Questions tagged [kernel-parameters]
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139 questions
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How to capture boot steps
I have a linux-box.
My hdd is nvme, hence boot is fast. I need to analyze each line of after grub.
Can I pass a kernel parameter to capture my boot lines?
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Can I deny the root access to the user keys in the Kernel key retention service?
I know the Linux kernel has a key retention service even though I haven't used it myself.
I'm constructing a system where anybody with root cannot check the keys in that service that were registered ...
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Additional steps for blacklisting compiled in kernel drivers
I am having a conflict with third party moxa driver mxupcie and the default linux 8250_moxa which is compiled in. I have been following this thread but still having issues.
-bash-4.2$ lspci -vvv -s8a:...
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How to fix or get rid of BadDLLP warnings (Correctable PCIe Bus Error) flooding my logs?
First off, this question is not a duplicate of Why is journalctl reporting "PCIe Bus Error" BadTLP and BadDLLP? because instead of asking what is causing this kernel warning, I directly ask ...
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Redirect console to ttyUSB0
I'm trying to redirect the console to ttyUSB0, with the idea of later disable tty1, but I'm not getting anywhere....
I've added
GRUB_CMDLINE_LINUX="console=tty1 console=ttyUSB0,19200n8r"
To ...
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Undefine CONFIG_BLK_CGROUP macro while building linux kernel image
I am wanted to build a custom kernel image in which macro CONFIG_BLK_CGROUP is not defined. After researching a little bit I found we can do such configurations in .config file.
To be more precise I ...
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Boot a kernel of debian installer with expert mode
I want to reinstall my VPS with the debian's official repository, instead of with the image provided by the VPS operator(I don't trust the VPS operator).
On original system I installed debian-...
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modprobe: FATAL: Module dm_mod not found in directory /lib/modules/6.6.16
I have built a custom kernel and given a CONFIG_LOCALVERSION of -grant-nvme during compilation. However, when I try to boot into it, no matter what I do, grub seems to look for /lib/modules/6.6.16 and ...
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Is there an official way to set kernel parameters in /boot/boot.scr in Debian?
I have installed Debian 12 on my Orange Pi Zero using a custom u-boot image. I notice that Debian has a file called /root/boot.scr which is rebuilt after apt upgrades. I had previously modified this ...
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“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 Adapter
NOTE: "lsusb" output.
... but this error is occurring...
Fatal ...
- 713
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Why can't keyboards be used in customized linux?
I am customizing a Linux system using a Linux kernel of 6.4.0. After booting, why is the keyboard not working? # 1. The disk is externally connected through a USB interface. If I enter the Linux live ...
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How to disable/enable bounce-buffers in IOMMU?
I am trying to figure out how to disable bounce buffers used in IOMMU when the hardware IOMMU is used.
To give more context, when IOMMU_DEFAULT_DMA_STRICT is set in the kernel it enables strict IOTLB ...
- 115
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Linux kernel difference between protected and reserved memory? (memmap parameter)
The Linux kernel takes a memmap parameter *) to manually designate memory regions for different use-cases.
Q: What is the difference between reserved memory (memmap=nn[KMG]$ss[KMG]) and protected ...
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Which Kernel version should I download to recompile my kernel with lock stats enabled
I'm trying to use the CLI tool perf, however it requires the CONFIG_LOCKDEP and CONFIG_LOCK_STAT enabled in the Kernel code.
I understand that to enable these flags, I need to download the source code ...
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Set affinity of a process using TASKSET or sched_setaffinity() to a processor core isolated using CPUSET
First, let me give a background of what I am trying to achieve. I know how to isolate a particular CPU using boot param (isolcpu and nohz_full; the housekeeping subsystem setup).
But as per my ...
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kernel ignores append init=/bin/bash
qemu-system-x86_64 -m 2G -accel kvm -kernel kernel6.1 -append "init=/bin/bash" -initrd myinitrd.gz
Supposed to run bash as init, but kernel still prints:
[ 1.400577] Run /init as init ...
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Disable webcam at boot time, by appending a boot parameter
I have an internal webcam on my Dell laptop. I don't see it listed with lspci, but it works.
I am using a self-compiled kernel, and here are the options I have enabled:
# zcat /proc/config.gz | grep -...
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Kernel data structure that shows which CPUs are partitioned (isolated) using tuned?
This is for Red Hat Linux 7.9, kernel 3.10.0-1160.71.1 .
I would like to know what kernel data structure can be used to show which CPUs it thinks are isolated using tuned. This means I've isolated ...
- 2,732
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get rid of rebooting messages and watchdog
Broadcast message from username@Desktop (Sun 1919-08-10 11:45:14 CST):
The system is going to reboot NOW!
[756.345947] watchdog: watchdog0: watchdog did not stop!
[756.472889] watchdog: watchdog0: ...
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Do subsequent arguments override previous from linux kernel command line, or vice versa?
This was prompted by another question elsewhere, which after digging into briefly a quick online search ("linux kernel command line override priority" and some variations) turned up ...
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pcie_bus_perf : Understanding the capping of MRRS
Quoting the linux kernel documentation for boot parameters :
pcie_bus_perf : Set device MPS to the largest allowable MPS based on
its parent bus. Also set MRRS (Max Read Request Size) to the largest
...
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How can I pass a parameter to a module that is not built-in to the kernel using GRUB2?
If I choose to have a module built-in (Y), I can choose "e" to edit the boot entries on GRUB2 and modify the kernel command line to include "module.variable=whatever" and it works ...
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How to find a kernel source code for ARM cortext-A55?
I want to know how to find a proper Linux kernel source code for using ARM cortext-A55.
I got a kernel source code from kernel.org.
But don't know how to "Config" my kernel to support ...
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Why would Linux kernel drop the isolcpus parameter?
I'm trying to pass isolcpus=1-4 to the kernel command line, Linux version 5.10.42 LTS. My boot manager is EFISTUB/efibootmgr. I'm booting OK but the parameter is simply not there when checking with
$ ...
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Where to get offline documentation/descriptions of individual sysctl kernel tunable parameters?
The NOTES section of $ man 5 sysctl.conf states: The description of individual parameters can be found in the kernel documentation.
But is there a way for me to find this kernel documentation offline? ...
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