Today I noticed that after I first booted my computer, my motherboard’s Bluetooth card wasn’t detected. I need bluetooth to use my speakers because my soundcard doesn’t have linux drivers(another problem for another day) so I went without sound today. But then when I restarted the computer to see if that would change anything regarding the Bluetooth, it,
a.) Didn’t change anything about the Bluetooth driver, and B) now my 2.4g dongle doesn’t work for me to connect my mouse(I can still use it wired though) and my wired keyboard doesn’t work.
Both times I booted my noticed that systemd was shutting down udevd, which I have never noticed before. I know that udev is controls peripherals, so that is the most likely issue.
How would I go about fixing my computer?
Computer is running fedora 40 and has an MSI mpg B650 gaming edge wifi. I can send a hardware probe if necessary
Indeed, gaps are present in my knowledge. I understand what you wrote, in theory, but vaguely based on my reading from a forum on kernel architectures several years ago. I’m most familiar with the user experience of configuring a custom Linux kernel with Gentoo versus needing a WiFi driver that I need WiFi access to source.
Since you are touching on a gap in my knowledge, perhaps a more recent issue and curiosity will help me ground this a little better if you do not mind responding. What is the deal with secure boot and Windows drivers? How are they able to run some random driver from the internet that has DMA?
Secureboot and DMA are two different and AFAIK unrelated things. Secureboot primarily exists to ensure that only trusted OS kernels are run on a particular device. Otherwise someone could just boot their own OS installation from wherever and then have it access your storage and other devices and thus compromise your machine. I am not entirely sure how it works but I think it uses cryptographic signatures for kernels and drivers that aren’t built into a kernel. I know that on Linux with Secureboot on if you want to use certain dynamically loaded drivers then they have to be signed. I prefer not to deal with all that so I just disable it in the firmware because no cyber criminal has physical access to my PC anyway.
DMA is just a way to get data from peripherals without CPU intervention. Without DMA every time a peripheral wanted to send your machine data it would have to trigger an interrupt (or be polled continuously) which the OS would catch and then read the data from the device. This isn’t really super practical with modern hardware hence DMA allows peripheral devices to write directly to the system’s main memory without the CPU (or the OS that runs on it) being involved at all. Then the kernel can read that data from memory whenever it sees fit to do so.