1
vote
1answer
39 views

How to download original ramdisk file to the computer? [closed]

Linux embedded, is it possible to download original ramdisk file to the computer, to get source code? Access via SFTP. U-boot 1.2.0 Kernel command line: root=/dev/mtdblock3 ...
2
votes
2answers
58 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 ...
1
vote
1answer
81 views

Canot remove symlinks: after reboot, symlinks re-appear

Using ssh from BusyBox, I cannot remove symlinks: after rebooting the device, symlinks re-appear. ls -la shows that symlinks have been removed, but after rebooting device they re-appear again. Those ...
0
votes
0answers
18 views

Can't access GPIOs when switching to systemd, but why?

I'm using this ARM AT91 Sam9x5ek Embedded Device, with my Linux Images made by a Buildroot. Usually my init-system is Busybox, now I changed it to systemd. Since then I can't access the GPIO anymore, ...
1
vote
1answer
44 views

How to check my account on embedded linux without “/etc/passwd”?

On some embedded linux systems, there is no /etc/passwd file and /etc directory is not writable (which means I cannot set user account and password?). Then what is my (default) account name and ...
0
votes
1answer
52 views

How to know free disk size witout df command? [closed]

Is it possible to check free disk size in Linux without using command lines such as df? Since my host machine is embedded Linux, there are no direct command lines that show free disk size.
3
votes
0answers
49 views

Why is my swap not being activated automatically via fstab?

I've got a Linux embedded system that I'm experimenting with (the Elektor Embedded Linux Made Easy board, based on the GNUBLIN http://en.gnublin.org/index.php/GNUBLIN-Elektor). I'm using the 3.3 ...
1
vote
0answers
33 views

How do I know from a BeagleBone Black if it is connected via USB (as a client/slave)?

BeagleBone Black has an USB port which allows the user to access it through ssh. In general, we could say that when you plug it to a PC, the PC is the USB host and the BBB is the USB client. On the ...
1
vote
0answers
34 views

Is there a limit of GPIOs that can be used in Linux?

When it comes to use GPIOs, is there a limited number that can be used in Linux (except through the limitation of the physical availability/amount of the ports/pins) or is it theoretically possible to ...
1
vote
1answer
92 views

Why isn't sda1 showing up in dev and how can I fix that?

I have an embedded Linux device and I was trying to copy some files to it. I plugged in a USB stick, the dmesg shows that it was recognized, but for some reason /dev/sda1 never showed up. I'm trying ...
4
votes
1answer
26 views

How do you ensure physical network interfaces always get the same interface name across reboots on an embedded Linux system?

For an embedded Linux system, if I have two or more network interfaces, how do I ensure that they always get the same interface names every boot In other words, I want, for example, eth0 to always ...
6
votes
3answers
83 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
2answers
102 views

Kernel does not skip bad blocks when mounting filesystem

I am developing for an embedded Linux application using friendlyARM's micro2440. It runs on a Samsung s3c2440 ARM processor and uses squashfs in its NAND flash. Recently, some flash blocks went bad. ...
2
votes
1answer
116 views

How configurable is MPTCP?

I work on embedded Linux devices that usually have hard wired Ethernet as well as cell modem connections. If I were to use MPTCP would it be possible to easily configure the system to use eth0 all ...
1
vote
2answers
66 views

live dd over a mounted read-only root partiton

I'm trying to conceive a firmware update mechanism for a Linux-based embedded system without an additional initrd/initramfs/whatever. From within the running system which has a read-only mounted root ...
1
vote
0answers
34 views

Get log from kernel while loading

There is a arm/omap2-based device without ethernet, UART ports. It has usb connection with host, numeric keyaboard, LCD display. There is working U-Boot and kernel images for this. I'm trying to ...
16
votes
3answers
72 views

Can I achieve functionality similar to interrupts in Linux userspace?

One of functionalities I miss the most from "small embedded" in Embedded Linux is the interrupts. A signal appears on a specific pin, or other interrupt source is triggered and whatever was done ...
13
votes
4answers
154 views

Corruption-proof SD card filesystem for embedded Linux?

