embedded-linux

问题 i'd like to use the advanced features of ftrace but i dit not figure out how. debugfs is mounted but there is no "tracing"-folder in /sys/kernel/debug. i am running a ARM-Target @ Angstrom distro build via yocto, please see : Image: uname -a & lsb_release -a output zcat /proc/config.gz | grep TRACER|FTRACE output How to configure the kernel ? which options i have to set? 回答1: Add below kernel config options in your yocto project conf/local.conf file & then clean & rebuild linux kernel. KERNEL

问题 I want to create a Yocto layer for the CANBOAT Repository for phyBOARD Mira board which will be connected to a NMEA2000 on a boat. I would like to read different PGN values and store it in a database. configuration I have a Linux Virtual Machine (Ubuntu 16.04 LTS) Linux ubuntu 4.13.0-39-generic #44~16.04.1-Ubuntu SMP Thu Apr 5 16:43:10 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux I have all the meta layers in a folder called sources in the $YOCTO_DIR . Within the sources I have created the meta

问题 I need to send a string from kernel to a user space function without asking for it in particular from the user space, sort of triggering a function or application in the user space via some event in kernel. So far I have tried an Ioctl that starts on an init in user space and then sleeps and kept reading about netlink but couldn't find a good working example for it. Any suggestions or examples will be much obliged. 回答1: Here's how my process works, I would be interested in any suggestions for

问题 I am having troubles getting a touch screen powered by an Atmel MXT641T on an Android 5 platform to work. The setup I have is as follows: Hardware: Inforce 6309 SBC with Qualcomm Snapdragon 410 msm8916 ARM64 processor. Custom touch screen with Atmel MXT641T controller chip. I2C connection between Atmel and Snapdragon connected to I2C0. Android 5 operating system using Linux kernel 3.10 from git://codeaurora.org/kernel/msm-3.10.git branch Rel_V1.3 (this is part of the BSP that comes with the

问题 How do I calculate network utilization for both transmit and receive either using C or a shell script? My system is an embedded linux. My current method is to recorded bytes received (b1), wait 1 second, then recorded again (b2). Then knowing the link speed, I calculate the percentage of the receive bandwidth used. receive utilization = (((b2 - b1)*8)/link_speed)*100 is there a better method? 回答1: Check out open source programs that does something similar. My search turned up a little tool

问题 I am working on including a shared object file onto the Android OS image through the NDK project. The android.mk file looks like this LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := Myaccessories LOCAL_SRC_FILES := libMyaccessories.so include $(PREBUILT_SHARED_LIBRARY) And I have added the "libMyaccessories.so" to the jni folder where the android.mk is located. On ndk-built, it results in error which is as below Prebuilt : libMyaccessories.so <= jni/ Install :

问题 I'm trying to setup Bluetooth on an embedded Linux device such that SSP mode is used, with my device generating and displaying a passcode on it's display, and the remote end (e.g. user's phone) being required to enter the matching passcode to be able to successfully pair. I'm written/registered an agent that sets it's mode to DisplayOnly; I expected that when a device connects the "RequestPasskey" callback would be called and that my agent would then be able to generate and return a new

问题 I have compiled QtWebEngine into my i.MX6 embedded device. When I tried to play youtube Video with quicknanobrowser, the video plays but there would be no sound. In fact, there is no sound when I try to test play the audio files in hpr.dogphilosophy.net/test even though the website said that the browser codec is supported. I have enabled pulseaudio, gstreamer, ffmpeg, opus, vpx, libwebp and yet still no sound. However, I could play video with gst-launch and there would be sound. Is it

问题 I'm having a lot of trouble installing Java on my Poky Linux system. I'm building my system using Yocto with the following configuration: local.conf MACHINE ??= "intel-corei7-64" DISTRO ?= "poky" PACKAGE_CLASSES ?= "package_rpm" SDKMACHINE ?= "x86_64" EXTRA_IMAGE_FEATURES ?= "debug-tweaks" USER_CLASSES ?= "buildstats image-mklibs image-prelink" PATCHRESOLVE = "noop" BB_DISKMON_DIRS = "\ STOPTASKS,${TMPDIR},1G,100K \ STOPTASKS,${DL_DIR},1G,100K \ STOPTASKS,${SSTATE_DIR},1G,100K \ STOPTASKS,

问题 I am using beaglebone to access digital input from specific pin using sysfs interface. And I can change the output states but not the input :(. What I did is, I have two pins pinA and pinB. pinA I made it output and pinB I made input. Connected pinA to pinB. Configured pinA as output pin by sending out to direction attribute in sysfs and pinB as input by passing in. And I changed value of PinA to 1 and it is giving 1 as output (I tested using LED). But when I read the value of PinB it is