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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Cant hide mouse cursor on embedded Debian
I am working on a Debian-based Dragon Board (410C) system. The system will produce a touch screen that triggers some functions of a car. I am trying to hide the mouse cursor in my application. ...
1
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1answer
21 views
How to manually mount the virtual file systems, to copy MTD partitions
Linux version 2.6.26.5, ARM Linux Kernel on embedded device, NAND-based device. I'm at Busybox rescue shell (ash), with restricted command set.
How to manually mount the virtual file systems, to copy ...
1
vote
1answer
14 views
Run script after module is loaded due to device tree
Why do I want this?
I use the pwm-ir-tx kernel module to blast IR signals from my embedded device. However, when the pwm kernel module is loaded during the boot process, the pin is on high. It takes ...
1
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0answers
40 views
Backup MTD partitions on NAND flash use 'nanddump'
Linux version 2.6.26.5 om embedded board, at boot time created 11 MTD partitions on "gen_nand":
# cat /proc/mtd
dev: size erasesize name
mtd0: 00060000 00004000 "u-boot"
mtd1: 00020000 00004000 "...
1
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0answers
28 views
How can I run a script on a Unix box without enough space to store it?
Specifically what I'd like to do is run screenfetch on my router, just for fun.
Here's my disk space free:
admin@RT-N66W:/tmp/home/root# df
Filesystem 1K-blocks Used Available Use% ...
0
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1answer
22 views
Replacing busybox in an embedded device
I'm using busybox in an embedded device. The built-in busybox is rather limited.
So I want try to replace busybox in place with new, more complete version. I find some info about replacing Busybox on ...
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0answers
31 views
How to configure embedded linux kernel so that the file system is visible on the host linux
I am using a powerpc, and after building and flashing the linux kernel on the device I can see the file system. But if I try to create a user or make any changes they get erased and resets to default ...
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0answers
26 views
How to use embedded device as bluetooth HSP/HFP source
I have ARM based board, kernel 4.14.67 and bluez-4.101. I want to connect bluetooth headset for playing sound from the board. My question is similar to that: https://stackoverflow.com/questions/...
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0answers
22 views
UBI layout volume not found
I am following Bootlin's embedded Linux training which aims to put an embedded Linux system on an Atmel SAMA5D4 Xplained board (theory slides, practical lab instructions) and I am stuck a putting the ...
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0answers
45 views
Reading and writing NAND flash with dd
I have an embedded device and I'd like to backup the NAND flash.
From the openwrt wiki I gathered that dd is not a suitable option for dumping. You can use dd, but the dump will be garbled. However, ...
0
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1answer
27 views
How investigate sporadic restarts
The system is :
Debian 8.1 run on embedded system with ARM7V CPU 2 GB RAM and 4 GB flash.
The system sporadically restart itself couple time in day, before a week with appear very rare.
What is the ...
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1answer
38 views
How to read back a fan speed?
I am on a custom board using an i.MX6. I am using Yocto (Pyro) to build my kernel (4.14.16).
I am using the generic imx6qdl.dtsi device tree entry for PWM2 to drive the fan and it appears to work ...
2
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3answers
21 views
Are there any current videostream-player-type 32-bit distros in 2019?
I have these thin clients that are not in use I think they’d do perfect for a security camera video wall—just feed them an RTSP/RTMP URL and be done, GUI not needed.
I’ve been lazily looking for ...
1
vote
2answers
102 views
Embedded Linux: setting the time without NTP
Working on a embedded Linux device built using yocto that is pulling a date via uart from another device with a satellite connection. By the time we have access to this date, we are well into a fully ...
0
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1answer
58 views
Asterisks locks ALSA device if chan_alsa is loaded
I am implementing an extension 900 which routes the audio to ALSA device.
I am also using mpd, which plays music through ALSA.
Asterisk 15, OpenWrt 18.06
mpd.conf:
log_file "syslog"
...
2
votes
1answer
106 views
Get video device on embedded Linux SoC
I'm trying to find the camera module device of an IP camera (running Linux), without much success.
My main objective is to find the camera stream, so I can attach an RTSP server.
Update 26/02/2019
...
1
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1answer
57 views
Optimal sharing of a ring buffer between processes
We're implementing an embedded Linux system and have to provide a live updating graph on a website that shows data coming from a background process in the system.
