embedded-linux

问题 I am trying to compile a new Linux kernel obtained from https://github.com/qoriq-open-source/linux (version 4.9) for T1042D4RDB-64B embedded board using Yocto . It's currently using 4.1.35-rt41 . I followed these steps: bitbake virtual/kernel -c cleansstate bitbake virtual/kernel -c patch replacing git folder with my new kernels source code (https://github.com/qoriq-open-source/linux) make ARCH=powerpc menuconfig bitbake virtual/kernel Result is The new kernel has compiled successfully but

问题 I used to update firmware on embedded system through tools like tftp (with ethernet port or ethernet over usb), sd card or a simple usb stick. I am currently working on a system without ethernet port, no usb port. Only a ttl/usb connexion to be able to access the console and a micro usb to supply it. I am currently building a linux image and a rootfs. The storage used on the board is emmc. Is there a standard way to update linux/rootfs in Emmc, etc.. with u-boot by using a simple ttl/usb

问题 Currently I am working on yocto OS for my project. My question regarding debug. In normal practice the debug information is entertained through serial. I aware about ssh debug. I have two question.... Why normally every device support debug on serial port? Is there any possible way to get debug through USB PORT(with out using serial to USB converter) in Yocto? 回答1: Because serial driver can be simple and implementing without interrupts (how Linux kernel console actually does). This is a

问题 I am studying about Linux Interrupt handling mechanism, just got doubt whether registering an interrupt handler from user-space is allowed or not? 回答1: No, interrupts are registered in the kernel and a driver / module must be loaded into kernel space to receive the interrupt. It could pass handling onto a user space daemon that hooks into the kernel module, but the something must be inserted into the kernel. 回答2: Cannot register user space interrupt handler directly. Kernel ISR indicates

问题 I need to play more than 2 wav files using ALSA library C interface. Each file should be played with different volumes but it should be possible to play them simultaneously. I am using embedded linux on a board with sgtl5000 device. I get only one entry for playback device as pcm0p. Please let me know how to play multiple sounds together with different volumes. Please let me know if you require more details. Thanks in advance 回答1: If the ALSA library has been compiled with the dmix plugin,

问题 Question My question is, What does linuxrc do? Do i need it in my rootfs ? Does it have anything to do with using systemd vs initd ? Background I am currently attempting to build a rootfs for an ARM 7 processor using Yocto. The only modification I have made to the original BSP project is I specified that I would like to use systemd as my initialization manager (done in local.conf ). The rootfs builds ( bitbake core-image-minimal ) and using Mgftool2 I load it onto the board. When I attempt to

问题 Question My question is, What does linuxrc do? Do i need it in my rootfs ? Does it have anything to do with using systemd vs initd ? Background I am currently attempting to build a rootfs for an ARM 7 processor using Yocto. The only modification I have made to the original BSP project is I specified that I would like to use systemd as my initialization manager (done in local.conf ). The rootfs builds ( bitbake core-image-minimal ) and using Mgftool2 I load it onto the board. When I attempt to

问题 My aim is to control the GPIO pins in Peppermint 4 Linux (Kernel version 3.8.0) on an Intel motherboard (NM70 chipset with C1037U processor). How can you check whether your kernel supports GPIO on your hardware? Background Motherboard: Intel with NM70 chipset Processor: C1037U processor OS: Peppermint 4 Linux Kernel version: 3.8.0 GPIO interface: sysfs I'm attempting to use the sysfs interface, which allows GPIO pins to be accessed from userspace through the filesystem. I’ve successfully

问题 I'm creating a camera driver for Android. I've got my mydriver.c file. Apparently I need to compile it into a .ko, is that right ? And then to load it I should do a #insmod ./mymodule.ko , will it work ? Do I need to be root ? And how I put the .ko file on my Android tablet ? 回答1: Yes, you need to be root. And, insmod ./yourmodule.ko should work fine. 回答2: Are you trying to make this new camera work as a standard camera through Android's camera API? In that case, unless your tablet has a

问题 I have gone through some driver implementation in Linux Kernel Source and can see that these are the platform driver. drivers/net/ethernet/smsc/smsc911x.c static struct platform_driver smc911x_driver = { .probe = smc911x_drv_probe, .remove = smc911x_drv_remove, .suspend = smc911x_drv_suspend, .resume = smc911x_drv_resume, .driver = { .name = CARDNAME, .owner = THIS_MODULE, }, }; Above is a driver for platform device(smsc based Ethernet controller) and platform devices are devices which are