Building kernel for Android device
I want to build kernel for device Samsung Galaxy core(GT-i8262). The chipset of the device is Qualcomm MSM8225 Snapdragon S4 Play(bootloader msm7627a). Kernel source available on...
View ArticleHow to exactly limit a certain linux user process's usage of cpu resources?
How to exactly limit a certain linux user process the usage of cpu resources?I do not think the scheduling policy works.You could not limit the cpu usage of a user process under a certain level even if...
View ArticleWhat is an “irqchip”?
In reference to the QEMU x86_64 machine optionkernel_irqchip=on|off, the description reads:Controls in-kernel irqchip support for the chosen accelerator when availableWhat is an "irqchip"?
View ArticleAdding new Linux kernel to Ubuntu 20.04 LTS unable to boot [closed]
I have just installed Ubuntu 20.04 LTS onto my Lenovo X250, it came with kernel 5.4.0-31-generic and boots fine into it. I need to add some older kernels to be able to boot up into for driver testing...
View ArticleDoes the clock sources of timer(`timer_create, timer_settime`) and...
Is there any difference in the implementation of timer(timer_create, timer_settime) and nanosleep under Linux?Are they use the same clock source?
View ArticleHow Can I Use a PCI Device's Memory as System Memory
In Linux, say I have a PCI device that has a large amount of on-board idle memory, and the driver for it is able to effectively communicate with that memory region in a load/store manner. There is a...
View ArticleLinux shared library loading and sharing the code with other process
Suppose I have a shared library a.so which is loaded for the first time by my executable. My understanding is that to the middle of VMA, the shared library text sections are mapped. I have two...
View ArticleConfusing /dev/video and /dev/fd in Linux
I am confused with /dev/fdX and /dev/videoX.I know /dev/videoX is input device, such as a camera, and seems also support support output, but I did not know what it output?/dev/fdX is also a image...
View ArticleConfusing /dev/video and /dev/fb in Linux [closed]
I am confused with /dev/fbX and /dev/videoX.I know /dev/videoX is input device, such as a camera, and seems also support support output, but I did not know what it output?/dev/fbX is also a image...
View Articleyocto Linux kernel build: vmlinux and initrd creation
With a Yocto kernel build, core-image-base, qemux86_64:How do I get Yocto to generate the vmlinux (not vmlinuz) and initrd.Where can I find these when using a automated script.The script usage is in...
View ArticleHow to build and deploy BPF BCC C++ apps?
There's plenty of docs for python developers, but as a C++ developer very new to BCC/BPF i'm finding it very difficult to determine where to start in building and deploying BCC-based C++ apps.Where do...
View ArticleHow to have a Linux USB gadget and network driver talk to eachother
We're currently targeting kernel version 5.4.I have a driver that relays stream data sent over a sock through USB to another device that performs operations with the data (device <-> host...
View ArticleHow to compile BCC on Ubuntu 20.04?
I am trying to compile the BCC BPF framework (https://github.com/iovisor/bcc) on Ubuntu 20.04. I followed all the instructions for 18.04, but of course; they fail.The issue i have seems to be...
View ArticleKernel: how to iterate the children of the current process?
In Linux Kernel Development, 3rd ed, this code was given for traversing the children of the current process. list_for_each(list, ¤t->children) { task = list_entry(list, struct task_struct,...
View Articleproc/[pid[/stat file unrecognizable output
When I read the stat file following output comes15465 (out1) S 15290 15465 15290 34817 15465 4202496 185 0 0 0 0 0 0 0 20 0 1 0 1505506 4263936 89 18446744073709551615 4194304 4196524 140733951429456...
View ArticlePairing acquire / release operations between user and kernel space
I am trying to ensure proper synchronization over a piece of memory shared between a user thread and another thread running in kernel mode on Linux.Does it make sense to pair a C11's...
View ArticleHow do I understand kernel oops error code?
I want to compile my linux kernel with GCC10.1 instead of GCC7.5 which I used before.Sadly, the kernel does not boot fully on my device, I believe its sound that causesLog:...
View ArticleOperating System Linux with VB.NET [closed]
Hello everyone I was thinking of creating a very basic and simple operating system in vb net I already have everything planned but there is one thing I wanted to make a real bootable system that was...
View Articleonly 2 PERF_TYPE_HW_CACHE events in perf event group
Working on a custom implementation on top of perf_event_open I need to monitor multiple PERF_TYPE_HW_CACHE concurrently.The Intel manual states that there are 4 programmable counters per thread (or 8...
View ArticleMake file error when compiling kernel module
Hello i am trying to compile my first kernel module but i am receiving an error message. The hello.c program for my module is shown below:#include <linux/init.h>#include...
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