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My old man was trying to mess around with the drivers in his laptop (Lenovo Ideapad 330S-15ARR Type 81FB), and ended up doing something which resulted in the the device UUID, model and product getting delisted and set to INVALID in the UEFI. Then, on Windows, the touchpad stopped working entirely (although the keyboard did still work). Since he was planning to get a new laptop anyway, this one got handed over to me, and I decided to give it a go with Linux.
I had ISOs for about 4 distros (Arch, Mint, Endeavor and Xubuntu) on my main machine which I loaded on a Ventoy stick and plugged it into the broken laptop. Whenever I tried to boot Linux (past GRUB/systemd-boot menu), I'd be greeted with a black screen. More specifically, some distros would print the message `stuck at downloading kernel download initrd` and remain stuck there. Fortunately, Mint's "compatibility mode" (which just sets a bunch of options like noapic, nomodeset, etc) booted fine. So I tried the same for Arch and found that it wouldn't boot until I passed the `noapic` option. Now, I'm not exactly sure about what it'd mean if I always ran the system with `noapic`.
So my main question is, practically, is there any massive downside to setting this option (`noapic`) and running with it all the time?
For ease, I've installed Endeavor on this laptop for the moment, with systemd-boot. Of course, the touchpad doesn't function at all and I'm working around it by using a USB mouse. I'm looking a bit more into how I could proceed with getting this laptop's information listed on its UEFI again, and I don't expect anyone else to be familiar since this doesn't really seem like an Arch/Linux issue, but any help on this off-topic thing would also be appreciated.
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Okay, I just found that noapic has reduced the number of cores and threads on the system to 1. Welp, That's a pretty big downgrade from a 4-core system. Is there any way I can retain the cores while keeping apic disabled?
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From what I understand, APIC is responsible to provide the OS with system information. It's a chip on the mainboard. With APIC disabled, the OS won't get any system information, except for some very basic information, such as some legacy stuff and USB support. That's why you only got one core. The OS isn't able to see the details of your OS. Also, I'd like to point out, that APIC will disable a lot of things on your system and preventing stuff from running. It should be used only to get a bootable system, to work with. It's not something, you should be running regularly.
Probabilities are, that some driver or hardware is causing issues. NOAPIC disables everything, except for the most basic stuff... thus the system boots, as troublemaker is disabled.
I am using Ventoy as well and on one of my older machines, I got issues, when trying to boot, using normal mode. However, booting in Grub mode seems to work fine. I'd recommend trying that. Other than that, I am not of much help, I am afraid.
Last edited by BenjB83 (2025-01-26 08:49:10)
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Thanks for the quick reachout, Benj. So, if I'm understanding this correctly, with noapic, the system is indeed running on all cores, but on querying, it displays just one? Or does noapic also disable SMP (I read somewhere that it did, but also read that it's possible that the users are confusing it with nolsapic which does actually disable multi-core processing)?
Also, I did initially try booting with GRUB (as what I did for Mint). I don't think the bootloader's the one making any difference here. Regardless, it's a peculiar issue, so I'm looking to see if a clean install using Lenovo's recovery creator could get the problem fixed.
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Thanks for the quick reachout, Benj. So, if I'm understanding this correctly, with noapic, the system is indeed running on all cores, but on querying, it displays just one? Or does noapic also disable SMP (I read somewhere that it did, but also read that it's possible that the users are confusing it with nolsapic which does actually disable multi-core processing)?
I think it might be a bit more complex than that. APIC is what reports to the OS, what is available to use as hardware. With it disabled, only some legacy and very basic stuff works. This means, that you are probably only using one core... if the OS or the Kernel doesn't know it exists, it probably won't use it. I am not 100% sure on that. It is the system that describes hardware to the operating system to let understand what hardware is present and to properly configure it, controls hardware actions such as the dynamic speed fans, the power button behavior, system sleep states, optionally to control frequencies of CPUs and helps to identify some system capabilities.
Note, that APIC uses firmware, that can be out of date (given it is an old laptop, this is likely the case). You could try to update it... but again, I am not sure, if that will do anything... if you get the system to run with APIC, you might even get your touchpad to work (unless it is physically broken). Another thing coming to mind could be the Kernel. Mint uses an older Kernel compared to Arch. Arch does have an LTS Kernel though. However, I don't think it comes with the ISO, so you probably need to at least boot the system, to install it.
Have you tried installing Debian or openSUSE Leap? Something, that uses an older Kernel and older packages, to see if that works? It would at least maybe point into the right direction. Arch and EOS package-wise are pretty much the same. So that wouldn't be of much help, to compare.'
EDIT: There is some info about NOAPIC and NOLSAPIC here: https://access.redhat.com/solutions/58790.
Last edited by BenjB83 (2025-01-26 09:40:51)
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Do you get away w/ "maxcpus=1" instead of "noapic"?
After bootup you can then bring up the other cores by executing "echo 1 > /sys/devices/system/cpu/cpuX/online".
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