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

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16
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3answers
48 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
96 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 ...
12
votes
3answers
2k views

Increasing kernel memory size

I have an embedded board with 512MB of RAM running Linux 2.6.29 and UBoot bootloader. But the kernel is able to utilize only 128MB of RAM. I tried changing the value of XCODE_MEMSIZE, which I think ...
11
votes
2answers
3k views

How do I have Linux boot with a rootfs in RAM?

The rootfs is a squashfs image and my bootloader is loading it into some address in SDRAM. What parameters do I need to pass to the kernel so It can mount the rootfs from there? Squashfs support is ...
10
votes
5answers
680 views

Which minimal but extendable Linux distribution to choose

I need an extendable Linux distribution which I can easily reduce in size so much that it fits into a 64 mb CF card. In this stripped version it will run on a Via C7 and needed is Kernel, ...
10
votes
4answers
17k 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.) ...
10
votes
4answers
3k views

Shell command to read device registers?

On a single-board computer running Linux, is there a way to read the contents of the device configuration registers that control hardware? I think it would be a wrapper for inw(), more or less. I'm ...
8
votes
1answer
2k views

Is using a read only root file system a good idea for embedded setup?

I have been tasked with running Linux as an operating system on an embedded device. The target has an x86 processor and has 8 GB CompactFlash device for storage. I have managed to use buildroot to ...
7
votes
6answers
600 views

Linux Programmable Controller

I'm looking for a programmable Linux controller for home automation and general fun projects. Requirements: Controlling electric appliances - On/Off switches and dimmers (perhaps using relays) ...
7
votes
3answers
1k views

What filesystem offers best protection for securing data against corruption due to power loss?

I am running a small uClibc and busybox based embedded system on an x86 device. I am using an initramfs but I also mounting a custom ext3 directory on a compact flash device in IDE mode that I am ...
7
votes
3answers
3k views

Safely use SD cards when power can go out at any time

We're working on a small embedded Linux system (2.6.35-ish) with a smallish internal NAND device for the OS and applications (250-500Meg) and an SD card with 8Gb SDHC SD cards for data. The unit's ...
7
votes
1answer
535 views

Attaching USB-Serial device with custom PID to ttyUSB0 on embedded

I'm attempting to get an FTDI USB-Serial device with a custom PID to automatically (or even manually) attach to ttyUSB%n, without much success. The device's normal VID/PID is 0403/6001. When ...
7
votes
1answer
3k views

Running Debian i386 binary on Debian armel via qemu

I am trying to follow this guide to set up a Ventrilo server on my SheevaPlug, running Debian armel. This page states that I can use QEMU to run the binary that was made for i386 on my arm system. ...
6
votes
3answers
68 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, ...
6
votes
2answers
788 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. ...
6
votes
3answers
482 views

Open Source router firmware options?

What distro's exist that are designed for routers? Please include the following link to the project page link to supported hardware list what distinguishes them, why pick this option friendly web ...
6
votes
1answer
382 views

Linux kernel 2.6 on ARM

I have compiled and installed the 2.6 kernel on an ARM board. I am using the ARM mini2440 board. I would like to know if there is already a way to access the General Purpose I/O port pins? Or will ...
6
votes
2answers
127 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 ...
6
votes
1answer
3k views

How can I observe memory bandwidth?

I have an embedded Linux ARM system that is showing significantly less throughput than expected on both Ethernet and USB. I suspect the memory may be contributing. Is there a way to observe the memory ...
6
votes
1answer
757 views

CLFS: Building GCC cross compiler

Currently I try to build a embedded Linux from scratch with the instructions from Cross Linux from Scratch. Everything worked fine until I tried to compile the GCC Cross-Compiler. I want to build the ...
5
votes
3answers
488 views

Is making /etc directory read only a bad idea?

I have an embedded system setup built using buildroot and using initramfs. It runs on compact flash device where I have created separate ext3 partitions to mount /etc/ and /var directories as well as ...
5
votes
2answers
608 views

Resources for very low-level (board bring-up)

I've worked with a few embedded systems, but now I'd like to make my own piece of hardware and despite a pretty thorough knowledge of Linux, I have no idea how to get Linux up and running on new ...
5
votes
1answer
2k views

What is a “watchdog reset”?

After reading this question, I was a little confused; it sounds like some daemon reacting by rebooting a system. Is that right? Is it a common occurrence in embedded *nixes?
5
votes
1answer
323 views

What distribution-maintained cross-compile toolchain packages exist?

