Questions tagged [embedded]

The use of Unix in embedded computer systems such as networking equipment, mobile phones, media players, set-top boxes, etc.

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Cannot edit or delete read only file(s) in embedded linux

i have this hardware piece: it called: airfiber x5 this device can be accessed through SSH using putty program or WinSCP to view its operating system's files it has an embedded web interface, ...
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1answer
896 views

Fdisk does not match /proc/partitions or mount points (embedded)

I'm working on an existing embedded Linux device and am having trouble editing the partitions using fdisk. My goal is to create a partition for testing purposes on /dev/sda. I am using the fdisk ...
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0answers
39 views

Minimum ram we can achieve with Linux only blinking led

I heard of uclinux and Linux tiny project are very ambitious projects. It uses concept called XiP to reduce memory footprint. We can strip down binary and storage is less of a problem but connection ...
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1answer
532 views

Save U-Boot environment variables without Flash connected

I've seen multiple blog posts of people getting around the U-Boot bootdelay 0 environment variable to get to the U-Boot CLI. An example is here. The general process, as I understand it, is: Desolder/...
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1answer
73 views

arp-scan shows machines, but I can't ping some of them

I am working on an embedded linux board with a freescale cpu and an ltib built linux on it. The appliance has two network interfaces and here is the output of ifconfig and route commands: [root@sina-...
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393 views

How to connect to my phone via bluetooth serial

I am having trouble connecting to my phone via serial bluetooth on an embedded linux system. Here are the steps that I have taken to attempt a connection. (Note that I am able to pair and connect just ...
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1answer
756 views

How to fix reboot broken by kernel update

I am working on an embedded system built around Atmel ARM926EJ-S based on rather old ARM core ARMv5TEJ. I have a Debian 8 system that used to work for that hardware until I had to update the kernel ...
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1answer
101 views

Do I need to learn a RTOS first or can I directly go for embedded Linux? [closed]

If I wanted to learn deeply and build a embedded Linux Operating systems would i benefit from knowing about RTOS or can I straight away go for embedded Linux.
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1answer
4k views

Access root filesystem from U-boot

I'm trying to debug an embedded device, connection via serial port, connected with USB to UART cable. Embedded Linux v.2.6.26.5 How to access the root filesystem "/" and subdirectories under the root ...
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1answer
41 views

Is there a difference starting an application by script or by hand in the terminal

I have an embedded linux device and a Qt application. If I start my application in the terminal (with /opt/myApp) then it runs with good Performance (touch buttons react immediately). If I let it ...
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1answer
583 views

Hardware accelerated h.264 transcoding on i.MX6

Preface: I have a lot of .mts video recordings (mainly 576 to 720 lines) I need to cut and transcode to lower bitrate h.264. Nowadays I do this on with an all-in-one tool on my 2009 Core2Duo MacBook, ...
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1answer
1k views

Get the CPU temperature on poky linux

I'm monitoring the performance of an ARM-based embedded device which runs poky linux distro (from Yocto project) which contains OpenEmbedded build system. I need to get the CPU temperature time and ...
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577 views

ARM system booting from SD card with uboot - how to put everything in one FAT partition?

I am working on an ARM system running linux, which has an eMMC and an SD card slot. I've been booting from the SD card during development, with just the first stage bootloader of uboot in the eMMC and ...
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1answer
2k views

How to load files from an EMMC's General Purpose Partition or Boot Partition, using Uboot

Is UBoot able to boot via fatload/ext4load from an EMMC's General Purpose Partition or Boot Partition? I am able to show files from the User area, just not partitions created as hardware partitions. ...
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0answers
348 views

Why do I get a random MAC address every boot in a linux embedded system?

