I compiled goldfish kernel with: I started the AVD with the compiled kernel. emulator -kernel goldfish/arch/arm/boot/zImage -avd TestAVD I pushed a compiled c program onto AVD. And I downloaded the libs (I’m not sure if it’s the proper way) run gdbserver: forward port: run gdb specify the search d…
Tag: linux-kernel
updating product/vendor id on Raspberry Pi (CP210X)
Running “uname -a” on my Raspberry Pi will yield the following: Linux tm-gw 4.4.14-v7+ #896 SMP Sat Jul 2 15:09:43 BST 2016 armv7l GNU/Linux My problem is that I have a USB device which vendor and product ID isn’t registered in CP210x.c file, which – again – means that even thoug…
Docker container: lsmod not found
How can I get lsmod and modprobe installed in Ubuntu 14 that is running on Docker? I need to install a device driver in the container, but first I need these commands. (The docker image is originally from docker hub, from a tomcat:7 image). Answer Based on comment from @lan-Abbott. Problem is solved.
tickless kernel , isolcpus,nohz_full,and rcu_nocbs
I have add “isolcpus=3 nohz_full=3 rcu_nocbs=3” in grub.conf in RedHat 7.1 , kernel: linux 3.10.0-229 kernel and according to http://www.breakage.org/2013/11/15/nohz_fullgodmode/ I also execute the following command : The box has only 4 cpu cores , I run the following shell : look like work perfec…
Where are inodes stored at?
I recently started learning about the Linux kernel and I just learned about inodes, which are data-structures containing meta-data of a file. Now, how do the OS find the associated inode of a file? (Let’s say a string of a path). Moreover, where are those inode stored at? I mean, obviously they are stor…
Are sysfs binary attributes allowed to return more than one page of data?
I’m writing a linux device driver that, among other things, exposes a readonly binary attribute in sysfs, the interface for which is When I try to cat or hexdump the file, after the first 4096 bytes, my driver will be given a zero-sized read (It is passed 0 for size). Why is this happening, and how shou…
register protocol handler for a transport protocol in Linux kernel
I’m trying to implement the QUIC protocol in the Linux kernel. Since QUIC is working on top of UDP, I’ve been using the UDP code as a learning base. Now I want to register the protocol handler for the QUIC protocol but I don’t understand how and where to do it as I can’t find the relev…
Linux DMA: Using the DMAengine for scatter-gather transactions
I try to use the DMAengine API from a custom kernel driver to perform a scatter-gather operation. I have a contiguous memory region as source and I want to copy its data in several distributed buffers through a scatterlist structure. The DMA controller is the PL330 one that supports the DMAengine API (see PL3…
How to make LKM multi-process safe?
I make simple LKM (Linux kernel module) to interact my MPI application (multi process per one compute node) at user level with kernel level information. I need to extract some data from kernel to the user level application at runtime. My MPI application uses few processes run on the same compute node simultan…
Can bash be used to communicate directly with hardware?
I am interested in writing my own tool in bash to act in place of my current network controller (wpa_supplicant) if possible. For example if I want to issue commands in order to begin a wps authentication session with a router’s external registrar, is it possible, without using any pre-built tools, to c…