Does every Linux fd have a buffer?
After the client connects to the server, the input on the server terminal will be blocked until the client disconnects. Is this blocked data in the terminal's buffer?What happens if the input data is...
View ArticleYocto linux on rpi 3b+, bootup issue. mmc1 is not getting hardware interrupt
I tried to bootup RPi 3b+ with Yocto Linux (kernel v4.19) (console image) but its not booting up. I suspect its something related to i2c or interrupt.Note: I have taken care of device tree and overlay....
View Articleip6tables-restore v1.6.0: Couldn't load match `httphost':No such file or...
I am getting the following error when I use iptables-restore, Could someone help me to get this? ,Here xxx is a proprietary one.-A xxxx -p tcp -m tcp --dport 443 -m httphost --host "www.hp.com" -j...
View ArticleEmbedded Buildroot and Yocto Linux crash 50% of the time
I am getting the below error 50% of the time during startup on an STM32 based processor (OSD32MP15x).I've tried over 40 versions configs and setups none work and I am under high pressure to deliver...
View ArticleKernel Makefile does not create any .ko file for my module
I want to make very simple module. So, I just made a hello_module.c file and a Makefile.Makefile:obj-m := hello_module.oKERNEL_DIR := /lib/modules/$(shell uname -r)/buildPWD := $(shell pwd)default:...
View Articlehardirq and softirq run on the same core/processor?
Assume I have RSS and interrupt affinity correctly set up.Is it guaranteed by the Linux kernel that a softirq is executed on the same CPU/core where hardware interrupt handler has been triggered? I...
View ArticleWhere does dprintf(INFO...) or dprintf(CRITICAL...) go in Android LK
I'm working on a project that is using an Intrinsyc OpenQ-2500 development kit. The kit uses an APQ8909W snapdragon processor, which is running a modified version of Oreo 8.1.I'm attempting to bring up...
View Articlemmap implementation in glibc - dynamic library with symbol mmap
I wanted to see how the Linux kernel function mmap() is implemented, so I downloaded the GNU C Library (glibc) source from the GNU page. (I downloaded glibc-2.27 because ldd --version told me I was...
View ArticleHow to make GPIO init before MII init
I want to make GPIO-driven reset on 2 PHY chips inside DUAL EMAC on TI AM3352.Because drivers don't have the ability, I have made a mod in mdio_bus.c driver, function mdiobus_register_gpiod :if (gpiod...
View ArticleLinux kernel source git checkout to specific version
When I am in Linux kernel git local repo and want to git checkout to some specific version of sources I see e.g. the following options:git checkout v4.4v4.4 v4.4-rc1 v4.4-rc2 v4.4-rc3 v4.4-rc4 v4.4-rc5...
View ArticleUSB deregistration issue
I have a USB device that sometims does not deregister itself from the device tree when the power is pulled off. I can still see it under the list of lsusb.Basically, I get two types of error logs under...
View ArticleThe vboxdrv kernel module is not loaded (Unknown rela relocation - debian...
Virtualbox fails to load kernel module after updating Debian from Stretch to Buster.I have Virtualbox 6.1 and the next kernel version:~$ uname -a Linux debian 4.9.0-4-amd64 #1 SMP Debian...
View ArticleCross-compiling kernel tools, cannot find -lelf even with -L set correctly
I'm trying to cross-compile a modified version of the official Debian kernel for armhf on my amd64 machine. I'm using the HowToCrossBuildAnOfficialDebianKernelPackage instructions on the Debian...
View Articlehow can I traverse all devices attached to system and get their struct device...
I want to write a function in my custom kernel module, which can perform 'traverse through all devices attached to system and get their struct device*', in order to unregister all device drivers using...
View ArticleHow to enable wake on usb (remote wakeup) in android?
I have an AOSP tree compiled on my board. I bought a wireless keyboard and connected it to my board via usb port. I expect when the board is in the suspend state, it will wakeup by pressing a key on...
View ArticleHow to enable CONFIG_PREEMPT option in Linux kernel?
I am new bee in Linux kernel programming, trying to work with an old kernel Linux 2.6.32 on x86_64. I want to enable the CONFIG_PREEMPT option in it but can not find information about how can I do it....
View ArticleRecompiling linux kernel
i need help about recompiling kali linux kernel on a Raspberry pi 4.The version of my kernel is:4.19.118-Re4son-v8l+First i downloaded from https://www.kernel.org/, i chose the version:4.19.155After...
View ArticleHow can I determine what USB Wifi devices are supported by specific kernel...
I'm trying to add a USB Wifi device to an older device (Kernel 3.0.35). I can't update this device and want to find a device that is supported by drivers already existing on the device.I've checked my...
View ArticleStatic variables in the defining file of a C linux __kernel__ syscall [closed]
The set of syscalls I'm writing is supposed to maintain a set of data that any program can access. I have a static pointer I'm intending to be accessed by the syscalls that contains a fixed length...
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kernel panic not syncing no working init found - during Ubuntu installation...
today i wanted to switch my OS on ubuntu but i have some struggle with it. My laptop: IdeaPad S340 has some problem with new OS. During booting there appear some error. I am already in ACHI mode and I...
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