Recently we had a rather unpleasant situation with our customer - Raspberry Pi based "kiosk" used to display remote sensing data (nothing more fancy than a kiosk mode browser displaying a ...
3
votes
1answer
396 views

Which TCP congestion control algorithm is best for low speed radio modems?

On my project we have remote Linux nodes that communicate over the Internet via very low speed CDMA cell modems. The bandwidth on these modems is about 2kbyte/second and the RTT back to the server is ...
1
vote
0answers
42 views

Removed USB storage device is still mounted

I'm working on a embedded linux system based on busybox. Sometimes a USB device which is physically removed from the post is still displayed in mount, df or /proc/mounts. If I reattach the device, it ...
1
vote
2answers
80 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 ...
1
vote
1answer
60 views

WARNING: at kernel/irq/handle.c - after changing rootfs, but why?

today I changed from an image with initramfs to an image with separate kernel and rootfs. Theses images are used for an Embedded System (ARM9 SAM9G25), that is runnging with an Linux 2.6.39. During ...
1
vote
1answer
51 views

Uninstall Linux on an embedded board

I am using an embedded board, a FOX G20 V with an ATMEL AT91SAM9G20 processor. I would like to know first of all, which specific linux version I am using on this board, but also, how to remove it. ...
0
votes
1answer
468 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 ...
1
vote
0answers
63 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
70 views

Interfacing ds1337 RTC on LPC17xx

I am a newbie and I am trying to understand how to interface DS1337(RTC) on LPC17xx Board. This board uses uclinux 2.6.33. .CONFIG: CONFIG_RTC_LIB=y CONFIG_RTC_CLASS=y CONFIG_RTC_HCTOSYS=y ...
3
votes
2answers
214 views

File system that never breaks (data loss acceptable)

There're several existing topics revolving around this issue, but what I seek is slightly different. I have an sd card on an embedded Linux and it suffers from power loss. I might be able to modify ...
1
vote
0answers
78 views

Why is my embedded Linux unable to detect the sd device?

I have this ARM9 SAM9G25 embedded System, running a Linux 2.6.39 Kernel and a Busybox. I put the Images (of the bootloaders, and the linux+initramfs) on a SD so that in the end the system is booting ...
3
votes
1answer
53 views

How to determine how many bytes / hr are being written to my SD card

I have a Debian embedded Linux system that uses an SD card as the RFS. What is a reliable way to determine how many bytes / hr are being written to the SD card?
3
votes
1answer
181 views

How to set the CPU freq. in Linux?

I'm using this ARM9 SAM9G25 embedded system, that when switched on, is only online for a few seconds and because I want to speed up the whole process, I'd like to check the CPU frequency, and set it ...
0
votes
1answer
86 views

supported 2014 distro with 2.6.x kernel

I'm cutting my teeth at putting together a Linux install for a PC104 board that supports <= kernel 2.6.x with a Disk-On-Chip. I've read up on Embedded.org and Yocto, but before I try compiling ...
1
vote
1answer
225 views

High RX packet error count with modem - how to analyze?

I'm testing a CDMA modem on my Debian embedded Linux system. I'm doing some wgets of large files and am seeing the connection drop now and then. Looking at the ifconfig output for the PPP interface ...
0
votes
1answer
303 views

Basic script in Angstrom Linux running on a Beaglebone Black

On my embedded system, I can toggle a user led with: echo > 1 sys/class/leds/beaglebone:green:usr2/value. Similarly, I can find the value of a GPIO (gpio60) (set to input), with more ...
2
votes
1answer
138 views

How to build a basic embedded linux on a Qualcomm router?

Not knowing the first thing on how to build a minimal linux system on an embedded device, I'd like to get some pointers in the right direction. Generally speaking, I'd like to know what are the ...
1
vote
1answer
140 views

How to make a USB storage device undetectable in u-boot?

