embedded-linux

问题 On my x86_64 board, there is i2c-bus coming out of a MFD device. There are devices on to this i2c-bus. I am able to detect these devices using i2cdetect program. # i2cdetect -y 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- 4c -- -- -- 50: -- -- -- -- -- -- -- 57 -- -- -

问题 I am trying to boot Linux via U-boot on a custom board with i.MX6 (CPU core is ARM Cortex A9) We seem to have ported Das U-Boot(2009.08) successfully. But booting Linux fails at the last U-Boot message: "Starting kernel ..." Here is my relevant environment: bootargs=console=ttymxc1,115200 vmalloc=400M root=/dev/mmcblk0p1 rootwait consoleblank=0 earlyprintk video=mxcfb0:dev=lcd,LCD-ORTUS,if=RGB24 video=mxcfb1:dev=hdmi,1280x720M@60,if=RGB24 calibration tsdev=tsc2004 fbmem=10M,28M bootcmd

问题 I am trying to mock a function (for unit testing parent function) using GDB. One way to do it would be to set a break point in function you intend to mock and use GDB return command. However I am unable to do the same when GDB call command is used. (gdb) b secret_check Breakpoint 1 at 0x80483ba: file ut_gdb.c, line 6. (gdb) start Temporary breakpoint 2 at 0x804843c: file ut_gdb.c, line 34. Starting program: ut.bin Temporary breakpoint 2, main () at ut_gdb.c:34 34 int res = 0; (gdb) bt #0 main

问题 I have recently started learning to write Linux device drivers for a specific project that I am working on. Previously most of the work I have done has been with devices running no OS so Linux drivers and development is somewhat new to me. For the project I am working on I have an embedded system running a Linux based operating system. I have an external device with is controlled via RS232 that I need to write a driver for. Questions: 1) Is there a way to access serial ports from withing

问题 Problem: I have to configure various LCD displays to be used by Android Platform. Almost in all cases there are no electrical specifications freely available for LCD displays on interest. But through experience and reverse engineering the parameters can be guessed reasonably well. I am trying to use Loadable Kernel Modules to fine tune the display parameters (any other suggestions are welcome too). Please find the relevant information below. HW: Atmel SAMA5D31-EK (ARM 5 processor) SW: Andriod

问题 After giving sometime i am able to compile qvfb for host x11 enviroment. Now i am looking forward to run QT embedded linux demo program inside it. But i am not successful in this http://doc.qt.io/qt-4.8/install-x11.html Here i have configured QT source for x11 taking into refrence above link & my qvfb is lying at this location :--- ~/qt_source/qt_source_x11/qt-everywhere-opensource-src-4.8.5/bin . http://wiki.qt.io/Building_Qt_for_Embedded_Linux Here i have refered above link & configured &

问题 I'm facing some problems while developing an Qt-based embedded solution for Linux. Basically my application plots a QwtPlot graph with up to 8 QwtPlotCurves attached to it. A QwtPlot::replot() is called each 1 second. Data arrives from a socket connection connected to another .c app in the same system. Hardware is a Texas' OMAP. The problem is that depending on the configuration, the replot becomes very, very slow. To be more specific, if I put 4 curves to be shown, no delay is perceived, but

问题 Can we use gevent.sleep() anywhere in our application or gevent.monkey.patch_time() on any third party libraries without an issue, especially precise timings takes place? For example, some libraries use time.sleep() function in order to measure a couple of microseconds that is used to control an embedded (dot matrix LCD and such) device. Can we safely monkey patch such libraries without a problem? 回答1: No. gevent.sleep() is not suitable for precise timings. Here is the test code: import

问题 I want to control the GPIO on the Jetway Atom PC JBC373F38 (http://www.jetwaycomputer.com/JBC373F38.html). I have found that the GPIO on that PC is part (GPIO3) of the super IO chip Fintek F71869A. I has make a small code to control these GPIO pin on Linux using 0x2E/0x2F ports but it does not work. May any one have working example for this problem or tell me what is my mistake in my code. This is my code: #define AddrPort 0x2E #define DataPort 0x2F #define WriteByte(port, val) outb(val, port

问题 I am doing some experiments on SAMA5D27-SOM1-EK1 board. I am using Linux operating system. I am exploiting GPIOS of my board. There is RED LED defined at GPIO 10 and USER button defined at GPIO 29 . I wrote C++ program to control LED of the board and here is the code : #include<iostream> #include<fstream> #include<string> using namespace std; #define LED0_PATH "/sys/class/leds/red" void removeTrigger(){ // remove the trigger from the LED std::fstream fs; fs.open( LED0_PATH "/trigger", std: