Errors when install QEMU from source code
When I want to install QEMU from source code, I followed this article's recommended method of installation Emulating CXL Shared Memory Devices in QEMU.when I started to make ,errors...
View ArticleModify fsl_sai.c to have constant clock
I am using a chip connected to the i.MX via SPI and I2S. According to the manufacturer (and confirmed by me), the chip’s internal clock runs only when an I2S clock is present. The SPI clock alone is...
View Articleproc_create() example for kernel module
Can someone give me proc_create() example? Earlier they used create_proc_entry() in the kernel but now they are using proc_create().
View ArticleeBPF ring-buffers are not printing event to the stdout, evt struct is...
I have following program structure:src/main.bpf.c:#include "../vmlinux.h"#include <bpf/bpf_helpers.h>#include <bpf/bpf_tracing.h>#include <bpf/bpf_endian.h>#include...
View ArticleHow to write/attach a "device-bound" XDP program so that I can use XDP...
I want to use the kfunc bpf_xdp_metadata_rx_hash to get the flow hash in an XDP program as follows:#include "vmlinux.h"#include <bpf/bpf_helpers.h>extern int bpf_xdp_metadata_rx_hash(const struct...
View ArticleAndroid Binder Tracing
In Android OS source code (Path: /drivers/staging/android/binder_trace.h), we have a file named binder_trace.h and also in /drivers/staging/android/binder.cbinder_trace is included. As we can see in...
View ArticleWhat's the difference between chroot and pivot_root?
During my learning of docker, I hear that the Linux command chroot is not enough to isolate the container and we need a new command called pivot_root, why? I look up the manual for them but just be...
View ArticleHow vruntime of a newly created process initialised in CFS scheduler linux ?
In CFS scheduler, it always picks a process with minimum vruntime. vruntime of a running process is increased by the amount of CPU it consumes.I have following two questions related to CFS and...
View ArticleHow to dereference device_private in struct device
I'm working on a driver in Linux. I'm working on getting some /sys file attributes in place. In delivering what these attributes are to convey, the attribute functions must have access to some data...
View ArticleDebian-SMC: System is auto rebooting randomly [closed]
My server is experiencing random reboots, and I haven't been able to locate any logs explaining the cause.Below are the system details.OS: Debian 12.8 (bookworm)Hardware: SMC (SYS-111E-FWTR)kernel:...
View ArticleAccess PSA-5000 console
Hope you're doing well.I'm experiencing an issue with accessing the terminal/console on a PSA-5000 (Pulse Secure) device. The device runs on a Linux-based OS(correct If I'm wrong), and when I try to...
View ArticleWarning from rcu_note_context_switch in custom Linux kernel
I am working on a custom platform running embedded Linux with custom kernel modules (I have no access to them).From time to time, the following message appears on the console:[ 634.900724]...
View ArticleWhy arm processor prefetch the overlapped memory address?
The code below is part of the copy_template.S code in Linux. UNWIND( .fnstart ) enter r4, UNWIND(fpreg,) lr UNWIND( .setfp fpreg, sp ) UNWIND( mov fpreg, sp ) subs r2, r2, #4 blt 8f ands ip, r0, #3...
View Articlecopy_from_user and copy_to_user overhead
I’ve been diving into the overhead of copy_from_user and copy_to_user, but I’m having a hard time getting a clear understanding of how much more expensive they are compared to a simple memcpy.I’ve gone...
View ArticleERROR: modinfo: could not find module
I am installing new kernel 3.12.x on redhat 6 machine. Below is my steps which I followed to install the new kernel.extract kernel in /usr/src/ directorySwitch to cd /usr/src/linux-3.12.xmake...
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How to reliably determine which USB device under /sys/device corresponds to...
Here my problem: most of Qnap's NAS feature a "copy" button on the front, next to a USB-A port. That button will copy the content of any hard-drive plugged to the USB port next to it.I want to develop...
View Articlendo_start_xmit() not called when using cansend command
A little background, I want to receive CAN frames to Linux SOM, which does not have CAN peripheral, so I use stm32 which acts just like a bridge that sends CAN frames over UART to SoM. That part is...
View ArticleHow to print out what module is shutting down in Linux kernel when rebooting
I am debugging an issue where the error occurs when one of the Linux module shutdowns when rebooting the system.I am wondering how can I print what module is shutting down when rebooting in Linux...
View Articlemanually modifying stack pointer inside a kernel module aarch64
I am writing a kernel module in Linux, on aarch64 architecture, that has, as a global, a structure. I am working on a Pixel 8 device (shiba), with callyxos, AOSP (android open source project) kernel...
View ArticleHow to use dt schema for device tree validation in yocto project
I want to use dt validation for my kernel build in yocto projects. I noticed 2 recipes python3-dtschema-wrapper.bb and python3-dtschema.bb but I'm unclear about how to properly use them to validate my...
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