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

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23 views

Piped commands performance in embedded Linux

Recently, we purchased a software solution to integrate into a device we're developing. There's plenty we need to modify and adapt to our needs, so today I was going through part of the code to see ...
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1answer
32 views

not getting full network speed (or even close) of 100 mbps

When I use rsync on large files it shows a download speed of 2.7 MB/s, or around 22Mbps. When I run ethtool on the NIC, here is the output Settings for eth0: Supported ports: [ TP MII ] ...
4
votes
3answers
21k views

How to remount as read-write a specific mount of device?

How to remount as read-write a specific mount of device? (one folder) The file is "Read-only file system", rw-r-r, so it not allow to change permissions. I need to replace that file, then change ...
6
votes
3answers
951 views

Location of the kernel binary (when not in /boot)?

I failed to find the kernel binary in the standard location in /boot. I've also searched the whole file system for vmlinux or bzimage find / -iname vmlin* find / -iname bzimage However, this is an ...
3
votes
1answer
27 views

Wear leveling of SD card because of swap file in embedded linux

I need to enable a swap file on my embedded linux product. The problem is that the file is located on an SD card. At the moment I'm using 15MB swap and about 120MB RAM because of temporary increases ...
3
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3answers
1k views

Adding Buildroot Package

I'm trying to add a package to buildroot, but I'm not having much success. The package I'm trying to add is an autotools package called scew. I've followed the buildroot guidelines about adding ...
2
votes
1answer
52 views

How to readout unused serial pins (RTS, CTS, etc.)?

I have an interface for RS-232 communication. I need this interface for simple communication (no parity bit or flow control → TX, RX and ground) but now I have quite 4 pins unused (RTS, DTR, DCD/DSR, ...
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0answers
28 views

Compare Audio Files

I want to set up a test-system for an embedded board, so I can automatically test both the audio out and the audio in jacks (LO, LI, HP, MIC). So I thought of recording an audio-file (with a sinus, ...
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1answer
2k views

Debian and Systemd: breaking ordering cycle error

I'm a new embedded developer I'm trying to make systemd 37 work with freescale vybrid board (A5 and M4) running on linux-3.0 After boot with some breaking ordering cycle error, I check with ps ...
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1answer
1k views

How to change hard disk spin-down time on my WD MyBook Live?

I have a 2TB Western Digital MyBook Live. It works quite well and provides a web-based administration interface. There is an option to either enable or disable power saving mode, which spins down the ...
0
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1answer
7 views

How to disable autoconf feature of IPv6 usinf interfaces file?

I am using linux 3.2.0. I want to disable autoconf feature of IPv6. For that I have added following lines in /etc/network/interfaces file. iface inet6 eth0 static address <IPv6_address> netmask ...
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4answers
37k views

How to check password with Linux?

I want to check, from the linux command line, if a given cleartext password is the same of a crypted password on a /etc/shadow (I need this to authenticate web users. I'm running an embedded linux.) ...
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1answer
24 views

Where to place application files in embedded linux deployment?

I'm building a control device that runs Debian Jessie on a ARM based Linux SBC. I'm curious what the recommended location is for application files? To date, I've been placing things in a root level ...
0
votes
1answer
35 views

udev disk mount permissions in linux

We would like to set up a customer account on our overo running embedded Angstrom along with ssh so they can log on to retrieve data. uname -a Linux pb014-01 2.6.32 #1 Wed Feb 29 15:17:02 GMT 2012 ...
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0answers
18 views

HDMI TV stick with debian/ubuntu/android with support for Node.JS and Electron

I'm doing a research about available devices to run Electron on embedded device under Linux (debian/ubuntu/android) and I found EZCast. Seller says it is running under Android castrated version so it ...
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0answers
34 views

Embedded Linux- Cross compiling firefox for arm

I am trying to cross compile Firefox (version 39) for Arm. But, I am getting the following error: /firefox-39.0/mozilla-release-849542617a46/build/unix/gold/ld: fatal error ...
4
votes
1answer
499 views

What does this dd command do exactly?

