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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Cannot Use SPI frequency above 500 kHz

I am running Arch Linux ARM on a Raspberry Pi 2 Model B, and I am attempting to communicate with a TFT display. I am writing a kernel module to interface with the display using SPI, and it works, but ...
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1answer
308 views

Kernel/Firmware as Debian package

It says on the official site that "the kernel and firmware are installed as a Debian package, and so will also get updates when using [apt-get upgrade]" I run apt-get update / apt-get dist-upgrade ...
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1answer
1k views

rpi 2: Unable to change irq affinity

I am trying to optimise getting GPIO interrupts into userspace. On the single core rpi 1 I couldn't get rid of quite some timing jitter, which makes sense as there's a lot of stuff going on on the cpu....
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189 views

Custom camera driver

Is it possible to write a driver, say for a OV camera, based on the existing drivers at the RPI git repo? As is I understand, with a datasheet for a sensor it should be possible to write a similar ...
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How do I build just some in-tree modules for the Raspbian kernel?

I would like to cross-build some in-tree modules (capi, gigaset) that are included in the kernel source but not in the standard Raspbian kernel. My toolchain is using the tools from https://github....
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225 views

How can I install the latest kernel from kernel.org to Arch Linux ARM for Raspberry Pi 3 model B?

I am using Arch Linux on Raspberry Pi 3 model B. I want to install a newer kernel (currently I have 4.14.94-1-ARCH kernel installed) I have downloaded and compiled the mainline kernel 5.0-rc5, which ...
3
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1answer
394 views

How do I add an i2c device to the device tree?

I am trying to add an mpu 9250 to the device tree of my RPi 3 A+ so that my custom driver's probe function will be called. I have followed this documentation about the Raspberry Pi device tree and ...
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593 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 (...
3
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1answer
282 views

No USB with upstream kernel

I have built a kernel for Raspberry Pi 2 using the latest upstream kernel (version 4.15-rc5): https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ I configured it with ...
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103 views

Implementing a system call for CPU hotplug on RPI3/ModelB

My goal is to implement a system call in linux kernel that enables/disables a CPU core. First, I implemented a system call that disbales CPU3 in a 4-core system. The system call code is as follows: ...
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1answer
194 views

linux-imag-?-dbg and linux-headers package missing

I'd like to make use of systemtap on my 2016-02-09-raspbian/jessie system. For that I need the kernel debug package and the kernel headers. The kernel in use is: root@raspberrypi:/home/pi# uname -r ...
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running kernel 3.x on R Pi 3 Model B?

I'm looking to run kernel 3.x (3.14 to be exact) on an R Pi 3 Model B hardware. I'm trying to do this by re-compiling the kernel using the instructions here: https://www.raspberrypi.org/documentation/...
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373 views

Raspberry pi 3 stuck on bootloader

Raspberry pi 3 is stuck in boot. When i was last using it i disabled the wlan0 for some hardware hack, after that when i rebooted it it stuck on the boot as shown below. I have even tried to flash ...
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2k views

Is it possible to run the raspbian based Kano OS in QEMU?

Kano is a real, real cool device for kids. I wonder if I can run Kano OS in an emulator like qemu. I'd really like to check it out before buying it. After all Kano OS is just a Raspbian based OS ...
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3k views

TFT Kernel module not loading on startup

I'm not able to load a driver for a TFT display permanently on a Raspberry with Raspbian OS like specified here: fbtft_device name=sainsmart18 verbose=0 in /etc/modules. Whenever I restart the ...
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76 views

Boot error when attempting to install Kinect driver

I am trying to install the kernel driver to use the xbox kinect with my Rpi model B. I have followed the commands found here https://github.com/xxorde/librekinect under example for Rpi with the ...
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665 views

Specify interrupt in devicetree overlay

I have created a devicetree overlay to add an MRF24J40 transceiver to Raspberry Pi. The interface of the transceiver is SPI and an interrupt request. After some trouble the device finally appears in ...
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424 views

Using kernel debug symbols on Raspberry pi

I see that I can install packages that contain the kernel debug symbols in Ubuntu as shown here. Is it possible to do the same for Raspberry pi? I'd really like to have kernel symbols for the raspbian ...
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3k views

Best approach for real time operating system on Raspberry Pi

I need to use Raspberry Pi with a real time operating system. Of course, I want the best solution. I've searched some options, including custom kernel compilation, ready to install RTOS. So, which ...
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2k views

eGalax Touchscreen support, without kernel recompile, raspbian OS

I have been using a custom compiled raspbian OS, with eGalax touchscreen support. The problem is every time there's some upgrade or a major version change in the OS or firmware, I have to recompile ...
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95 views

new raspbian image doesn't detect usb cdc device

I have a usb cdc device that works fine in raspbian stretch. But when I change the image to new raspbian buster, my usb device isn't recognized. lsusb doesn't list my device at all! I've enabled cdc-...
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25 views

Error in configuration for I2S microphone

I follow these directions to set up the Raspberry Pi for an Adafruit I2S microphone. The line to compile the module fails with a missing script: $ make -C /lib/modules/$(uname -r )/build M=$(pwd) ...
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122 views

Facing issue in loading Ethernet Interface for Raspberry Pi 3 B+ buildroot

I am building a Custom OS using Buildroot. I am following this article to build the custom os. Author of that article gave a sample image of the os that will be created after the build is completed. ...
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19 views

Linux headers missing from a custom kernel built through cross-compilation

Helo, I have followed the instructions given at https://www.raspberrypi.org/documentation/linux/kernel/building.md to build a custom kernel. (I have cross-compiled it on an x86 box.) The custom ...
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237 views

LIRC receiver problem after kernel update

I recently updated my raspberry pi 3 using sudo apt update && sudo apt upgrade . During the process rpi kernel got updated. uname -a Linux raspberrypi 4.19.42-v7+ #1219 SMP Tue May 14 21:20:...
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105 views

How to get maximum GPIO output speed in Kernel module?

