/ShabbyX/RTAI/blob/master/base...x-3.4.87-x86-4.patch
Kernel must be patched with some debian-specific patch?
github.com/SebKuzminsky/linux-rtai-debian
At this point I diverge from the way Seb built. He is doing a debian package build and I just build from sources.
All you need is the RTAI patch for the kernel and a RTAI config to build it
If you want to build with kpkg or whatever, you may have to scour his repos further or ask him what other patches were applied to the base kernel
regards
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The only important thing about the number of kernels your processor has, is that you set that number in BOTH the kernel config and the RTAI config.
The RTAI will fail to load if you have more cores than the RTAI config it was built with.
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github.com/ShabbyX/RTAI/blob/master/base...x-3.4.87-x86-4.patch
with kernel
www.kernel.org/pub/linux/kernel/v3.x/linux-3.4.87.tar.gz
I follow this iscruction
github.com/ShabbyX/RTAI/blob/master/README.INSTALL
ALL GOES RIGHT.
But at step 5:
Update your boot loader. If you are an experienced GRUB user, it is recommended to
modify the grub.cfg or menu.lst file by hand, to remove unncessary bloat from the file,
as grub2-mkconfig -o /boot/grub2/grub.cfg (or whatever you use to automatically generate it)
can cause serious pollution and in rare cases, impact RTAI performance.
Depending on your Linux distribution, one of these commands would do it for you:
# grub2-mkconfig -o /boot/grub2/grub.cfg
# grub2-mkconfig -o /boot/grub/grub.cfg
# update-grub
after rebooting grub show my new kernel .After the selection i have this issue
kernel panic - not syncing vfs unable to mount root fs on unknown-block(0 0)
Do you think is something related grub2 configuration or new kernel?
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Depending on your Linux distribution, one of these commands would do it for you:
# grub2-mkconfig -o /boot/grub2/grub.cfg
# grub2-mkconfig -o /boot/grub/grub.cfg
# update-grub
So which did you use?
kernel panic - not syncing vfs unable to mount root fs on unknown-block(0 0)
Do you think is something related grub2 configuration or new kernel?
Can you attach your /boot/grub/grub.cfg file as grub.cfg.txt so I can have a look at it.
regards
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grub-mkconfig -o /boot/grub/grub.cfgPlease Log in or Create an account to join the conversation.
I would try rebuilding the initrd.img
delete the old one and use
update-initramfs -c -k 3.4.87-RTAI
Then try a reboot
If that fails, I would build an unpatched version of the kernel, check that builds and runs OK on your machine, then incrementally bring back the changes until it fails again.
Depending exactly what kernel config you have used, you may have unintentionally knocked out something.
It can be a very frustrating process.
I have not built that kernel, but I know the RTAI builds OK, I have used that to produce some extra modules
regards
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update-initramfs -c -k 3.4.87-RTAI
The config file is "untouched".
I basically use this
https://github.com/ShabbyX/RTAI/blob/master/base/arch/x86/configs/rtai_32_defconfigIt's wrong choice?
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