What is iwlwifi's "lar_disable"?
I'm seeing a lot of posts reference lar_disable like this one for instance. I'm wondering what it does. modinfo iwlwifi just says,parm: lar_disable:disable LAR functionality (default: N) (bool)What is...
View ArticleWhat's the reason to add a symlink to /dev directory?
I understand that you can write custom udev rules to create a symlink in /dev directory.But what is the use of having a symlink in /dev?What is the symlink linking to?I know you can interact with...
View ArticleWhat does it take to update kernel from 3.x to 5.X on qualcomm fsm99XX small...
As of now qualcomm fsm99xx is on 3.10.84. 3.10.84 is given by qualcomm after a lot of extensive changes. we are trying to update it to 5.10 without support of qualcomm (as they don't support any more)....
View ArticleWhat's the reason to add a symlink to /dev directory with udev rules?
I understand that you can write custom udev rules to create a symlink in /dev directory.But what is the use of having a symlink in /dev?What is the symlink linking to?I know you can interact with...
View ArticleWhat exactly does the br_netfilter kernel module control?
I'm trying to get a clear understanding of what exactly the br_netfilter Linux kernel module does (I know it has something to do with networking).My simple question I'm posing here is as follows:What...
View ArticleAutomatic module signing for distribution in Linux
I'm new to writing Linux modules (drivers) and digital signatures, so please correct me if any of my understanding is incorrect.When I run make modules_install on my module, I get the following error...
View ArticleMaking cpupower changes persistent
I have been fiddling with power management and I can't find a way to make the changes I want persistent. For example, I have set the maximum cpu frequency with this command:sudo cpupower frequency-set...
View ArticleHow to make Realtek nic use r8168 driver
I've been trying (unsuccessfully) for the last few days to make my Realtek ethernet card to work. I have no problems with my wireless connection: only the ethernet connection doesn't work.I have Ubuntu...
View ArticleeBPF vs verified Linux Kernel Modules
In what way is eBPF superior to a kernel module verified on the user-side?I'm not disputing the value of verified code; both approaches would be fully statically verified.Both approaches require...
View Articleath11k_pci: failed to connect to HTT: -110
I have Qualcomm QCNFA765 wifi card.I am using custom-compiled kernel 6.1.55 and I have ath11k_pci in the kernel, and all firmware files are loaded successfully. Yet, when booting, I see on the...
View ArticleWhere are Kernel global variables stored?
I am currently writing a Linux kernel module. I am aware that in case of userspace programs, uninitialized global variables (exported to other modules using EXPORT_SYMBOL) are stored in BSS segment and...
View ArticleHow to enable weak-updates with Fedora vanilla kernels (copr)?
I enabled the Fedora vanilla kernel stable (https://fedoraproject.org/wiki/Kernel_Vanilla_Repositories) for my server.I compiled a kernel module for a specific kernel version but once it's updated, I...
View ArticleHow do make install and make modules_install affect the existing kernel...
I installed Ubuntu 23.04 from a live USB, then obtained the source for Linux 6.5.5 and built a new kernel with some settings changed (mainly for some RT kernel experiments). I did make install but am...
View ArticleHow to write a program to trigger memory direct reclaim?
Recently, my server experienced a hang which lasted for about ten minutes.Upon investigation, I discovered that the system triggered a direct memory reclaim.In my server, the value of...
View ArticleHow can I fix my USB WiFi device not being detected after boot unless I...
PreambleAfter searching the web and trying several troubleshhoting steps, I now require your help to my quite specific issue with an USB WiFi device:# lsusbBus 001 Device 005: ID 0bda:8176 Realtek...
View ArticleMake Apple Keyboard Settings persistent in ../hid_apple/parameters/
i'm running Ubuntu 16.04 LTS and want to use an apple keyboard (wired). No i'm facing some problems whith making my custom settings permanent. I'm using the 'English internationl, AltGr dead keys'...
View Article“binutils”/Kernel 6.5.X - “Invalid –compress-debug-sections option: `zstd’”
I'm trying to build a driver for a USB to HDMI adapter...Bus 001 Device 010: ID 534d:6021 MacroSilicon VGA Display AdapterNOTE:"lsusb" output.... but this error is occurring...Fatal error: Invalid...
View ArticleExplicit kernel module load at startup
I'm using grsecurity kernel which disallows automatic kernel load thus several systemd services don't work. After manually loading modules with modprobe and restarting module everything works correctly...
View ArticleHow to backport the panfrost driver on the ARM Chromebook from kernel 5.15 to...
I've almost completed my project : to virtualize FreeBSD on top of Linux with qemu-kvm on the ARM Chromebook.Everything works great. Even the network on the vm. One last task needs to be...
View ArticleHow to correctly create and stop kthreads?
I wrote the following kernel module:#include <linux/module.h>#include <linux/kernel.h>#include <linux/delay.h>#include <linux/kthread.h>#include <linux/sched.h>#include...
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