The use of Unix in embedded computer systems such as networking equipment, mobile phones, media players, set-top boxes, etc.
3
votes
1answer
30 views
Embedded Linux: Which machine directory to pick in /arch/arm?
I am just starting out with embedded Android drivers, so any help would be great. I haven't found a lot of resources online.
At the moment, I am working through a tutorial on porting a driver, and ...
0
votes
3answers
41 views
How can I add a script to embedded Linux
I have a script (let's say Hello World), that I want to include to my embedded Linux. I'm using Buildroot and want to start the script in Busybox. But because I'm cross-compiling for the target I'm ...
0
votes
1answer
70 views
Change the root filesystem on an embedded system
I'm using Buildroot to generate an embedded Linux with a kernel v. 2.6.39, which in the end starts busybox. Everything works fine when building with Initramfs as "rootfs". But Initramfs isn't the best ...
2
votes
1answer
51 views
upgrade Python to 2.7.2
I have an embedded system running on Python 2.6.5 and i want it to upgrade to 2.7.2 (I have a running system with different kernel that runs 2.7.2). I have copied the binary but then it told me: ...
2
votes
1answer
39 views
Transparent Ethernet over GRE not forwarding traffic
I am running on Linux 2.6.30.9 and have been trying to setup a transparent ethernet over GRE tunnel. The network topology used is as follows:
I want to bridge PC1 and PC2 using Transparent Ethernet ...
2
votes
1answer
55 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
47 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 ...
1
vote
0answers
45 views
Log files corrupted with NUL characters and text from other processes
I am running Wind River Linux 4.3 on an embedded Freescale single board computer (SBC). Output from uname -a:
Linux ge101 2.6.34.10-myname-grsec-WR4.3.0.0_cgl #1 SMP PREEMPT Mon Aug 26 01:35:35 PDT ...
0
votes
2answers
30 views
GRE supported in kernel but iproute2 cant create GRE tunnel
Im trying to create IP over GRE tunnel but i get No such device:
ip tunnel add gre0 mode gre remote 192.168.152.22 local 192.168.152.21 ttl 255
ioctl: No such device
I have compiled GRE support in ...
3
votes
0answers
72 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
59 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 ...
6
votes
2answers
53 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 ...
1
vote
0answers
32 views
App consumes diferent %CPU if started at start-up or from prompt [closed]
I run an application in embedded system, and it needs to start at boot. However, I have a problem with it: when I execute it at boot (from rc.local script), it consumes nearly all the CPU, making the ...
3
votes
1answer
48 views
Wget download file ( do not overwrite ) auto update script
I want to write auto update script for my embedded device, which can check and download newer version of my program and extract the files on the device.
The download center is hosted on remote web ...
3
votes
0answers
60 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 ...
2
votes
1answer
90 views
Which system calls could create a new process?
When executing ps command in my Linux system i see some user processes twice (different PID...). I wonder if they are new processes or threads of the same process. I know some functions in standard C ...
0
votes
0answers
23 views
What could keep a process in 'Runnable' state indefinitely?
I am developing for embedded Linux and I have found a critical bug when stability test is performed. After 1-3 days running at some points the system becomes inoperative. Kernel network stack keep ...
3
votes
0answers
19 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
34 views
Having several qdisc for each device, which is the first to process?
I have read about queuing disciplines here http://lartc.org/. Having this traffic shaping policy:
....
qdisc pfifo_fast 0: dev ppp0 root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc ...
0
votes
0answers
60 views
optimizing Debian wheezy for an embedded board
I have Debian 7.1 on an embedded board that I just use WiFi interface, openVPN, and run a C code. The code uses UDP socket to transfer data, and do some calculations and output some signal on GPIO.
...
0
votes
0answers
61 views
prioritize traffic for some bridge interfaces using prio qdisc
Im configuring my router to give preference to some WAN interfaces. This interfaces are named ppp0 (PPP interface), vc2 (RFC1483 bridge interface) and vc3 (RFC1483 bridge interface).
I had understood ...
0
votes
0answers
46 views
how to enable java support to buildroot
I'm using buildroot 2012.08 version for building embedded linux. I'm looking for best solution to add java support. Is it possible to do trough buildroot?
0
votes
1answer
76 views
What could cause a run time remounting of my /var partition to be read only?
I have a buildroot generated embedded linux system (x-86 geode processor) using an initramfs but with /var and /etc mounted onto a compact flash device using the default mount options specified in ...
1
vote
1answer
338 views
What does ifup do when “/etc/network/interfaces” has an invalid netmask address?
The interfaces file looks like below:
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.0.130
netmask 250.255.255.0
gateway 192.168.0.254
As you can see ...
1
vote
1answer
176 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
57 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 ...
