Questions tagged [kernel]

The kernel is the central component of the operating system and manages hardware, process scheduling, file systems, virtual memory paging, inter-process and network communication, etc.

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“Panic:VFS: Unable to mount root fs on unknown-block(179,2)” [duplicate]

When booting my Pi, I get an error that states: "Panic:VFS: Unable to mount root fs on unknown-block(179,2). It's rather annoying, and I've tried lots of various things, I've googled and searched, but ...
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1answer
321 views

Kernel panic on shutdown/restart when relay board connected

I have a 3B+ with an added relay board. It's running Rasbian Stretch Lite (Linux blinky-stockholm 4.14.69-v7+ #1141 SMP Mon Sep 10 15:26:29 BST 2018 armv7l GNU/Linux) It seems like, if the relay-...
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5answers
17k views

GPIO Interrupt debounce

I was following this guide, Raspberry Pi GPIO interrupts in kernel space, to create a kernel module handling GPIO interrupt. The problem is that this code doesn't have software debounce implemented. ...
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3answers
234 views

RPi 3 kernel without VFAT support

I am building a very compact Linux kernel for my RPi 3. I have stripped a lot of features from the kernel. The current kernel size is around 4 MB. Currently I only have ext4 and vfat FS enabled. I ...
3
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0answers
1k views

Why doesn't extract-vmlinux work with Raspbian's /boot/kernel*.img?

To monitor if a reboot is necessary, I wanted to compare the version of /boot/kernel*img against the version of the running kernel. To get the kernel version of a compressed linux kernel image (...
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0answers
147 views

How do I interface with the “cprman” clock manager from another kernel module?

It's relatively simple to control the clock manager registers. I've found a set of values, and have C code that writes the desired values to the clock manager registers. This works well; that part ...
3
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1answer
118 views

Execution interruption while holding a kernel spin lock

I want to toggle an GPIO pin with a certain accuracy. (i.e. latency about 1 us). I have a Raspberry Pi 3 model. Therefore I wrote a simple test kernel module. The toggling loop does basically this: ...
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0answers
372 views

Kernel module can't be loaded - “invalid module format”

Headline: I've cross-compiled a kernel module for the Raspberry Pi, but on attempting to load it, I get the following error: insmod: ERROR: could not insert module testmod.ko: Invalid module format ...
3
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1answer
8k views

What repository to add for apt to find raspberrypi-kernel?

In the default Raspbian image I find *raspberrypi* kernel, bootloader, firmware etc. Using a bootstraped Installation I don't find them but using the same entries in /etc/apt/sources.list. In ...
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3answers
28k views

Kernel panic, unable to mount root fs on unknown-block after restart

My Raspberry Pi has been hosting a small site from home for a few days, and everything was working fine. It's completely headless, so I use SSH for everything. This morning however when I woke up, I ...
4
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2answers
982 views

Low Energy Consumption Kernel

I am thinking about compiling the kernel in order to have a low consumption configuration ready for the raspberry. Is there any configuration or .config created before compiling it with the power ...
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1answer
975 views

Missing cpu.cfs_period_us cgroup subsystem in Raspbian Stretch on Raspberry Pi Zero

I'm dabbling about with cgroups on my Raspberry Pi Zero using the latest version of Raspbian Stretch and I was surprised to see only the following cpu cgroup subsystems available: cgroup....
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2answers
731 views

What's wrong with my DMA controller code?

So I've been stuck at the same code for a whole month now, and I'm wondering what's wrong with it. I'm trying to copy uint32_t from userland. It does not seem to work, I get value of zero and not ...
1
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1answer
938 views

Cross Compiling ARM Kernel on 64bit machine

I've been trying to cross compile a kernel for my Pi 1 on my 64bit Desktop, following this guide: https://www.raspberrypi.org/documentation/linux/kernel/building.md At this command (in the last ...
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0answers
2k views

Kernel panic - SMP: failed to stop secondary CPUs

I installed Raspbian 9 Stretch on my Raspberry Pi 2B board, I followed instructions at link https://robpol86.com/raspberry_pi_luks.html and randomly I get kernel panic message that ends: CPU2: ...
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1answer
40 views

wifi - WiFi sometimes does not work

When I powered the Raspberry Pi 3B on (I use Gentoo), WiFi was working. After reboot, it stopped working, both ip link list and ifconfig commands do not list it (they do if WiFi is working). I am ...
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2answers
6k views