I need to do a test in an embedded system where I plug in the USB storage device and do "usb start" but the USB storage device is not detected. I have a working pendrive. How to make it undetectable ...
4
votes
1answer
239 views

How do I load initrd into memory to be passed to kernel when using kexec?

As the MIPS port of kexec doesn't support the --initrd param, I'm looking for workarounds to imitate the feature. According to Linux/MIPS wiki, MIPS kernels support rd_start and rd_size kernel command ...
0
votes
1answer
297 views

how do I include the qcserial module in the kernel?

I need a kernel compiled, featuring the qcserial module to have support for the Huawei EM 680 model (Gobi 3000). I got kernel 3.11.6 and can find the appropriate source file in ...
3
votes
0answers
110 views

What is the difference between the output of TOP command and Oprofile?

In the top command one of the processes is always showing a CPU usage of 4 to 5%. But in oprofile the CPU usage is 0.004%. I do not understand this. And I also noticed that even when a process is in ...
3
votes
0answers
30 views

Queuing disciplines are per-interface, what happen with interfaces using same device?

I have read about queuing disciplines here http://lartc.org/. I understand that for instance band 0 of pfifo policy is prioritized over band 2 within same qdisc, but what happen when i have ppp0 and ...
1
vote
1answer
789 views

/dev/console dynamic redirection

Is it possible to dynamically redirect all data sent to /dev/console into something else (for example - to /dev/null, /dev/tty9 or even /dev/null)? Of course, it can be done statically via ...
0
votes
2answers
85 views

embedded linux and powering usb stick

I have a problem where I need to read a usb-stick or a usb keyboard: When I plug in the USB stick or keyboard I can't get power to the device. dmesg says nothing I tried: for device in $(ls ...
6
votes
2answers
855 views

Is it possible for a daemon (i.e. background) process to look for key-presses from a USB keyboard?

I'm working on an embedded Linux project where I will be developing a program that will run automatically on bootup and interact with the user via a character display and some sort of button array. ...
2
votes
1answer
476 views

What is the easiest way to draw graphics on Linux framebuffer?

I have some embedded Linux ARM chip with LCD display on frame-buffer. I connect to chip with serial console. I can access frame-buffer directly with low-level commands. However I need to draw some ...
1
vote
1answer
380 views

mmcqd hangs and burns the CPU on the embedded device

On my embedded system I'm writing an intensive video stream to SD. I don't mount partitions, just write to /dev/mmcblk0p1. After a while my writing process hangs. I get [16952.240000] INFO: task ...
1
vote
1answer
547 views

How to configure linux to output to monitor

I'm currently running a lightweight Debian distro on a development board from Compulab. I have to login to the system via serial port everytime. The system has graphical card and the driver is ...
1
vote
1answer
178 views

can linux be configured to blink an LED (GPIO) on disk activity?

I'm hoping to blink an LED that is wired up to a GPIO line whenever the USB connected disk has activity is there an easy way to pull this off?
1
vote
0answers
97 views

Data loss prevention ( or recovery) in a MySql db in embedded systems

I have a little ( big ) problem with a MySql application that write on a SD card or a Compact Flash. After a data loss ( a power failure , for example) , if I try to retrieve the data of my db , it ...
1
vote
0answers
101 views

Are there any good Embedded Linux image builder? [closed]

I'm looking for an image builder to create several Embedded Linux images for different ARM boards. I know the following image builder: linaro, buildroot, openEmbedded, yocto If I've missed one, ...
1
vote
2answers
1k views

Why is my wlan0 interface on Angstrom (Beagleboard) “Not Associated”?

I'm installing a Angstrom (custom build, not the default build) on a Beagleboard XM. I can scan for wireless networks using iwlist and see the neighborhood wireless devices. I have set my SSID and ...
1
vote
1answer
184 views

compressed and uncompressed kernel on an embedded device

I have been using several different embedded boards that store kernel, init files, filesystem, etc. on partitions of a (micro)SD card. I notice in the example usage or instructions that compressed ...