I have just learned of Gentoo's sys-devel/crossdev package. This is a package that is useful for creating a cross-compiling toolchain. Are there any other such packages out there on other ...
5
votes
1answer
881 views

Defragging RAM / OOM failure

This question is fairly lengthy, so I'll ask the questions at the top and then go through my method of coming to the questions: Did (Busybox based) rm not execute because there wasn't enough ...
5
votes
2answers
9k views

Why does sh say “not found” when it's definitely there? [duplicate]

Possible Duplicate: “No such file or directory” lies on Optware installed binaries I'm trying to add ebtables to a little router box. I went and got a binary compiled for the ...
5
votes
1answer
723 views

Debugging a Segmentation Fault

I have an application that runs on an embedded Linux device that I am expanding with new features. The new features require GLib so, I am dynamically linking the required libraries to the application. ...
5
votes
1answer
353 views

Embedded linux LCD not calibrated

I have attached a new LCD to my embedded Linux device and when I run the system I found that it is shifted to the right. (the display starts from the middle of the LCD) I found 2 frame buffer drivers ...
4
votes
4answers
2k views

How do I install GCC on a system with no compiler?

I've been messing around with my NAS which runs on Linux. I have root access, but there is no compiler. I seem to remember something about being able to compile on another system, but I'm not certain. ...
4
votes
1answer
99 views

What does this dd command do exactly?

I have the 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 * ...
4
votes
1answer
822 views

Tunnel through a NAT

I have a router that provides internet connection to a single client device via a wireless cellular data network. This network provides non-public IP addresses which gets natted. I would like to get a ...
4
votes
1answer
428 views

Embedded board with apache

I'm working on a Davinci DSP ARM embedded board. The board itself is the Texas Instruments 816X/389X EVM. I'm currently trying to get apache working on the board. The problem is that the SDK for the ...
4
votes
1answer
494 views

Capturing OS/hardware communication / reverse engineering drivers

This may be too broad of a question, but I'm not really sure what exactly I'm looking for. My main question is how the open source community reverse engineers windows drivers (for say, video cards) to ...
4
votes
1answer
227 views

Making a recovery partition in embedded Linux

I have an Atmel SAM9X system running Angstrom. I am trying to make a recovery partition so when a user holds a button during boot up the recovery partition boots up. I have modified the bootstrap so ...
4
votes
1answer
457 views

Can I use a chroot on my dev machine to build an application to run on embedded linux installation?

I am trying to develop an application to run on an embedded linux installation. It comes with an older version of libc than I have on my development maching. If I were to create a chroot environment ...
4
votes
3answers
6k views

Kernel panic - not syncing: No init found. While booting from U-Boot

Kernel mounted the root file system but can not find any init script. I'm sure that script exists in my ramdisk.img! I also checked out this and GE863-PRO3 U-BOOT Software User Guide 1VV0300777 Rev. ...
4
votes
1answer
366 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 ...
4
votes
1answer
225 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 ...
3
votes
2answers
296 views

Databases for embedded Linux?

I need to choose a database for an application on an embedded linux platform. Any suggestions on which databases are typically used with embedded linux? Please let me know. Regards Radha.
3
votes
2answers
281 views

Ethernet Sniffing Embeded Device

I recently dug out some prototyping equipment from the trash and I want out figure out what the heck it is. It has a port labelled 'Ethernet' and when I plug it into a router the lights flash like its ...
3
votes
1answer
545 views

How to test the touch screen on embedded devices like iPhone / iPad / Kindle? [closed]

I want to test the touch panels on embedded devices like iPhone, iPad and Kindle against following criteria: Do a gesture, like tap, swipe, pinch ( zoom in/out) 10000 times and validate that every ...
3
votes
3answers
666 views

Debugging ethernet before NFS boot

I'm trying to boot Linux from U-boot on an embedded ARM board using a filesystem on a remote machine served via NFS. It appears that the ethernet connection is not coming up correctly, which results ...
3
votes
1answer
159 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 ...
3
votes
1answer
71 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 ...
3
votes
2answers
584 views

Inittab seems to ignore remount,rw /

I have an embedded system that boots off compact flash and runs with the initrd.img ramdisk mounted as root. When booting, it mounts the initrd image ok in read only mode but then when inittab runs, ...
3
votes
1answer
748 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 ...
3
votes
2answers
247 views

Linux security vulnerabilities?

A while back I started an embedded project using the 3.2.10 kernel. Now the project should go into production and the stable kernel is 3.2.16. I would prefer not to upgrade anything to avoid ...
3
votes
1answer
77 views

Booting using initramfs instead of uramdisk

I am working on Zynq Microzed board. It is booting perfectly with uramdisk.image.gz but I trying to boot it with initramfs.cpio. In this regard I have made following changes in header files of ...
3
votes
2answers
197 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 ...
3
votes
1answer
47 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?