Hi Gurus, I've been playing with CentOS 7's AltArch i386 builds with some good results on one machine, but can't get it to boot properly on another with a newer Bay Trail CPU. Previously CentOS 6 i386 worked on both, and that set a legacy I'd like to recreate... I *think* the problem is that the 7 kernel is non-PAE, and that has some peculiar knock on effect that prevents some PCI devices being seen, notably the device with the rootfs. CentOS 6 worked on both machines with the PAE kernel. Looking around, I found the following repo: https://mirrors.dotsrc.org/centos-altarch/7/kernel/i386/ This carries 4.14 (long term support) based -PAE kernels (as well as non-PAE) which look to fix my problem. However, I can't find any description of this repo or policy on how it is updated or the intended use. Or why PAE kernels aren't provided as an option in the 'normal' i386 CentOS 7 builds. If anyone could help explain this repo and the view on PAE for the AltArch i386 builds of CentOS 7, I would be really grateful as I can't find the info anywhere else! Kind Regards, Mike -- wavemobile Warning: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender immediately and delete the material from any computer. wavemobile Ltd is registered in England and Wales, Registration Number: 04780898.
On 3/4/19 3:39 PM, Mike McTernan (wavemobile) wrote:> Hi Gurus, > > I've been playing with CentOS 7's AltArch i386 builds with some good results on one machine, but can't get it to boot properly on another with a newer Bay Trail CPU. Previously CentOS 6 i386 worked on both, and that set a legacy I'd like to recreate... > > I *think* the problem is that the 7 kernel is non-PAE, and that has some peculiar knock on effect that prevents some PCI devices being seen, notably the device with the rootfs. CentOS 6 worked on both machines with the PAE kernel. > > Looking around, I found the following repo: https://mirrors.dotsrc.org/centos-altarch/7/kernel/i386/ > > This carries 4.14 (long term support) based -PAE kernels (as well as non-PAE) which look to fix my problem. However, I can't find any description of this repo or policy on how it is updated or the intended use. Or why PAE kernels aren't provided as an option in the 'normal' i386 CentOS 7 builds. > > If anyone could help explain this repo and the view on PAE for the AltArch i386 builds of CentOS 7, I would be really grateful as I can't find the info anywhere else! >That directory (kernel/ under altarch) is basically for the armhfp main kernel, but we are building also for aarch64, i386 and even x86_64. Its purpose (other than armhfp, where it is the main kernel) is mainly for IoT type hardware (think hobby boards, embedded systems, etc that need newer kernels for hardware support .. think things like this: https://www.intel.com/content/www/us/en/products/solutions/iot.html or 64 bit aarch64 bit type IoT boards, etc. You certainly CAN use them on anything you want and it will be maintained as it is the main kernel for armhfp. There is also an experimental/ repo in altarch with is the NEXT kernel for armhfp .. that one is currently 4.19.x. When we upgrade to CentOS 7.7.<DATE> (no idea when that will be, we obviously wait on Red Hat to release RHEL 7.7 and then rebuild the source code) we will be moving to the 4.19.x kernel in the kernel/ repo .. and for the experimental/ repo we will pick a newer LTS kernel from kernel.org to maintain in that repo. Both of these branches / repos are NOT designed to run Enterprise type workloads (that is why we have the main RH kernel from RHEL sources) .. but, you can do whatever you want with them .. and we will be maintaining them for major updates from kernel.org as required, especially CVEs released from kernel.org. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20190305/2eafc0a3/attachment.sig>
On 3/5/19 5:48 PM, Johnny Hughes wrote:> On 3/4/19 3:39 PM, Mike McTernan (wavemobile) wrote: > > Looking around, I found the following repo: > > https://mirrors.dotsrc.org/centos-altarch/7/kernel/i386/...> That directory (kernel/ under altarch) is basically for the armhfp main kernel, > but we are building also for aarch64, i386 and even x86_64. Its purpose > (other than armhfp, where it is the main kernel) is mainly for IoT type > hardware (think hobby boards, embedded systems, etc that need newer > kernels for hardware support .. think things like this: > > https://www.intel.com/content/www/us/en/products/solutions/iot.html > > or > > 64 bit aarch64 bit type IoT boards, etc. > > You certainly CAN use them on anything you want and it will be maintained > as it is the main kernel for armhfp.That?s excellent, and most helpful. So that brings support for newer hardware, AND provides a PAE version which works on all my hardware nicely. This might be useful to a number of people, and it was only through looking around CentOS 7 on Raspberry Pi that I happened across the kernel repo. Might it be worth linking to the repo from the AltArch/i386 page: https://wiki.centos.org/SpecialInterestGroup/AltArch/i386> Both of these branches / repos are NOT designed to run Enterprise type > workloads (that is why we have the main RH kernel from RHEL sources) ..Yep - wise words and duly noted, thank you. My application is small scale, so should be fine. Software is only as good as the testing anyway :-) Last question, if I may - Is there any specific reason why an i686 PAE kernel built from the main RHEL sources isn't in the AltArch i386 os- repo? Notably CentOS 6 provided both non-PAE and PAE 32-bit kernels, and it's that step from CentOS 6 32-bit PAE onto CentOS 7 32-bit which made me stumble, but okay now. Many Thanks again, Mike -- wavemobile Warning: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender immediately and delete the material from any computer. wavemobile Ltd is registered in England and Wales, Registration Number: 04780898.