Continuesly monitor GPIO input change/events in Bash

On a Raspberry Pi you can set the GPIO pins as an output or an input. An output or an input can be either high or low. For example, to monitor the input state (high or low) of GPIO pin 26 you can ...
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1answer
7k views

kernel panic not syncing: VFS unknown-block 179,6 after cloning SD

I have set up my Raspbian and need to clone the SD Card to about 20 other Raspberry Pis now. I used the following command (on OS X) to clone the SD Card: sudo dd if=/dev/rdisk3 of=~/Desktop/pi.img ...
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0answers
247 views

ftrace + addr2line

I want to get kernel source code file name and line number of a kernel function from the function address that ftrace outputted on Raspberry Pi 3. I tried addr2line -e /boot/kernel8.img [function ...
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1answer
59 views

latest raspbian kernel update broke bash

I just updated by raspbian box (stretch, upgraded raspbian-kernel, using it as console only) and somehow broke bash. Every time I try to log in (either by ssh or locally) I get the following error: ...
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5answers
20k views

Cannot Emulate Raspberry Pi using Qemu: Kernel Panic

I am trying to follow various guides on the Internet in order to emulate Raspberry Pi on my Fedora 22 machine. I have found this question: Emulating raspbian with QEMU and used it to find kernel-qemu ...
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0answers
376 views

pyusb: scanner insufficient permissions

UPDATE: I added a symbolic link to my .rules file and it is being created every time I unplug/plug the scanner. I believe my issue is more of a permissions issue with my Python code and more ...
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0answers
375 views

How do I build a custom RPi kernel DEB package?

I've got a couple of patches to the kernel that I want to apply and use in Raspbian. If I follow the Kernel building guide, I can apply the patch and get my kernel image and modules working just fine -...
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2answers
779 views

How to replace a kernel on the raspberry pi to duplicate systems on sd cards?

I have a fully working system which is on one of my SD-cards(#1). I would like to copy everything to another sd card(#2). There are a few problems here: 1) I don't know which version of NOOB or ...
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3answers
1k views

errors during booting process

I just bought a Raspberry Pi 3 Model B with NOOBS microSD Card. I only connected the USB cable for power and the HDMI cable, it keeps rebooting with these errors, like it is stuck in a loop. /init: ...
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2answers
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What is the right value of GPIO_BASE in Linux kernel for Pi?

According to "BCM2835 ARM Peripherals" page 90, the GPIO registers start from 0x 7E20 0000. While according to kernel file: arch/arm/mach-bcm2708/include/mach/platform.h, as below. #define ...
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1answer
6k views

boot hang on random: crng init dome

I have kernel 4.9.80 (arm64) installed on a Debian stable system. This is on a RPI 3b. When the kernel gets to the line random: crng init done, it stops and never continues. I have read other articles ...
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0answers
54 views

Kernel Panic : VFS :Unable to mount root fs on unknown-block [duplicate]

I was having an issue with my Pi, and ended up having to refresh my SD card with a new copy of Raspbian. I followed the links and instructions on the Raspberry Pi site about cleaning the SD card. I ...
1
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1answer
1k views

Header files not being found (sys/stat.h)

I am trying to compile a device driver to control some LEDs connected via GPIO pins. First, I got errors that /lib/modules/4.14.31-v7+/build was not found, so I ran sudo apt-get install raspberrypi-...
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2answers
1k views

Raspbian - Real Time Kernel does not boot

I am trying to make a Raspbian kernel to support real time. To do that I cloned the latest kernel from raspbian github repository and applied the Real Time patch for 3.10.25-rt23 (https://www.kernel....
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1answer
231 views

Raspbian Kernel Cross Compiling Peripherals not working

I am having trouble compiling the Raspbian kernel from source. I used the instructions here: https://www.raspberrypi.org/documentation/linux/kernel/building.md. I am cross compiling on Ubuntu 16.04 ...
7
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1answer
21k views

End Kernel panic - not syncing: Attempted to kill init

I have a problem when starting my Raspberry Pi (Rasberry Pi 3 Model B). Everything worked fine. After the last reboot I've got this error. Any help would be appreciated.
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3answers
25k views

How to build custom OS for Raspberry pi from scratch?

