date int64 1,220B 1,719B | question_description stringlengths 28 29.9k | accepted_answer stringlengths 12 26.4k | question_title stringlengths 14 159 |
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1,485,283,266,000 |
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 is no TTY associated with it. So I'm not sure how to send commands to it.
Can I just send data like this (assuming tha... |
Finally Success:
I found that the Torobot USB board could be communicated with an Arduino serial driver. Conveniently this is available through opkg:
opkg install kernel-module-cdc-acm
When the board is plugged in, it comes up as
/dev/ttyACM0
From here you can simply echo commands to the device.
echo "#8P1500T1... | How do I send text to a USB device? |
1,485,283,266,000 |
I am having heavy problems similar to what discussed in this question.
In my case though, I have a very recent kernel (5.3) for a small embedded processor (mips, mt7628) and boot process stops for over 6 minutes till I get the kprint:
[ 402.804482] random: crng init done
after that boot sequence continues normally:
... |
I have been directed to use haveged and it actually dramatically shortens startup time:
[ 12.477886] random: crng init done
I will leave this answer for whoever will stumble into the problem.
I will wait for better answers before accepting this.
Note: this source hints there could be some kind of kernel bug respons... | Linux embedded: boot stopped by "crng init" for LOOOOONG time |
1,485,283,266,000 |
I am required to write some software to run on Linux installed on an x86 based embedded setup that has a 8GB compact flash drive for data storage. The critical requirements are logging measurement data to file every 30 seconds, and robustness to power loss (my system MUST be able to reboot successfully every time and ... |
Run your system off RAM (faster, read only, will come up in known good state, etc.)
Log your data to a separate partition on the USB stick. Might try mounting it with sync if your writes are not too frequent.
| Using ramfs on embedded system |
1,485,283,266,000 |
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 power cycle,
Nothing works during this hang, it looks like system is frozen, It doesn't even respond to sysrq keys
I ass... |
Well, We did code reading as it was being suggested in the comments and found the section of the patch where system may go into infinite loop(in irq) and won't come out of it.
However when we put printk in that irq function issue was not getting reproduced. (timing issue you know!)
So finally my colleague tried old ... | How to debug Linux hang? |
1,435,702,788,000 |
I'm working in an embedded Linux system trying to get it booting its root file system in ram using initramfs. The system comes up for the most part but then has trouble in the init scripts. I've narrowed the problem down to the following.
The system cannot recognize any relative paths. Let me explain more...
Not only ... |
After reading this post, the problem is solved!
I had noticed when running the mount command that two entries appeared for /:
rootfs on / type rootfs (rw,relatime)
devtmpfs on /dev type devtmpfs (rw,relatime,size=209064k,nr_inodes=52266,mode=755)
proc on /proc type proc (rw,relatime)
devpts on /dev/pts type devpts (rw... | Relative path to anything not working (while running from initramfs) |
1,435,702,788,000 |
I have spent some time getting my BeagleBoard XM computer up and running with the default Angstrom demo image after it has sat unopened for close to a year. I've been able to interact with it through the serial port, and then through putty. I can install packages such as Apache, and it seems to work fine.
However, wit... |
The answer was that the demo version is mounted to a ram disk.
So YES - you must build the image. The way I went about it was to build a Linux system on an older laptop (which of course opens its own can of worms) and build the image from there.
Once you have a working version of Angstrom that is NOT loading onto r... | How do I install packages permanently on my Beagleboard? |
1,435,702,788,000 |
I have an embedded system based on the Intel-Atom with PCH which we are busy developing. In the embedded environment I have:
A Serial console through the PCH which means this doesn't work with the standard kernel. (as CONFIG_SERIAL_PCH_UART_CONSOLE is required)
The SATA drive is only available in the embedded environ... |
I managed to solve my problem with debootstrap, here is a quick run-down of the process I followed.
unmount usb
Partition the USB (4GB)
Zap out GPT with gdisk, as my board didn't want to boot GPT.
Created just one linux partition, nothing else.
I had lots of problems getting a usb drive bootable on my embedded system... | Installing Debian on Embedded system with serial console or network console (PCH) |
1,435,702,788,000 |
I've heard that Android is based on linux (or unix?). That means, engineers at google modified linux code to run on android phones or tablets. I would like to become those engineers someday. Where should I start? Should I start looking at embedded linux?
|
Actually google did more writing an app platform / virtual machine system to run on top of linux than they did modifying linux. They basically just used it as a base to build off of, they hardly had to touch it.
As for your question, just start doing things. Get yourself some linux distros, install them on your comput... | How to start customizing linux? |
1,435,702,788,000 |
I notice that ncurses's terminfo database on /usr/share/terminfo is about 7MB (I compiled it myself). This is too large if I want to deploy it on an embedded Linux of 64MB disk space.
Is there a way to reduce its size by deleting unneeded entries and keep the most-used ones? And what's is this actually for?
EDIT: Is t... |
With ansi, cygwin, linux, vt100, vt220, and xterm terminfo definitions, I expect you'd be able to hit 98% of the terminal emulations that you'll encounter in the wild.
Even terminal emulators that have a different native mode can likely be directed to emulate vt100/vt220 modes, often without user intervention.
| How to reduce ncurses terminfo size |
1,435,702,788,000 |
I am working with an embedded Linux (ARM/busybox) system. It has systemd and the timedatectl system executable, but it does not have /etc/timezone, /usr/share/zoneinfo, nor the zic timezone data compiler program.
I have plenty of system diskspace on this embedded system.
Is it possible to copy the /usr/share/zoneinfo ... |
Yes, the binary timezone files are platform-agnostic.
This is noted e.g. in the Wikipedia article "tz database":
The tz database is published as a set of text files which list the rules and zone transitions in a human-readable format. For use, these text files are compiled into a set of platform-independent binary fi... | Is Linux /usr/share/zoneinfo/ Platform Agnostic? |
1,435,702,788,000 |
Running on a custom rockchip board with Ubuntu 14.04. I look at interfaces with ifconfig:
...
wlan3 Link encap:Ethernet HWaddr 08:ea:40:d7:63:27
inet addr:192.168.12.1 Bcast:192.168.12.255 Mask:255.255.255.0
inet6 addr: fe80::aea:40ff:fed7:6327/64 Scope:Link
UP BROADCAST RUNNING... |
The nl80211 standard doesn't support the rtl8188eu driver , use wext the old driver.
To connect use the following command as root (you don't need to configure anything);
wpa_supplicant -B -Dwext -c <(wpa_passphrase "ESSID" PASSWORD) -i wlan3
dhclient wlan3
If you have already a wpa_supplicant.conf configuration fil... | `iw dev $interface scan` not working on embedded device |
1,435,702,788,000 |
Is UBoot able to boot via fatload/ext4load from an EMMC's General Purpose Partition or Boot Partition? I am able to show files from the User area, just not partitions created as hardware partitions. These partitions can be created by using UBoot's "mmc hwpartition" command. It seems odd UBoot can create these partitio... |
Yes, you can access the GP partitions from uboot.
As described here http://u-boot.10912.n7.nabble.com/How-to-access-GP-partitions-from-uboot-2015-04-td212394.html you can use the "mmc partconf" command's last argument to tell the eMMC to bring out different parts (e.g. the GP instead of the user area). After you run t... | How to load files from an EMMC's General Purpose Partition or Boot Partition, using Uboot |
1,435,702,788,000 |
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 symlinks already existed beforehand, created at installing the firmware.
$ rm uw_cert.cer
I tried to remove uw_cert.cer... |
the filesystem you are trying to remove symlink from is probably an initramfs which is loaded on ram at boot, so the one you are modifying is the ram copy of the initial ram disk, which is discarded at shutdown.
If you want to modify the ramdisk file, you need additional information. Which bootloader are you using? Fr... | Canot remove symlinks: after reboot, symlinks re-appear |
1,435,702,788,000 |
After installing ssh server on my remote machine (which runs embedded Linux), I tried to connect to ssh server from host machine but it failed.
This is because I could not specify user account when connecting to ssh-server (ssh connection requires to enter password of an account) since my target embedded Linux does n... |
Dropbear calls the getpwnam standard library function to get information about user accounts. On systems with GNU libc (the standard library for non-embedded Linux systems), this function can query several types of databases through the NSS mechanism, including /etc/passwd. Embedded systems may run a variety of libc (... | How to connect to ssh-server running on embedded linux without /etc/passwd? |
1,435,702,788,000 |
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 multiple or 4 or out of RAM scope? If my system has a bus 32-bits wide, given an address how can i know if its aligned ... |
In short an unaligned address is one of a simple type (e.g., integer or floating point variable) that is bigger than (usually) a byte and not evenly divisible by the size of the data type one tries to read.
Address % Size != 0
Say you have this memory range and read 4 bytes:
+---------- 8 %... | Know when a memory address is aligned or unaligned |
1,435,702,788,000 |
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 kernel settings related to the wdt looks like this:
CONFIG_WATCHDOG=y
CONFIG_AT91SAM9X_WATCHDOG=y
The kernel has b... |
I've changed my kernel configuration to this:
CONFIG_WATCHDOG=y
CONFIG_SOFT_WATCHDOG=m
CONFIG_AT91SAM9X_WATCHDOG=y
Now my watchdog timer was running. I only had to edit /etc/watchdog.conf in order to set up tests.
| How enable watchdog? |
1,435,702,788,000 |
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, booted the board via UART and loaded u-boot via xmodem. As a result I can enter u-boot commands.
