Is there any way other than device_create() Kernel API and mknod() syscall to...
Is there any way other than device_create() Kernel API and mknod() syscall to create a device file in Linux?
View ArticleKernel zeroes memory?
I am using Debian squeeze and have noticed that memory is always zeroed. Is this new in linux distributions ? Some time ago, I believe I could use puts() and garbage would be output.I run this test...
View ArticleQuick Build Device Tree with yocto/bitbake
I modify the device tree i typically change the dts file.i want to make dtb file from the dts file.but it is showing me some error when i try to bitbake it.IDE=at91-sama5d27_som1_ek SRC=$IDE.dts...
View ArticleRead/Write the MTD flash via Octeon Simple Executive
Cavium Octeon appliance has mtd0 to 5 flash present. I want to log/dump firmware/Simple Executive crash backtrace to one of the flash in the appliance. For that I try to initialize the flash with...
View ArticleChecking if errno != EINTR: what does it mean?
I've found this piece of code used several times (also a similar one where it's used open() instead of write()).int c = write(fd, &v, sizeof(v)); if (c == -1 && errno != EINTR) {...
View ArticleWritable seq_file in Linux Kernel
I'm running some experiments with seq_files and have some confusion regarding it.I analyzed implementation of common functions from seq_file.c and judging by seq_printf implementation the internal char...
View ArticleION and DMA_BUF in linux
Can you explain about use both ion and dma_buf: 1. When need use ion, dma_buf? 2. Why need used in combination ion and dma_buf in linux? Why not use only ion or dma_buf?
View ArticleFedora31 kernel is not loading after a recent upgrade [closed]
I just installed fedora31 on my Dell Inspiron 5567 and ran dnf upgrade --refresh which ran normally and updated all the packages including kernel core and kernel modules. But after I restarted the...
View ArticleHow to restrict anyone (root user also) to modify file in Linux
I am developing one security base software for Linux platform using C and CPP. I want to restrict all users (even root user) also to modify the file. i.e No one can modify the file.Modifying means...
View ArticleBuild Chromium OS with Invalid binary package Error
just try to get started to build with arm64-generic architecture and spent a whole day for this first setup.I have followed the quick-start-guide and got error when i tried to build the image.cros_sdk...
View ArticleHow to suppress the print "SOURCE_MONOTONIC_TIMESTAMP" in linux kernel?
I'm using a custom embedded board based on the imx6sl with a linux kernel.The kernel seem's to add a timestamp every time my application opens a file for writing data. The timestamp seem's to overwrite...
View ArticleLinux kernel crash without kernel logs in my old amd pc [closed]
I've an AMD pc card graphics Radeon HD 6410D, CPU AMD A4-3420 APU with Radeon(tm) HD Graphics. Since I get this PC, it didn't work very well for all linux releases ( fedorea, ubuntu,...
View ArticleHalt instruction from linux kernel module is not working
i wrote a simple linux kernel module to issue 'hlt' instruction#include <linux/kernel.h> #include <linux/module.h> MODULE_LICENSE("GPL"); static int __init test_hello_init(void) {...
View ArticleWhy is an infinite loop sleeping mostly on an isolated core?
I tried the following code to give all execution time by isolating CPU on Centos 8. #include <inttypes.h> #include <pthread.h> #include <sched.h> int main() { volatile uint32_t i = 0;...
View ArticleWhere is the mapping from character or block file to physical address
I've become quite interested in special character / block files in Linux. I have followed a tutorial to create a basic hello world character file, but one thing confuses me. Let's say the motherboard...
View ArticleHow write and execute python code in Lichee Pi nano? [closed]
I have a Lichee Pi nano with me, i just uploaded an image file in to the SD card and details are showing on the display after inserting the SD card into the Licheepi nano. I don't have any input...
View ArticleBUILDROOT ip: can't find device eth0
I have problem with network in buildroot on my VirtualMachine. When i typing ifconfig i get answer:eth0: error fetching interface information: Device not foundWhile loading buildroot on console i...
View Articlewait queues and work queues, do they always go together?
I’ve been trying to refresh my understanding of sleeping in the kernel with regards to wait queues. So started browsing the source code for bcmgenet.c (kernel version 4.4) which is the driver...
View Articleunderstanding jiffy update in work queues
I'm trying to better understand workqueue using the following kernel module#include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/time.h>...
View ArticleRaspberry Pi 4 U-Boot on booting hanging in Starting Kernel
I am working on a project where I want to create my own embedded linux with U-Boot. Therefore I am working with buildroot, which i recently start learning. After successfully creating my own...
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