I started messing around with my raspberry pi and I build a simple linux embedded system using buildroot and I found my IP address was different to what I was expecting (I had DHCP configured) then I ...
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3answers
9k views

Converting from binary to hex and back

Given a binary file, how do you convert it to a hex string and back, using only standard tools like sed and cut, on a minimal system with busybox installed? These tools are not available: perl ...
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1answer
45 views

Getting Git repo onto BusyBox system (StarDot NetCam SC)

The StarDot NetCam SC comes with ucLinux and Busybox. I am struggling to load a Git repository onto the device. No git No SSH so I cannot scp No support for HTTPS so I cannot wget directly from ...
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2answers
857 views

apt-get upgrade doesn't find newest packages

Recently Debian Wheezy LTS released a new version of a package, e.g. wget 1.13.4-3+deb7u4 (see announcement here), on my system I still have an old version e.g. wget 1.13.4-3+deb7u3 installed. My ...
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1answer
290 views

Run Linux on RISC STi7105BKUD?

I have this board with the STi7105BKUD chip on it, along with ram, flash, and a lot of I/O. Reading the documentation for this chip (here) I can see it has the ST40-300 processor embedded into it ; ...
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0answers
184 views

Minimalistic Framebuffer showing text and progress only

I have an embedded linux system with framebuffer only. Normally a Qt Application is running. During update situation the application is stoped and I would like to use the framebuffer device to show ...
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1answer
44 views

FTP download question

An embedded device, running eCos OS, with FTP Lite Client. I want download file from device to local PC via FTP during terminal session. FTP transfer initiates device, it ask to specify the FTP IP ...
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1answer
267 views

How does swappiness affect the longevity of SDHC memory cards in embedded computers?

In this question over at superuser several answers report SDHC card failures in Raspberry Pi single-board computers and other embedded devices over the course of periods varying from weeks to years. ...
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1answer
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Configure systemd in mounted root (i.e. offline)

I am trying to bootstrap and configure an embedded system. I need to enable certain systemd services (e.g. networkd, resolved). I'm working on an x86* machine while the one that I'm configuring is ...
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1answer
2k views

Getting a 3G modem connected automatically on embedded Debian 8

I am working on a Debian 8 system that I run on custom hardware built around ARM926, aiming to get 3G modems connect automatically when the system is powered on. I am using Raspberry Pi and Raspbian ...
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1answer
371 views

Although users exist in /etc/passwd, but only one of them able to login

Output from /etc/passwd admin:VyaVORqi23kjg:0:0:Administrator:/:/bin/sh user1:VyaVORqi23kjg:0:0:User1:/:/bin/sh user:VyaVORqi23kjg:0:0:User:/:/bin/sh nobody:p/hyihIrG/5hM:0:0:nobody for ftp:/:/bin/sh ...
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How to access a keyboard in embedded device

I'm working with an embedded device that has a display with a touch screen, but to this point, no keyboard. There is a console that is accessible via a connector that isn't user accessible. The ...
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2answers
7k views

How to install Linux on arm processors

I work on arm cortex-m3 microcontrollers for 3,5 months.I made several projects and programmed directly with st arm debugger for real time operations(motor drive, sensor and actuator applications....)....
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1answer
920 views

Is a device tree blob tied to a specific linux kernel version?

I was asking myself if a certain dtb that works with linux kernel version 3.18 is compatible with a linux kernel version 4.9. I suppose not, because kernel code concerning the device tree likely ...
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1answer
380 views

Disable waiting and writing 'C' in u-boot SPL? - am335x, u-boot v2014.07

I use u-boot 2014.07 from denx git repository in our board. This u-boot gives me after compilation two files : u-boot.bin and MLO. MLO is first bootloader. I put both on sdcard first partition ...
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43 views

How to make sure linux machine boots if RAID 1 boot drive fails

I am designing a system that includes a linux (Debian) based control computer. It will be deployed to a remote, inaccessible location. I want to set it up in such a way to maximize the chance that it ...
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1answer
175 views

Can we kill inetd if there's nothing using it / no config?

In a small embedded Linux Busybox based system, by default inetd is being started at boot but inetd.conf has every service commented out as none of them are being used. Does this mean we can just ...
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2answers
81 views

How to access a dynamic module by a user application

i created a simple dynamic module(.ko).How can a user application can access driver from the kernel space.How to get the major and minor number of dynamically loaded module.
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1answer
57 views

Appliance with USB port for user storage - how to detect/how to allow unsafe unmounts?