The question is how to optimally ...
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0answers
37 views
How to tell Linux where initramfs is in RAM
I'm trying to boot a Linux kernel running on top of Xen with a initramfs copied into RAM by the bootloader.
In the device tree I took out a chunk of memory so the kernel will not overwrite the area ...
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0answers
32 views
Cannot Reach External Network Despite DHCP on QEMU Embedded Guest
I am trying to give an embedded router networking on QEMU. I replaced the router's kernel and modules using a generic buildroot build for the Malta CPU. I also can compile any software needed to help ...
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0answers
12 views
How deep is U-Boot's `bootm` command checking for a valid header?
TL;DR: How many ways can the bootm command fail with this error in version 1.1.4?:
# bootm
Booting image at 31000000
Bad Magic Number
Background:
I've bricked a device whose U-Boot is deeply ...
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0answers
44 views
How do I rearrange the clock tree to get the clock I need?
I am using a LVDS display on an i.MX6 DualLite. The panel is supposed to be running at a clock of 51.2MHz. I am in the process of updating to a newer Yocto (Pyro) built BSP running 4.14.16. The ...
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0answers
47 views
Import value from kernel startup code to user space
I need access to a variable, an integer, whose value is determined during startup on this embedded system.
The kernel is: 2.6.35.14 and the variable I am trying to access is created an used in the ...
1
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0answers
22 views
Is it possible to access linux/ramdisk code memory from its running system?
I'm working with an embedded Linux device that has to be auditioned by a regulatory agency.
The agency will select a few devices in the field to check if the code running is the same as auditioned.
...
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1answer
79 views
resolv.conf always empty
I have 2 different embedded devices...an old one running TI arago Linux and a Xilinx device (petalinux).
On both I see the same outcome when adding dns-nameservers to /etc/network/interfaces and ...
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1answer
51 views
Interpreting /proc/partitions
I'm confused about the partitions size of a flash memory in my embedded linux device:
/ # cat /proc/partitions
major minor #blocks name
240 0 93184 ndda
240 1 85168 ndda1
...
1
vote
1answer
31 views
JTAG'ing firmware into imx28
My goal here is to load a custom kernel and initramfs into the memory of the wink hub 1 based on imx28 dev board and boot it using the bootm command from u-boot shell.
So, I downloaded the u-boot ...
0
votes
1answer
136 views
Flashing U-boot on beaglebone black
I got a beaglebone black which comes with u-boot linux preinstalled on the emmc. For the sake of learning I want to put u-boot on the flash myself and build linux from scratch. I have compiled u-boot, ...
1
vote
0answers
20 views
Embedded Linux: Setting up NFS (or any service) in a portable way
If I have a read-only file system, but with a read-write overlay on /etc, is it possible to run NFS service (or any other service) via a USB drive, as if the service is a portable application?
Note: ...
1
vote
2answers
111 views
Rootfs versus kernel confusion [closed]
I know that they are two different entities. Rootfs is a file system which describes how to store and access data. The kernel is actual code which executes.
However, isn't the kernel code stored ...
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0answers
114 views
How to bitbake copy a prebuilt static library into the sdk
Scenario:
I am working with yocto linux recipes. I am trying to make a recipe which simply copies a prebuilt MyLibrary.a and its headers available on the built linux image. So, I have a libMyLibrary.a ...
0
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1answer
184 views
mmc0 warning on SD card bootup of linux
I get the following warning on debian linux (kernel 4.18.8) bootup of my microchip sama5d3 board:
mmc0: unrecognised SCR structure version 4
mmc0: error -22 whilst initialising SD card
after spewing ...
1
vote
1answer
54 views
SD card issue in embedded linux
My setup: Embedded linux version 3.x on an ARM board with a SD card.
After running for a couple of months, I am getting this print in the console.
I want to understand this issue, and fix it.
...
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vote
0answers
27 views
How do I shrink a partition from the beginning? i.e. create empty space at the beginning of the block device?
I have devices with SD cards, with several partitions. The first partitions on the card is typically not mounted, and have vfat filesystem.
What I want to achieve is, to create a 1MB free space just ...
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0answers
96 views
login system on a buildroot linux router [closed]
I have a Gemtek WVRTM 127ACN router / modem, If you do not touch any key during startup, linux starts automatically. It's a linux version created with buildroot, the problem is that there is not a ...