0
votes
0answers
38 views
Creating JFFS2 image
I am working on Embedded Linux, trying to create JFFS2 file system in the host and trying to load it on a NAND device in the target board - Olinuxino a13 wifi using Livesuite. I successfully created a ...
4
votes
1answer
151 views
ttyS1/uart1 initialised but not accessible through /dev/ttyS1
I'm not sure at which level I am having a problem.
System is a LeopardBoard DM368 running TI's own SDK / LSP / BusyBox kernel, the core Linux kernel is 2.6.x so using serial_core.c driver model.
By ...
2
votes
1answer
103 views
Know when a memory address is aligned or unaligned
Im getting kernel oops because ppp driver is trying to access to unaligned address (there is a pointer pointing to unaligned address). Im not sure about the meaning of unaligned address. It means not ...
5
votes
2answers
252 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
206 views
How to custom build debian's busybox?
I'm building an embedded system based on debian 7, and I'd like to make the most out of busybox that comes with debian. The problem is default busybox build in debian seems quite minimal, for example ...
1
vote
1answer
173 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
164 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 ...
0
votes
1answer
22 views
Adding access to PPP
I have a PPP connection over USB (dev ppp0), and an eth0 connection. My Linux box has IP 192.168.1.1, I have a second Windows PC with an IP of 192.168.1.3. The ppp conection is 192.168.1.2 - which is ...
1
vote
1answer
130 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 ...
0
votes
0answers
71 views
Compiling a simple character device driver as a module
I wrote a simple character device driver & wanted to cross-compile it for craneboard (ARM architecture). My file name is gDev.c. I copied the file to kernel/drivers/char directory in craneboard ...
0
votes
0answers
66 views
Changing Android files in root directory
Does anyone know how (if it is possible) to change Android files stored in root directory, particularly logo.rle? I want to change my boot splashscreen, changing the file, which is stored in /. I have ...
1
vote
1answer
106 views
How enable watchdog?
I'm struggling with the watchdog timer (wdt) for a while. I can't get it working.
My microcontroller is a AriaG25, based on the AT91SAM925. I have used this tutorial to compile the kernel. The ...
0
votes
2answers
112 views
How do I send text to a USB device?
I'm trying to get the "Torobot" USB servo controller to work with Angstrom on a Beagle Board XM.
The servo controller registers as a USB device. The device just takes simple text commands, but there ...
1
vote
2answers
91 views
Which embedded Linux platform supports Suspend to RAM?
I am trying to save maximum energy for a certain embedded Linux application. Currently I am using Raspberry Pi. But it looks like Raspberry Pi doesn't support Suspend to RAM. What alternative embedded ...
1
vote
1answer
359 views
Beaglebone Black Device Tree for LCD4 cape
The device tree for LCD4 cape is located at /lib/firmware/BB-BONE-LCD4-01-00A1.dts When I looked into it, the declaration of those GPIO buttons confuse me. There are five buttons according to ...
1
vote
1answer
142 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?
3
votes
1answer
94 views
Is it possible to have two seperate one way (simplex) serial ports to make single tty device?
I am building embeded device, which has IR comunication with PC and it will have two IR Led/detector pairs which are one-way and are setup like this:
IR source input commands -> near embeded device ...
1
vote
1answer
140 views
Using ncurses for basic GUI on a process started inside an init script
I have a custom written application that runs on a embedded setup (buildroot). My application has to run every time the target device boots up and so I wrote an init script to do this and it works ...
2
votes
1answer
133 views
What is the meaning of the errors from my cpio command?
I have been using the following command on my system to create the .cpio archive to create an initramfs for my embedded target device
sudo find . | cpio -H newc -oc > ~/initramfs.cpio
This has ...
1
vote
0answers
147 views
Linux embedded: change time zone
I'm working on an embedded system with linux. I'm trying to change the timezone used by the operating system and I'm doing this by copying the timezone file from /usr/share/zoneinfo to /etc/localtime ...
1
vote
0answers
67 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
1answer
546 views
Copy/Mirror traffic to WAN interfaces without “iptables tee” support
I want to copy every outgoing packet to other WAN interfaces but my iptables (v1.2.7) doesn't have TEE target support. I wonder if there is another way (maybe using iproute2 or ebtables) to copy every ...
1
vote
0answers
47 views
No network interface for the lan9118 emulated on QEMU 1.4.0 overo machine
Im using QEMU 1.4.0 Ubuntu 13.04 distribution.
Im trying to make the virtrual machine part of the host network so Im ussing this command:
sudo qemu-system-arm -M overo -m 1024 -sd ./test.img -clock ...
0
votes
0answers
20 views
No network interface for the lan9118 emulated on QEMU 1.4.0 overo machine
Im using QEMU 1.4.0 Ubuntu 13.04 distribution.
Im trying to make the virtrual machine part of the host network so Im ussing this command:
sudo qemu-system-arm -M overo -m 1024 -sd ./test.img -clock ...
