[Arm-dev] Community kernel 4.18.x

[Pablo Sebastián Greco]

El 21/10/18 a las 17:06, Mark Verlinde escribió:
> -----Oorspronkelijk bericht-----
>> Afzender:Mark Verlinde <mark at havak.nl>
>> Verstuurd: Woensdag 17 Oktober 2018 18:49
>> Aan: Conversations around CentOS on ARM hardware <arm-dev at centos.org>
>> Onderwerp: Re: [Arm-dev] Community kernel 4.18.x
>>
>>
>> -----Oorspronkelijk bericht-----
>>> Afzender:Pablo Sebastián Greco <pablo at fliagreco.com.ar>
>>> Verstuurd: Woensdag 17 Oktober 2018 18:09
>>> Aan: Conversations around CentOS on ARM hardware <arm-dev at centos.org>
>>> Onderwerp: Re: [Arm-dev] Community kernel 4.18.x
>>>
>>>
>>>
>>> El 17/10/18 a las 11:47, Mark Verlinde escribió:
>>>> Hi,
>>>>
>>>> Kernel 4.18.x brings nice features, CPUFreq for Allwinner H3 SOC's being among them.
>>>>
>>>> Therefore I had a go on updating to the community-kernel-latest version 4.18.14-200.el7 which failed;
>>>> Dracut could not (re)build a intitramfs-4.18.14-.. and (probably because of this) uInitrd-4.18.14-.. was missing to.
>>>> Unfortunately did not write the exact error message down; next time will do so.
>>> Does /boot have enough space?, I usually try to have 3 kernels at most.
>>> I've been using that kernel in 3 different SoCs without problems,
>>> including Bananapi M3 (same SoC as the cubieboard5)
>> I do not doubt it had because it was the second kernel update done (i.e would be the 3rd installed)
>>
>> However : just successfully installed  with a more conservative approach 4.17.17 > 4.18.9 > 4.18.14
>> Side note is: this is on a home brew image without RPI bits and peaces, 786MB boot partition with ext4 file-system.
>> In time I will try again with default Centos-Generic image.
>>
>> i'm happy now:)
>> cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
>> ondemand
>>
>>>> BTW: Update to Kernel 4.17.17-200.el7 was successful on my oragngepi-plus2e
>>>>
>>>> In my own interest i'd really want to help to debug this;
>>>> but to be able to do this i need to understand in more detail how we boot Centos on our u-boot based SBC's.
>>>> I got the broad picture: u-boot >> extlinux bootloader >> kernel >>
>>> Correct
>>>> Getting lost however looking at extlinux/extlinux.conf , grub/grub.conf and not knowing the content of boot.scr
>>> You can ignore grub.conf and boot.scr, extlinux.conf is all you need
>> Sorry to persist, I'd really like to understand in more detail;
>> Questions circling in my head (among others)  are:
>> Why do we have a uInitrd _and_ initramfs ?
>> Why do we have a uimage _and_ vmlinux ?
>> Why does my odroid HC1 boot with a Fedora image but not with Centos (kernel 4.14.71 nor 4.17.17)? (despite specific USB3 patches are backported to 4.14)
>>
>>>> Can somebody enlighten me on this, or show me some further reading.
>>>>
>>>> (I did search fedora's arm documentation without getting smarter..)
>>>>
>>>> Actually in response to "Cubieboard5 performance"
>>>> (https://lists.centos.org/pipermail/arm-dev/2018-October/003515.html)
>>>>
>>>>
> Just a heads up, update to 4.18.16 works flawless on the above described setup on a oragngepi-plus2e.
> Did not find the time to test it with a default img as I'm still in a fight with the odroid HC1.
> For the latter the good new is: it's not an issue with the kernel but with the initramfs.
>
Thanks for testing!!
WRT the odroid, do you have an error log?
I've had my share of boot problems with supported devices, and they end 
up being solved by something like what I said in this mail 
https://lists.centos.org/pipermail/arm-dev/2018-August/003399.html.


Pablo.