I have an embedded device with this SD card: [root@(none) ~]# busybox fdisk -l Disk /dev/mmcblk0: 3965 MB, 3965190144 bytes 4 heads, 16 sectors/track, 121008 cylinders Units = cylinders of 64 * 512 = ...
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0answers
25 views

pppd “Couldn't get channel number: Input/output error”

I have two USB-serial adapters with a null-modem serial cable between them, similar to this user. I can setup an IP connection easily between two linux (ubuntu) boxes running this pppd command on one ...
0
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1answer
22 views

How to give a custom name to a serial device on connection?

I am working on ROS under Ubuntu 14.04 on an Odroid XU3 (ARM dev board). I connect two USB devices to my dev board which are recognized as ttyACM0 and ttyACM1 according to the time when they are ...
0
votes
1answer
233 views

Trouble changing backlight brightness (/sys/class/backlight folder empty)

I have a small embedded system that I am working on that needs to be able to reduce its brightness for power saving reasons. The screen is connected by LVDS with separate Inverter Power Output ...
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0answers
39 views

Angstrom on beaglebone black, no output on LCD7 module

I've just compiled Angstrom from source: git clone git://github.com/Angstrom-distribution/setup-scripts.git cd setup-scripts ./oebb.sh config beaglebone . environment-angstrom-v2014.12 ...
0
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1answer
49 views

Using dd command to download mtd block

How to use dd command to download mtd block from embedded Linux-based device? # cat /proc/mtd dev: size erasesize name ... mtd3: 003a0000 00010000 "DRTI2" I need download mtd3 block, so dd ...
0
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1answer
25 views

Compress mtdblock with 'tar' before sending it via TFTP

what is proper command compress mtdblock with 'tar' before sending it via TFTP? tftp -l /dev/mtdblock3 -p 192.168.100.40
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vote
1answer
29 views

Managing(adding/deleting,etc) users in a squashfs(RO file system) with a small R/W partition

I'm using squashfs as the file system on a board which is RO, along with a small jffs2 partition which is R/W. The files corresponding to user management, i.e /etc/passwd, /etc/group & /etc/shadow ...
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0answers
49 views

SSH Remote Execution - checking server can do it?

I have a embedded device (Perle IOLAN+, an Ethernet to serial adaptor) that I can administer via SSH. From time to time, I need to log in and execute a command on this device. Logging in via SSH, ...
3
votes
1answer
60 views

High CPU load on the embedded Linux of my router

I hope that, as long as this question refers to Linux, could be answered here: I have a DSL router from Observa Telecom, model BHS-RTA : Modem Name : BHS_RTA Serial Number : D861940E5088 Time and ...
3
votes
1answer
526 views

ERROR: image is not a fdt - must RESET the board to recover

I am attempting to boot the freescale 1040RDB and am having some difficulty. I'm using a pre-built SDK from Freescale that has a linux VB image with the yocto installation along with all of the yocto ...
0
votes
1answer
44 views

Embedded Linux and Init problem - Init won't start

I'm working on a embedded system. I have multiple SD cards to save copy of Linux rootfs on (kernel saved in nand). On a original SD card, where is located a system, and from this card the system is ...
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0answers
32 views

TFTP error when downloading larger files

Embedded Linux device, with BusyBox v1.4.2 multi-call binary. I tried download files from remote device to local computer via TFTP, but got some issue: it works OK for small files (about ~350MB), but ...
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0answers
56 views

Untar a filesystem to device as normal user but maintaining the correct UID and GID

I'm doing quite a bit of development using Yocto to target an embedded system. As its final output, Yocto generates a tarball of the filesystem, which I then untar onto an ext4 partition of an SD ...
0
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1answer
17 views

Listing a file with strange characters on DD-WRT embedded Linux

When SSHing into my DD-WRT router (Buffalo WHR-HP-G54) with embedded Linux to browse the DHCP Lease list I get strange characters: ~ # more /tmp/udhcpd.leases x▒_▒▒ ▒▒iPhone-de-Tomaz▒ ...
0
votes
1answer
40 views

Embedded linux hotplug changed mount point

I have a linux media player that was very common before android's age. It is a MIPS running Linux Venus 2.6.12.6 and has 2 sata, 2 usb and 1 sdcard port. Since the flash memory is very limited, I ...
5
votes
1answer
74 views

Applying device tree overlay

I have a device based on imx233-Olinuxino-Nano. The Arch Linux Arm distro boots and works. However, there is a slave device on my board that is connected to SPI of CPU. It is supported by kernel, ...
0
votes
1answer
77 views

Linux/Embedded Linux - Understanding the Kernel and additional BSP specific components [closed]

*tldr; I would like to generally understand how the world of linux / embedded linux works. What do I need to do to take the Linux mainline and compile/deploy it on a board with different processors ...
2
votes
3answers
7k views

using cross-compiled Valgrind

I have downloaded the sources from the Valgrind trunk and built it for using on an embedded Linux system(Montavista Linux) powered by an ARM926(ARMv5t architecture). Everything went well until I tried ...
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0answers
61 views

sfdisk doesn't work anymore?

