327
votes
Accepted
What is rpikernelhack?
"rpikernelhack" is a fake package name and a directory name used as part of a hack (in the sense of a dirty but expedient solution to a problem) to work around the fact that the Raspberry Pi ...
- 6,406
53
votes
What is rpikernelhack?
It's just the directory name given by the developers who have created a Raspberry Pi specific set of patches to the Linux kernel.
It is a fix by the Raspbian developers to fix a FAT file-system ...
- 665
25
votes
Accepted
How compile a loadable kernel module without recompiling kernel
First of all, make sure you use the proper kernel headers. I assume that your kernel headers and source code are more updated than the kernel you're running.
Try to do an apt-get update && ...
- 7,116
22
votes
Accepted
conflicting dtoverlays
As it turns out several overlays can be loaded by adding multiple dtoverlay variables:
In this case:
dtoverlay=4dpi-3x
dtoverlay=w1-gpio
- 757
16
votes
Accepted
Pending kernel upgrade even after reboot my RPi4
Mixing @Dougie 's comment above and this post: https://www.raspberrypi.org/forums/viewtopic.php?t=270251&p=1639417
the v8 kernel is experimental and should not be used
needrestart is confused by ...
- 431
14
votes
Accepted
Control GPIO pins from C
sysfs has been deprecated and has been replaced with libgpiod.
https://www.beyondlogic.org/an-introduction-to-chardev-gpio-and-libgpiod-on-the-raspberry-pi/
The interactions are with /dev/gpiochipx ...
- 70.5k
13
votes
Accepted
failed to start udev kernel device manager
It might be interesting to know which version you are running, and if you happened to update packages recently.
I encountered a similar error message on my raspberry pi2 after upgrading to raspbian ...
- 146
13
votes
kernel types in Raspbian 10 - Buster
kernel.img is 32-bit for BCM2835 (RPi1 & Zero)
kernel7.img is 32-bit for BCM2836 (RPi2) and BCM2837 (RPi3)
kernel7l.img is 32-bit for BCM2711 (RPi4)
kernel8.img is 64-bit for BCM2837 (RPi3) or ...
- 5,261
12
votes
Accepted
How to revert from rpi-update to stable build
"In normal circumstances there is NEVER a need to run rpi-update as it always gets you to the leading edge firmware and kernel and because that may be a testing version it could leave your RPi ...
- 58.6k
11
votes
Accepted
iptables: nat table does not exist
Quick guess: You've upgraded the OS and the system has been up for a very long time, or managed to upgrade it without replacing the kernel, because the 4.4.11-v7+ modules have already been removed ...
- 58.5k
9
votes
Accepted
How does the pi know which kernel to load?
All the boot magic is in /boot/config.txt.
kernel:
The alternative filename on the boot partition to use when loading the kernel; the default value is kernel.img.
from official documentation
...
- 337
8
votes
How to build My own OS for the raspberry or configure an existing one
to take advantages on the performance
This begs the question that the people who put "an existing OS" together were not concerned about performance, or that you understand it better than them (in ...
- 58.5k
8
votes
Accepted
Enable monitoring mode for RTL8188CUS via USB on Raspbian
Turns out the steps to recompile and load the rtlwifi module are correct. The problem is iwconfig not working to enable/determine monitoring mode in this situation.
Instead, I used iw as outlined by ...
- 331
8
votes
Accepted
Does Raspbian's `/proc/config.gz` contain the running kernel's settings?
Yes; /proc/config.gz, if it exists, always refers to the running kernel's configuration (but see the last few paragraph below) since procfs, like sysfs and devtmpfs, which are used to implement the ...
- 58.5k
8
votes
End kernel panic not syncing cannot allocate swiotlb buffer and cannot provide with dma bouncer buffer
I ran into this same issue with a new install of Pi OS after setting the GPU memory to 896 MB in raspi-config.
To fix it without reinstalling:
Put the SD card in another computer that can read the &...
- 81
7
votes
How compile a loadable kernel module without recompiling kernel
There is a much simpler version here, tested on jessie and stretch.
sudo apt-get install raspberrypi-kernel-headers
and then when your files are in place :
make -C /lib/modules/$(uname -r)/build M=...
- 622
7
votes
Accepted
Raspberry Pi cannot create temp file for here-document: No space left on device
Run the command sudo raspi-config and select the Expand Filesystem option. Then you should be good to go.
- 6,365
7
votes
Pi 3 Raspbian "stretch" (testing) disables wifi
The package that provides the Wi-Fi firmware is called firmware-brcm80211. To downgrade this package to a version that works:
sudo apt-get install firmware-brcm80211=0.43+rpi5
To prevent this ...
- 171
7
votes
failed to start udev kernel device manager
As of systemd 235-2 this still continues with the exact same error.
For people landing here from google:
If you see that after apt dist-upgrade that either udev, journald or even timesyncd are ...
- 171
6
votes
Low Energy Consumption Kernel
The kernel already consumes negligible power. The software loaded on the pi would be the ones munching the most power because of processor time (Apache, databases, networking, etc.)
Here are some ...
- 7,116
6
votes
Accepted
Linux headers generic package not found
I also came across this problem and solved it by following the instructions for a similar question on this forum.
However I did need to make some changes. Specifically, I had to run the following ...
- 176
6
votes
Wireguard "Unknown device type" "Protocol not supported"
According to a comment on r/Wireguard, this error is caused by having the wrong kernel headers:
dkms packages (wireguard-dkms this time) need kernel headers for
current kernel you have loaded (uname -...
- 295
5
votes
Cross-compile x86-64 code on Raspberry Pi 2
It is possible to compile x86_64 code on the Raspberry Pi, and i have just built a cross-compile toolchain on my Pi 2 (with more than 27 hrs of compilation and some hours of bug fixing).
You can ...
- 239
5
votes
Accepted
Essential parts for booting the Raspberry Pi 2
What do I need to sucessfully boot my Raspberry Pi 2 until the init system is loaded? I think I need only the files on the boot partition, because /sbin/init is a symlink to e.g. systemd.
/sbin/init ...
- 58.5k
5
votes
Accepted
Recover pi 2 from wrong kernel build?
All the boot files are on a FAT32 sector, which is readable and writeable by all common operating systems.
You can place the SD card in an SD card reader, delete the bad kernel, and rename the good ...
- 70.5k
5
votes
Raspberry Pi 1 Model B+ end of life?
The rainbow square is an under-voltage warning. You might consider upgrading to a more powerful power supply (more amps, not more volts).
EDIT
To further answer your question I have tried to ...
- 895
5
votes
Accepted
How can I troubleshoot kernel panics?
Is there a way to view the entire logs...?
Your Raspberry Pi typically has a serial console enabled (or can be configured to have a serial console) on one of the built-in UARTs, exposed on GPIO pins ...
- 656
4
votes
How to change the default governor?
I made a small programm to change it and let it be changed every boot by automatically creating an init.d script.
Link to my project
- 41
4
votes
Where is the kernel source for Raspbian's default 3.1.9+ kernel?
You can use rpi-source to automatically find and install kernel sources for your running kernel.
Also see cross compiling from Linux, to avoid waiting for hours to compile your new kernel.
- 141
4
votes
Cannot Emulate Raspberry Pi using Qemu: Kernel Panic
As @dastaan said, the kernel version needs to match the img file. I was trying to use a 4.1 kernel version image file with a 3.18 kernel.
Now that I am using the proper image, it works.
Thanks!
...
- 327
Only top scored, non community-wiki answers of a minimum length are eligible