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0answers
25 views
How to check the history of processes
I'm using Debian running on a BeagleBone Black. I have a script which is supposed to execute when the system starts. The script then should run a python script. I add the command to run this script ...
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0answers
16 views
integrity check of uboot using dd
I just upgraded uboot using dd and it boot successfully :
dd if=uboot_file of=/dev/mmcblk0 bs=512
The output is :
1360+1 records in
1360+1 records out
I would like to read backup to ensure every ...
0
votes
1answer
93 views
How much space does my Debian OS need
I am using a BeagleBone, with 4GB of internal emmc.
When I install a Debian image on it from its site and run command df -h , the result is below. /dev/mmcblk1p1 shows that it uses 3.4G of memory. ...
0
votes
1answer
29 views
nc server does not work if launched on startup
I wrote a (ba)sh script to write to a file the content received from a POST method:
#!/bin/sh
PORT=$1
FILE=$2
while true
do
echo -e "HTTP/1.1 200 OK\n\n" | ./busybox-armv7l nc -l -p $PORT | tr '[\...
0
votes
1answer
245 views
Could not find libmount
During compilation of customized distribution (using buildroot v. 11.2018)
I have problem with libmount library (the problem appeared after I had included efl package in buildroot menuconfig - Target ...
1
vote
1answer
124 views
Install python on an embedded device
I'm working on an embedded device already customized. Here some details:
# uname -a
Linux DX-4400 3.10.31-ltsi-05172-g28bac3e-dirty #12 SMP Tue Jan 23 17:14:13 EST 2018 armv7l GNU/Linux
I have root ...
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votes
0answers
40 views
What baud rate should I set when using screen tty for bluetooth?
I'm paired up with an Xbox Controller and want to see the output coming from the xbox controller in order to figure out its protocol.
I'm trying to do screen tty.Bluetooth-Incoming-Port 9600 on my ...
1
vote
0answers
9 views
DBus Transport - force transport to idle state from Bluez5 embedded side - A2DP [closed]
I'd like to be able to force Bluez's transport state from active to idle on the rendering side of a custom embedded platform. This issue is centred around the fact that simply pausing the A2DP ...
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votes
1answer
57 views
What are the Hardware requirement for Debian Linux Kernel 3.16 for PPC architecture? [closed]
We have an Embedded System which is running on Debian Linux Kernel 2.6-2.6 [PowerPC Architecture]. Would like to upgrade the Kernel to 3.16.
What are Hardware Requirements?
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2answers
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How to make /var/log persistent through reboots on an embedded linux device
Scenario
I am on an embedded linux system. As usual /var/log/ is the directory when all the logs are stored. I have a directory called /safepath which is created during image creation and it is on ...
3
votes
2answers
713 views
Reduce Boot time
I would be interested in finding ways to reduce the boot time, specially in embedded-related environments.
I've read somewhere of a method to avoid the kernel to load some drivers or modules but I'm ...
0
votes
1answer
31 views
Need to switch debian FS readonly writable layer from tmpfs to aufs to not lose files after booting
I'm trying to have this done on a debian 9 based embedded system. The fs that come for root is mounted as such in /etc/fstab:
# /etc/fstab: static file system information.
#
/dev/mmcblk1p1 / ext4 ...
1
vote
1answer
61 views
IP Camera with embedded Linux won't connect to internet using ethernet
I have an IP Camera from Thundersoft with a Qualcomm Snapdragon 625 chip inside that runs a Linux distribution. It is extremely limited in terms of available commands, and I can't install any new ...
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votes
0answers
35 views
Why “receive / transmit bytes” is so big difference between optical modem and host when download data on host?
ens33 is my host network card,it show a normal number as my network use status,but I don't know why my modem show a very small data traffic in all interfaces of modem when download on host.
My host:
...
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0answers
150 views
udev: how to wait for a specific device to appear from a shell script
I have an embedded system with a tiny initramfs which needs to mount an overlayfs over the rootfs partition and switch_root to the new merged filesystem.
It's just a couple operations run from the ...
4
votes
1answer
132 views
gunzip on Embedded machine
I'm using BusyBox 1.24.1 on my Embedded Linux machine (with kernel v3.10.31) and I get behavior I can't understand when unzipping files.
The gunzip command (often, but not always) fails,
with no ...
