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

learn more… | top users | synonyms

0
votes
0answers
26 views

Force dirty pages limit in kernel sources

First of all, I'm not sure if that's a solution to my problem. My problem is that during I/O embedded linux is allocating too much memory in cache causing OOM if I run anything else. I/O operations ...
1
vote
1answer
271 views

WIFI over SDIO over USB - Do I have to reflect that in the device tree?

I am currently extending an embedded hardware platform which runs a linux kernel 3.16. I want to connect an external SDIO controller to the USB bus, and then run a WIFI module using that SDIO ...
1
vote
0answers
18 views

Looking for a way to test how often filesystem data is flushed

I have an embedded system, which by it's nature, has power cut off with little warning to the system. The system writes log files to an SD card, and it is desired to have the filesystem flush to ...
0
votes
1answer
3k 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 ...
2
votes
0answers
25 views

Linux kernel hangs at “Starting kernel …”

I have enabled Secure Boot on an embedded device successfully. The problem is that when I am booting in this mode the process seems to get stuck right after the line: Starting kernel ... once U-boot ...
1
vote
0answers
27 views

Embedded Linux OOM - help with lost RAM

I have little Linux system with 256MB RAM. I'm little bit confused, where the RAM may be lost? It is running old linux kernel 2.6.38 and I'm not able to ubgrade it (some specific ARM board). SHM and ...
12
votes
2answers
11k views

How to extract files from uImage?

Buildroot is generating Images for an embedded device where they should run on. This is working very well. In those Images the rootfs is included. Due to some research I'd like to look into that ...
1
vote
0answers
19 views

Add a driver module to embedded linux

I have a task that consists in implementing a driver for an RF module. The RF module communicate with the blackFin609 microcontroller using UART. In a first step i created a uClinux image and ...
0
votes
2answers
58 views

Gap between two characters writing message over RS485

I am using an ATMEL embedded controller (at91sam9x25e) and its serial port to send/receive over RS485 Modbus RTU. Normal communication works fine, but sometimes - when writing - some packages are ...
1
vote
2answers
34 views

How to list the kernel Device Tree

I am using an embedded Arm with a Debian build. How does one list the compiled devices from the device tree? I want to see if a device is already supported. For those reading this, the "Device Tree" ...
4
votes
3answers
28k 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 ...
3
votes
0answers
23 views

Is there a tablet SOC capable of running a blob-free mainline Linux kernel with open wifi, and useable graphics support? [migrated]

I am wondering, whether a platform with these specifications exists: Hacking-friendly from open boot-loader up (support for re-locking?) Linux mainline kernel (blob-free?) boot support with SMP. ...
1
vote
0answers
21 views

DMP 3300MX-A embedded pc, debian 6.0 squeeze, kernel 3.2, bios watchdog and harwdare reset

I have been studying how to properly set up a watchdog on my embedded system, have read plenty of posts, but I am stuck with no solution. I've read: How to correctly configure Debian watchdog daemon ...
3
votes
3answers
2k 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 ...
1
vote
1answer
37 views

How to debug Linux hang?

We are using beagle bone black based custom board, with kernel version 3.12. We are facing system hang during one of the init script,(Which brings up WiFi) this hang happens after random number of ...
1
vote
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 ...
1
vote
1answer
42 views

insmod: cannot insert './intrpt.ko': Function not implemented

I'm writing a kernel module that receives interrupts for mpc8308 (PowerPC) board. when I make the code for Ubuntu and my current version of kernel it works well with interrupt of keyboard, but when I ...
1
vote
0answers
26 views

What happens if I try to use a device driver from the shell and it is already being used by the kernel?

This is the situation. I'm new to embedded linux and I'm trying to test some commands for the LED driver LP5521. The board I have has a RGB LED with this controller IC and it is being initialized with ...
3
votes
2answers
4k views

How to create boot SD card for Banana Pi manually

It seems that I have a lack of understanding how booting SD-Card images on devices like the Banana Pi work. The situation is as follows. I have a Banana Pi and a Banana Pro. Every device has an ...
0
votes
1answer
39 views

Embedded Linux Distribution

I have a small device that runs a light weight embedded linux. I can telnet and ssh to the device. This device has no package management utility on it that I can tell. I am trying to install a pre-...
4
votes
1answer
77 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 ...
0
votes
1answer
36 views

How to “export” configuration variables and “source” them on embedded Linux?