I'm trying to build a simple "appliance"-type device running a minimal Linux and some custom code. Part of the functionality I am offering is that the user can attach a USB flash drive or hard drive ...
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1answer
461 views

The “-zoom” option slows down mplayer

I am working on embedded Linux.(arm) I am using mplayer. In general, the video plays well. (# mplayer aaa.mp4) However, using the "-zoom" option will slow video playback. (# mplayer aaa.mp4 -zoom) ...
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1answer
546 views

Installing rpm packages and resolving dependencies on an embedded device

I got an embedded device with RPM on (no Yum). The way I install packages now is by downloading the proper .rpm file from rpmfind.net and running rpm -i package.rpm. This process repeats for every ...
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376 views

Connecting to embed yocto using minicom text garbage

I am trying to connect over serial cable from ubuntu 12.04 to an embedded linux device for which uname -a returns: Linux demosystem 3.10.17-1.0.0_ga+yocto+ga29b925 #1 SMP Mon Jul 6 21:50:27 PDT 2015 ...
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1answer
363 views

Embedded linux read only

I'm currently working on an embedded linux device, i'm trying to make the file system read only which is fairly easy to do, but the application requires read/write access to files in /etc folder (...
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1answer
237 views

Any way to be notified of EXT4 errors when mounted with “errors=continue”

I am prototyping a new embedded system that uses ext4 on Flash memory. These systems will be remotely deployed with no local sysadmin, so any diagnostics must also be done remotely via a network. ...
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211 views

cups problem with embedded buildroot

I have a embedded linux created with buildroot project. i install cups, cups-filter and ghostscript and configure cupsd.conf file! also i add my hp 1102 printer using cups web interface on port 631. ...
2
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1answer
41 views

Running Application Automatiacally

I am using MPC8323E-RDB development board for Embedded-Linux development for applications. Here, I want to run my application automatically upon boot-up. I tested by changing /etc/inittab file, but ...
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1answer
4k views

U-boot: bad magic number

I'am using Arduino Yun and i want mount rootfs over NFS. I downloaded openwrt sources, build the project and then copied the generated rootfs from build_dir/target-mips_34kc_musl-1.1.15/root-ar71xx ...
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0answers
117 views

Embedded Linux without init.d?

I've recently built a custom Embedded Linux version for my single-board computer using Yocto. But this build is new to me - there are neither /etc/init.d folder, nor /etc/networking/interfaces ...
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28 views

is there difference between running an application from nand and ramdisk?

I'm using an application on an embedded linux platform. I copied this application to a nand device with a jffs2 filesystem and ran it from there and system performance is significantly degraded. I ...
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0answers
30 views

Is it possible to change the clocking for an audio codec from Linux (userland or driver)?

I have an i.MX6 evaluation board with an audio codec from Cirrus Logic (WM8958). The board also supports PTP hardware clocking. Is it somehow possible to change the reference frequency for the audio ...
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0answers
188 views

Device Tree Overlay fragment notifies and loads children twice

I have the following device tree overlay fragment, and when it's loaded, spidev is added twice: fragment@0 { target = <&fpga>; __overlay__ { #address-cells = <1>; ...
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1answer
481 views

How to change password in Linux on Odroid

I have Odroid and Linux on it. I have only these commands: [ hostname mkfs_ext2 rmmod [[ hush mknod route busybox ...
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Boot Linux from Linux on embedded board

I'd like to know, is there a way to boot a new Linux system, from a Linux ? Let me explain : I want to keep 2 systems separated on an embedded board. One system is used to perform tasks at the ...
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1answer
654 views

Multithreaded applications on a single threaded CPU?

The motivation behind this question arises from exploring the Intel Galileo gen2 board which has a single threaded processor. I'm looking for a conceptual explanation on what does that mean for all ...
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2answers
29k views

NFS mount: can't find file in /etc/fstab

I have in hand an Arduino Yun and a Linux Arduino 3.3.8 OS on it, the host machine is Ubuntu 14.04. I'am trying to mount a file in my host machine to the board. I 'am following this tutorial The ...
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1answer
167 views

Override mtdparts after kernel has booted

Information about mtd partitions can be passed to the kernel via the kernel command line (mtdparts parameter) or via the device tree. Is it possible to override this after the kernel has booted?