I am new to kernel and embedded Linux. I have recently bought a Raspberry Pi and booted it using the Raspbian. I was fascinated by the Pi, to learn more on Embedded I have decided to make an home ...
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2answers
240 views

Cron and atd jobs cant see manually mounted file systems (mounted while on ssh) [closed]

I recently upgraded to debian [/raspbian] buster. Ever since then, cron jobs creating directories using mkdir -p <directory name> will create the directory on the root file system / device ...
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1answer
1k views

Trying to apply real time patch to kernel 4.9.76

Raspberry Pi 3 model B OS: Raspbian 9.3 stretch Kernel: armv7l Linux 4.9.76-v7+ CPU: ARMv7 rev 4 (v7l) @ 1.2GHz RAM: 1GB I'm trying to apply the real-time patch (it's highly desirable for my ...
14
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4answers
22k views

Where is the kernel source for Raspbian's default 3.1.9+ kernel?

The default kernel version of Raspbian is 3.1.9+. When I try to compile an extra kernel module I have lots of error messages since the kernel header files are missing. I've checked the Raspbian ...
1
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1answer
5k views

Loading kernel module *qmi_wwan* before *option* to get /dev/cdc-wdm0 automatically

I try to setup a USB modem (Chip is a SimTech SIM5215) using QMI. Everything works fine and it connects to my mobile provider. One problem remains: most of the time the kernel loads the module option (...
0
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1answer
427 views

SVID2USB23 on RPi 3

I have recently purchased a Startech SVID2USB23 and want to use it with my RPi 3. However, linux apparently does not support this device. I found that this could be patched on previous versions of the ...
1
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1answer
655 views

Kernel panic when running Raspberry Pi 3 version of CentOS

I'm new to Raspberry Pi and Linux. I'm a university student and I'm a little stuck. I had the idea that if I formatted the SD card that come with the Raspberry Pi and put CentOS (that's the OS we use ...
1
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1answer
381 views

Raspbian on RPi2 random total freeze since upgrade to stretch

I purchased a Raspberry PI 2 two years ago and installed Raspbian Jessie at the time. I configured several services including nginx/ssh/... with very specific settings so complete OS re-install is ...
2
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1answer
1k views

Systemwide Hotkey that runs a script

I know its possible to assign a Hotkey to run a Python script by configuring the openbox/lxde-pi-rc.xml. However this Hotkey then only works under X11 GUI. What I would need is a hotkey that works ...
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0answers
630 views

Linux SPIDEV clock timing issue

I am using a Linux board called NanoPi Neo based on the H3 chipset. I got the spidev driver working and it appears as /dev/spidev0.0 I am trying to use a SPI module called RF24L01. However, I was not ...
4
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2answers
10k views

Default kernel preemption vs real time patch?

Is the default Raspbian shipped with the real time patch? I'm using the .config of the default Raspbian installation as a base for a custom kernel compilation. In the section: >Kernel Features ...
3
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4answers
2k views

How can you get video display using the FLIR thermal camera

I am working the Lepton FLIR thermal camera and trying to get a video stream from it using the Raspberry Pi. When I hooked it up and used the already existing code I got a red box on a black screen. ...
0
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3answers
9k views

Get the current Raspbian kernel version without installing

Is there a way to get the current version of the kernel for the Raspbian distribution, without installing it? I don't really want only the number, I really would like a procedure to get it next year.
66
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1answer
67k views

How does Raspberry Pi boot?

I have a raspberry mini computer and I am wondering how that thing does whole the boot process. I can compile my own kernel and init ramdisk with my own scripts and build my own minimal linux system ...
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0answers
1k views

Build a custom Android ROM for the Raspberry Pi? [closed]

How to create a custom Android ROM for the Raspberry Pi from scratch? It can be from any source, it does not matter (like aosp, lineage os, resurrection remix, etc), but the system apps must be ...
0
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1answer
434 views

Kernels running SCHED_FIFO and SCHED_RR scheduling policies respectively for Raspberry Pi 3

I want to create two kernels for the Raspberry Pi 3. One running all the processes with only the SCHED_FIFO policy, the second running the processes with only the SCHED_RR policy. Can somebody help ...
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2answers
1k views

Booting the raspberry pi and running a bare metal program

Background Info I am attempting to write a few bare metal programs and in theory I would eventually write a kernel. To get used to the environment, I found a tutorial that was known to work to could ...
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1answer
1k views

Modifying libcomposite module doesn't work

I'm trying to modify the libcomposite module in a way that it prints the functions of which are loaded to the log file. I'm using an Raspberry Pi Zero W with the 4.9.20+ Kernel. I updated everything ...

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