I updated my OS to Ubuntu GNOME 15.10 but now I have a huge issue : sfdisk doesn't work! I really need it to build partitions on my SD cards for an embedded Linux but it seems that the options ...
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0answers
20 views

Best small distro for ROM burning of the system for an embedded system

I am building a specific device and I would like to know what Linux based small distribution would be good when I would choose the put-Linux-on-the-ROM route, so, that the system is not possible to ...
3
votes
1answer
64 views

Systemd Boot Optimization dev-mmcblk0p2.device

I'm working on an embedded system and want to make it boot faster. I already stripped a lot of things. Now I don't know how to improve it further. Here is my systemd-analyze blame: 4.457s ...
4
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0answers
38 views

Block device naming, how to enable by-name and by-uuid?

While building and using linux kernel for custom boards, when Android is used, usually the MMC partitions appear in /dev/block/mmcblkXpY. And there are also symbolic links created in ...
5
votes
2answers
2k views

Mount zip file as a read-only filesystem

I am looking for a way to mount a ZIP archive as a filesystem so that I can transparently access files within the archive. I only need read access -- the ZIP will not be modified. RAM consumption is ...
3
votes
0answers
39 views

How best to enable end-user configuration of wifi or Ethernet on embedded device?

I'm building a device that includes an embedded Linux computer and I need to allow the device user to (easily) configure the device to connect to their wired or wireless network. I know there are ...
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0answers
14 views

configure analogic pin as digital pin

I have the SAMA5D3 Xplained. This kit has several analog ports and my idea is to be configured as analog or digital as needed. Would it be possible to do it in an easy way from the kernel? ...
1
vote
1answer
123 views

CLFS for ARMv7 neon

I am following CLFS book (GIT-20140613-arm version), and I have a issue when building GCC with armv7 and neon combination. Target info here. My host is a clean Debian 8 with gawk, build-essential, ...
2
votes
3answers
5k views

tftpput in U-Boot: error: 'Access violation' (2)

I have enabled CONFIG_CMD_TFTPPUT in U-Boot, but I am not able to use it. I have set the serverip and ipaddr environment variables. When I use it as follows, it times out: u-boot# tftpput ...
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0answers
34 views

There is possible to read 1-wire (ds18b20) without waiting for conversion?

I want to read temperature value from ds18b20 by 1-wire interface without blocking. There is any way to do that? I tried fnctl(fd, F_SETFL, O_NONBLOCK) but its not working. Actually I have a loop ...
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0answers
34 views

Is there some way of simulating a framebuffer device?

I'm starting to write a small software that I intend to run on embedded linux, and I want to draw the GUI using a framebuffer device. However, since I want to be able to test the software on my ...
0
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0answers
166 views

kernel panic not syncing: vfs :unable to mount root fs on unknown block(31,1)

I am trying to boot linux from flash on an powerpc board. In u-boot I set bootargs with: setenv bootargs root=/dev/mtdblock1 rootfstype=ext2 rw console=ttyS0,115200 ramdisk_image=\${rd_size} I also ...
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3answers
1k views

How to reduce ncurses terminfo size

I notice that ncurses's terminfo database on /usr/share/terminfo is about 7MB (I compiled it myself). This is too large if I want to deploy it on an embedded Linux of 64MB disk space. Is there a way ...
0
votes
2answers
132 views

gdb installation in beaglebone black with customized linux kernel

I am developing an application for the beaglebone black which I cross compile using arm gcc compiler then port on the compiled binary file to the beaglebone black using scp command and run there on ...
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2answers
549 views

Could not mount UBIFS on SD card

I guess this is not a big problem, still I can't see what's the matter. I'm building Images for an Embedded Linux (2.6.39) ARM9 System with Buildroot 2013.11, which is booting from an SD card. I was ...