I'm writing a Linux kernel module on RPi2 to push an array to RGB Led matrix, so I want to have maximum speed of GPIO to reduce the 'flick' when it run Bit Angle Modulation. According to this site, ...
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79 views

Configure SPI from Kernel Space by writing to the SPI Registers

I'd like to write my own SPI driver to configure the SPI interface by means of writing to the CS, FIFO, and CLK SPI registers. I have disabled the SPI interface in raspi-config. I followed the ...
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71 views

Kernel error : [drm] Resetting GPU

I am using an app which is using the vc4-drivers. Sometimes videos freeze for an instant, and I see a kernel message saying : [drm] Resetting GPU After that, some font are no more displayed but the ...
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33 views

Sd card gets corrupted on some monitors?

When connected to Monitor DELL e2218hn, SD card with NOOBS installed is getting corrupted within 2-3 hours of use. This is not the case with other monitors as it works really smooth. ISSUE: When Pi ...
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66 views

iptables doesn't recognise REDIRECT as target

Trying to redirect traffic using iptables v1.6 and the following line: iptables -t nat -A PREROUTING -p udp --dport 67 -j REDIRECT --to-port 6767 which results in the following output: iptables: ...
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1answer
473 views

Raspberry Pi Zero as webcam

I read some case, like using dwc2 and g_webcam in /boot/config and cmdline. but hard to understand and doesn't work. and can't find a tutorial, there are some tutorials only about serial and ethernet. ...
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2answers
268 views

vcgencmd in buildroot

I am using buildroot to create a custom os for my raspberry pi. I would like to use the vcgencmd command, but I am unable to find the package that includes these tools. I have tried searching the ...
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63 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 ...
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88 views

Kernel panic, real time clock (possibly), UPS Pico

Have a fresh install of KivyPie, which is some months old, with updates (have done apt update/upgrade). It crashes: and the reason seems to be these two lines enable_uart=1 dtoverlay=i2c-rtc,ds1307 ...
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165 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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256 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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300 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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1answer
613 views

Problems with compiling drivers for rtl8192cu

I'm trying to use realtek 8188cu module in concurrent mode(both station and AP mode simultaneously). I downloaded the driver source files from here: https://github.com/raspberrypi/linux/tree/...
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1answer
292 views

Kernel Development with Raspberry Pi

I want to start working and playing with linux kernel. Instead of trying on my own system, I want to do the same on raspberry pi. I want to compile my own kernel and start working on my first kernel ...
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0answers
201 views

What kernel file to use for piCore 9 on qemu?

Trying to load qemu with the good old "kernel-qemu" file results in a sync error. qemu-system-arm -M versatilepb -cpu arm1176 -hda piCore-9.0.3.img -kernel kernel-qemu -m 256 -append "root=/dev/sda2" ...
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163 views

How do you add new “driver.c” files to get built with kernel

I've been following this guide to it's entirety when building existing kernel modules with no issues. My problem arises when I try to add my own driver.c files to the /linux/drivers/input/touchscreen ...
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3k views

How to achieve better Jitter for LinuxCNC on Raspberry PI?

Question Is it possible to achieve reasonable real-time with RaspberryPi (ideally jitter < 50us, or in the worse case 150us ) If yes, how to achieve those values, targeting LinuxCNC? After all ...
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600 views

Raspberry Kernel Parameters

I'm working on the /boot/cmdline.txt, and found the parameters : vt.cur_default=1 vt.global_cursor_default=0. Where I can get the full documentation about vt? does it have other parameters? Thank all!
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1answer
382 views

Stuck on Rainbow Screen after kernel upgrade on CentOS7

I ran 'yum update' on my Raspberry Pi3 running Centos7, and now it will not boot. Both LED's are solid (no flashing) and it does not get past the 'Rainbow Screen'. The following packages were ...
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2k views

Installing Cam on Pi

I have just bought me Raspeberry Pi Camera and want to install Video4Linux on my Pi. I have updated my Pi with the latest SW, and I have extended gpu_mem to 128 on my Pi. I am ready to go...... I ...
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0answers
476 views

Custom Linux kernel Ubuntu Mate (Raspberry Pi)

I'm using Ubuntu Mate for my Raspberry Pi 2 and I'm trying to add a few modules such as enable AppArmor and few other seccomp configurations needed for lxc such as: CONFIG_SECCOMP_FILTER, ...
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299 views

Raspberry Pi 2 SoC support in Linux 4.5

Today Linux Kernel 4.5 was released with support for Broadcom BCM2836 (Raspberry Pi 2 SoC) (sic). What does it mean exactly, given Raspberry Pi 2 is already working under linux?
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281 views

Error is raised when I compile simple driver module on Pi itself with a corss-compiled Kernel

I cross-compiled a new Kernel(3.18.10) on Debian Jessie amd64 for RPi2. Later, when I compile a simple Hello-World module with this kernel, however, an error is raised: make -C /lib/modules/3.18.10-...
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872 views

Invalid module format error on Raspberry. Kernel 3.10.25+

I am trying to install a module on my Raspberry Pi B+ running with Raspbian. To know the version of the Kernel I run the command uname -a and i got this: Linux raspberrypi 3.10.25+ #622 PREEMPT Fri ...
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944 views

USB Issues with recent kernel build

I am trying to roll my own image for the raspberry Pi, I am using a B+ model Pi. What I want to do is build my own kernel and for now have it load busybox or something similar, but I seem to be ...