Re: [yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hello all, in case it helps someone else I found the dependency that was avoiding the RT patch to be applied to raspberrypi4-64 build. In bcm2711_defconfig for arm64 KVM is enabled. If KVM is disabled then the patch is applied. So in .cfg file you can add: CONFIG_KVM=n -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59351): https://lists.yoctoproject.org/g/yocto/message/59351 Mute This Topic: https://lists.yoctoproject.org/mt/96470693/21656 Mute #raspberrypi:https://lists.yoctoproject.org/g/yocto/mutehashtag/raspberrypi Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hi Joel, thanks for creating the issue. Does the solution from Aleksandr work for you with raspberrypi4-64? The funny thing is for me it doesn't. As I mentioned above if I use his solution: for MACHINE = "raspberrypi4-64" in local.conf, the .config file has following configs: CONFIG_HAVE_PREEMPT_LAZY=y CONFIG_PREEMPT_NONE=y # CONFIG_PREEMPT_VOLUNTARY is not set # CONFIG_PREEMPT is not set If in the local.conf I replace the machine to MACHINE = "raspberrypi4" and I bitbake again, the .config file looks as follow: CONFIG_HAVE_PREEMPT_LAZY=y CONFIG_PREEMPT_LAZY=y # CONFIG_PREEMPT_NONE is not set # CONFIG_PREEMPT_VOLUNTARY is not set # CONFIG_PREEMPT is not set CONFIG_PREEMPT_RT=y CONFIG_PREEMPT_COUNT=y CONFIG_PREEMPTION=y Meaning when the machine is set to raspberrypi4-64 and CONFIG_PREEMPT_RT is requested via the .cfg file in the file .config in work directory CONFIG_PREEMPT_NONE=y is getting set. Whereas with Machine raspberrypi4 it works as expected. -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59178): https://lists.yoctoproject.org/g/yocto/message/59178 Mute This Topic: https://lists.yoctoproject.org/mt/96470693/21656 Mute #raspberrypi:https://lists.yoctoproject.org/g/yocto/mutehashtag/raspberrypi Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hello Joel, I do get the same, but my understanding is that the RT features are not enabled. I would expect to get: Linux raspberrypi4-64 5.15.34-v8 #1 SMP PREEMPT *RT* Tue Apr 19 19:21:26 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux When I check the .config file in the work folder CONFIG_PREEMPT=y is set but I would expect to see CONFIG_PREEMPT_RT=y instead. That is what you get for rpi4 32 bit as mentioned by Aleksandr above. Is my understanding wrong? -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59154): https://lists.yoctoproject.org/g/yocto/message/59154 Mute This Topic: https://lists.yoctoproject.org/mt/96470693/21656 Mute #raspberrypi:https://lists.yoctoproject.org/g/yocto/mutehashtag/raspberrypi Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hello Joel,
thanks for your reply. I was not aware about this possibility. I have tried it
and the preemptive rt kernel is built instead of standard
("linux-raspberrypi4_64-preempt-rt-build" is available in
build/work/linux-raspberrypi/...) but still the configuration file does not set
the CONFIG_PREEMPT_RT=y for raspberrypi4-64, even if a .cfg is added using a
.bbappend file. So in the end the RT option is not enabled.
Any idea why it works for raspberrypi4 but not for raspberrypi4-64?
Best Regards,
Carles
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Re: [yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hello Lukasz, Aleksandr, I have not managed to build it for Rpi4-64. I followed the same approach as Aleksandr but it does not work for 64bit system. Doing exactly the same changes as Aleksandr if I build for MACHINE = "raspberrypi4-64" in local.conf, the .config file has following configs: CONFIG_HAVE_PREEMPT_LAZY=y CONFIG_PREEMPT_NONE=y # CONFIG_PREEMPT_VOLUNTARY is not set # CONFIG_PREEMPT is not set If in the local.conf I replace the machine to MACHINE = "raspberrypi4" and I bitbake again, the .config file looks as follow: CONFIG_HAVE_PREEMPT_LAZY=y CONFIG_PREEMPT_LAZY=y # CONFIG_PREEMPT_NONE is not set # CONFIG_PREEMPT_VOLUNTARY is not set # CONFIG_PREEMPT is not set CONFIG_PREEMPT_RT=y CONFIG_PREEMPT_COUNT=y CONFIG_PREEMPTION=y So for raspberrypi4 the RT kernel is built whereas for raspberrypi4-64 a non preemptive kernel is built (without adding rt.cfg or the patch a PREEMPTIVE kernel will be built, i.e. CONFIG_PREEMPT=y is set in the .config file). Once I figure out why this happens I will post it here. Any further hints are appreciated. Best Regards, Carles -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59124): https://lists.yoctoproject.org/g/yocto/message/59124 Mute This Topic: https://lists.yoctoproject.org/mt/96470693/21656 Mute #raspberrypi:https://lists.yoctoproject.org/g/yocto/mutehashtag/raspberrypi Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
[yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hello all, I am trying to use the preempt-rt patches while building my image for raspberrypi4-64 using Yocto and meta-raspberrypi. I could see that in older branches like warrior there was a specific -rt recipe accessing the specific -rt branch e.g. "rpi-4.19.y-rt". I do see in the linux/raspberrypi git that for newer branches like "rpi-5.15.y" there is no rt specific branch anymore. However from just checking through the mailing list and commits I was not able to understand what the history is, and if support was stopped or there is now another way to do this. Is it still possible to get the preempt-rt patches to build the kernel within meta-raspberrypi using "PREFERRED_PROVIDER_virtual/kernel in local.conf? Any hints on how to accomplish this with the latest releases (if still supported) would be much appreciated. Best Regards, Carles -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59059): https://lists.yoctoproject.org/g/yocto/message/59059 Mute This Topic: https://lists.yoctoproject.org/mt/96521676/21656 Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases?