A router runs firmware containing BusyBox and in addition to flash memory the device has secondary memory storage. That USB stick is mounted at both /media/Main and /opt: # mount | grep sda /dev/sda1 ...
1
vote
0answers
52 views

Building kernel for BeagleBone Black lead me hdmi problems

I have successfully followed CLFS book to build RPi and BBB embedded systems. In RPi case the bootloader did not give me problems with device tree. Some years ago I would have to patch Torvalds' ...
4
votes
3answers
115 views

UTC vs. localtime has an offset of about 25 seconds

I have compared this in different systems, but only get this behavior in an embedded system running Arago linux. I use the date command from BusyBox v.1.13.2 I executed this two commands "...
2
votes
3answers
80 views

OpenBSD stripdown

I recently tried to install OpenBSD to my Soekris net4526, but the 64MB onboard memory is too small. Is there any way to make OpenBSD smaller, because even the smallest configuration (bsd and baseXX....
2
votes
1answer
536 views

tty not resizing properly

I'm running an embedded poky linux (linux-yocto v3.13) on a beagleboard. However, I'm having trouble when logging in over a serial using PuTTY: the terminal does not resize at all. Usually, the ...
1
vote
0answers
38 views

Resume from hibernation is not working on embedded linux system

I'm trying to build an embedded linux system based on an Atmel AT91SAM9G25 SoC (ARM9 @ 400Mhz) CPU. I'm using the AT91Bootstrap bootloader. As the subject of my post suggests, I have an issue with ...
0
votes
1answer
31 views

Instantly getting Write Failed: Broken Pipe with SSH to an embedded system

As said above, when I try to SSH into my embedded system (a De0-Nano-SoC FPGA development board running Angström with Kernel 4.1) I get a "Write Failed: Broken Pipe"-Error and get disconnected. I read ...
4
votes
1answer
58 views

Encrypt files (private key, etc.) in an embedded system

I am working on an embedded device running on Linux. This device communicates with a server and sends data to it using a certificate and a private key. When we distribute the device, I am afraid that ...
0
votes
1answer
242 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 ...
0
votes
0answers
35 views

No response to DHCP broadcast

Following on from this question, I'm still trying to get ethernet and DHCP working on a buildroot-based embedded Linux board. Here's what I'm trying: The ethernet interface is brought up using ...
0
votes
1answer
300 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 ...
1
vote
1answer
27 views

ppp affecting serial ports so that they cannot be used if modem is reset

I've got a Buildroot-based embedded system that uses a 3G modem (Cinterion PH8-P) and PPP to connect to the internet. The 3G modem is a USB device that provides 4 ttyUSB ports. One of these is used ...
9
votes
3answers
4k views

What are the minimum root filesystem applications that are required to fully boot linux?

It's a question about user space applications, but hear me out! 3 'applications', so to speak, are required to boot a funcitonal distro of Linux: Bootloader - For embedded typically that's U-Boot, ...
0
votes
1answer
111 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 /armv7l-linux-gnueabi/...
1
vote
0answers
40 views

Add bash to base Linux Kernel?

We have a proprietary SBC (Single Board Computer) type of platform that is a large sized scale Raspberry Pi essentially. It is ARM based and uses Linux Kernel v3.# as its base. This isn't an Ubuntu ...
0
votes
0answers
12 views

is `blockdev --flushbufs /dev/mmcblk0p1"` blocking call?

I am using blockdev --flushbufs /dev/mmcblk0p1 in onf the shell script and would like to know if this command doing blocking call or not? I see it from man page that it is ioctl call to the block ...
0
votes
0answers
15 views

Debian Linux WiFi hardware monitor for embedded applications

I have an embedded linux board that I am using for a mobile robotics platform. This particular board (beaglebone black - Debian Jessie - Kernel 4.1.x) has seen a few issues regarding long-term ...
1
vote
2answers
71 views

Estimate RAM usage information of an embedded device

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 MHz (CPU cycles) ...
3
votes
1answer
271 views

Implement Java/JavaFX on ARM

I am working on ARM Linux. I have found this link that says that JavaFX could work on ARM. I am confused about Embedded Java SE and JavaFx ARM. Do I need to setup a JVM for those or not? I have ...
1
vote
0answers
68 views

Slow SSH connection on embedded platform

I am operating an embedded device running the linux core. I have OpenSHH_4.9p1 installed running in debug mode and trying to establish an SSH connection using PuTTY. After the login screen everything ...
3
votes
1answer
43 views

Meaning and usage of /proc/[pid]/make-if-fail

I am currently developing inside an embedded Linux environment (kernel 3.10.0), and while goofing around in the procfs mount of the system I found that all processes present the following file in ...
2
votes
1answer
158 views

How do I install another distro on a linux DVR

I was fiddling with an old DVR and discovered it had telnet unblocked. So I ran ncrack and after gaining access started looking around. It seems to be running some custom version of Linux. Not many ...
2
votes
2answers
87 views

Minimal Busybox/Linux Installation - Won't Run C

I'm trying my hand at creating a very minimal custom Busybox/Linux distro, a task that is admittedly above my head, but I figured I'd give it a shot. My issue is that whenever I try to run a C program ...
0
votes
1answer
554 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 ...
3
votes
2answers
52 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 ...
1
vote
1answer
49 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 ] ...
6
votes
3answers
1k 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
62 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 ...
2
votes
1answer
121 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, ...