Hi Alex, Andrei, thanks for your reply. Based on your feedback I've tried the following: - I have downloaded the patch patch-5.15.86-rt56.patch from https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.15/ and stored in ./meta-raspberrypi/recipes-kernel/linux/files - I have created a file linux-raspberrypi_%.bbappend in ./meta-raspberrypi/recipes-kernel/linux - I have created a .cfg file with CONFIG_PREEMPT_RT_FULL = y in ./meta-raspberrypi/recipes-kernel/linux/files - I have added both patch and cfg file in bbappend using SRC_URI:append:rpi. I can observe the following: - patch and cfg files are available in ./build/tmp/work/raspberrypi4_64-agl-linux/linux-raspberrypi/1_5.15.34+gitAUTOINC+e1b976ee4f_0086da6acd-r0 - new folder linux-raspberrypi4_64-preempt-rt-build is available inside the folder above. But the problem seems to be that CONFIG_PREEMPT_RT = y is not applied to the .config file. So it seems the preempt-rt kernel is built but without the full preempt-rt support. - When I do bitbake linux-raspberrypi -c menuconfig I cannot select the full real time preempt kernel, only preemptible option available is --> Preemptible Kernel (Low-Latency Desktop). Fully Preemptible Kernel (Real-Time) is not available. - When I flash the image in the Rpi4 and run uname -r I see that the rt kernel has been built --> 5.15.34.rt56.v8 - but only with PREEMPT option but without RT when I do uname -v --> #1 SMP PREEMPT Tue Aug 9 21:20:00 UTC 2022 (without RT). I have tried building linux-yocto-rt for qemu and there I see that CONFIG_PREEMP_RT = y is available in the .config file. Also if I open menuconfig I have the option to select in General setup --> Preemption Model --> Fully Preemptible Kernel (Real-Time) If you can provide any hints on what am I missing it would be highly appreciated. Best Regards, Carles -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59057): https://lists.yoctoproject.org/g/yocto/message/59057 Mute This Topic: https://lists.yoctoproject.org/mt/96470693/21656 Mute #raspberrypi:https://lists.yoctoproject.org/g/yocto/mutehashtag/raspberrypi Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
[yocto] [meta-raspberrypi] Is Preempt-rt still supported in master / latest releases? #raspberrypi
Hello all, I would like to understand if it is still possible to build an image for raspberrypi4-64 where the preempt-rt patch is applied to the kernel, e.g. by adding " PREFERRED_PROVIDER_virtual/kernel" to local.conf. I could see that in older branches of [meta-raspberrypi] there was a specific recipe for the preempt-rt patch, e.g. linux-raspberrypi-rt_4.19.bb ( https://github.com/agherzan/meta-raspberrypi/blob/warrior/recipes-kernel/linux/linux-raspberrypi-rt_4.19.bb ). This recipe was using the specific raspberrypi branch rpi-4.19.y-rt. I see that in newer branches this rt branch disappeared but I was not able to understand the history and what is the current method to implement this patch, assuming is still supported. Any hints on how to do this would be much appreciated. Best Regards, Carles -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#59028): https://lists.yoctoproject.org/g/yocto/message/59028 Mute This Topic: https://lists.yoctoproject.org/mt/96470693/21656 Mute #raspberrypi:https://lists.yoctoproject.org/g/yocto/mutehashtag/raspberrypi Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