From my understandin... |
The README file for the board, which is found at board/ti/am335x/README in the source tree has a section on writing to the eMMC. It talks about Falcon Mode, which is having U-Boot run Linux, but covers flashing U-Boot itself as part of that.
| Flashing U-boot on beaglebone black |
1,435,702,788,000 |
I'm trying to use a compressed squashfs ubi volume as my root file system. The idea is to have two ubi volumes. Volume one contains a read-only squashfs file system. Volume two is re-sizable and uses the remaining flash space. It contains a writable ubifs file system. These two ubi volumes are to be overlayed using ov... |
Squashfs needs a block device to run, thus you need the block emulation over UBI. First make sure it is enabled in your kernel.
You can test this by using the ubiblock command on a running system. For example, running ubiblock -c /dev/ubi0_0 will create the devnode /dev/ubiblock0_0.
Once you have the dependency, you ... | Using squashfs on top of ubi as root file system |
1,435,702,788,000 |
I'm running linux on the beaglebone black. My system is running directly from the sdcard. To change the IO scheduler I need to configure /sys/block/xxx/queue/scheduler where xxx is the mounted drive. However there are only entries for mmc and ram in the /sys/block folder.
How do I change the IO scheduler for my sys... |
You have 2 ways to setup the IO scheduler on Linux.
You defined a default IO scheduler for all block devices. You can do this by adding the parameter elevator=<scheduler> (e.g. elevator=deadline) to your boot prompt (if you use a recent Grub version, like v1.99 or 2.0, you can add this in the file /etc/default/grub, l... | Selecting IO scheduler on external drives |
1,435,702,788,000 |
I have enabled CONFIG_CMD_TFTPPUT in U-Boot, but I am not able to use it.
I have set the serverip and ipaddr environment variables. When I use it as follows, it times out:
u-boot# tftpput
link up on port 0, speed 100, full duplex
Using cpsw device
TFTP to server 192.168.1.3; our IP address is 192.168.1.106... |
As "wmill' rightly commented in his answer that most tftp servers will write to file only if it exists.
In my case also it was the same problem. tftpput from u-boot works fine. I installed tftpd-hpa and configured it as follows to create a file.
edit /etc/default/tftpd-hpa as follows,
# /etc/default/tftpd-hpa
TFTP_US... | tftpput in U-Boot: error: 'Access violation' (2) |
1,435,702,788,000 |
Suppose a process, among other things, is posting https requests, for example with curl.
Assuming I have root privileges, is there a way to intercept such requests and respond with an http error or, even better with acknowledgment?
I am using an embedded device, so I have limited access to software libraries.
|
What you are asking for is called a proxy http server.
The software receives http requests and passes them on or rejects them (logging too) It needn't sit on your embeded device, however your device would need to be configured to access the proxy instead of going directly to the internet.
apache nginx are two examples... | catch http requests from another process |
1,435,702,788,000 |
I have two PC Engines Alix 2d2 which I've been given and I'm trying to install an (BSD or Linux based) OS on. Currently one has a version of openWRT (the other had openWRT until I formatted the CF card and put on a version of FreeDOS (I don't know if this works because no console)). Both boards were in working order b... |
You need a null modem cable (or a null modem adapter attached to your serial cable) if both ends of the connection are implementing the DTE side of the RS-232 protocol.
Typically computers are DTE and peripherals like modems are DCE. Your embedded board is halfway is kind of a hybrid (runs OSes that also run on PCs, b... | Using serial console and trying to log into embedded system |
1,435,702,788,000 |
I got an embedded device with RPM on (no Yum). The way I install packages now is by downloading the proper .rpm file from rpmfind.net and running rpm -i package.rpm. This process repeats for every missing library until the program finally runs.
There must be a better way to do it.
Can I automatically solve the depende... |
You may want to try new project MicroDNF https://github.com/rpm-software-management/microdnf This is just small binary and will resolve the dependecies and install them.
| Installing rpm packages and resolving dependencies on an embedded device |
1,435,702,788,000 |
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 password, or how to set account and password? I need to get account and password on embedded linux to run ssh server, which ... |
If there is no /etc/passwd, then your embedded system is not running what is usually known as the Linux system, but rather a different operating system which is also based on the Linux kernel. A famous example of an operating system which uses on the Linux kernel but is not Linux is Android. Android doesn't have user ... | How to check my account on embedded linux without "/etc/passwd"? |
1,435,702,788,000 |
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 I see the count for errors seems to be pretty high (353 errors). Is there any easy way of determining what those errors... |
I believe you can use Wireshark to determine why these packets are being retransmitted. Excerpted from this thread in the Wireshark forum, titled: Wireshark-users: Re: [Wireshark-users] tcp errors detection.
excerpt #1
On Sun, Apr 18, 2010 at 4:17 PM, Victor lyamtsev wrote:
Hi,
how can i locate retransmission error ... | High RX packet error count with modem - how to analyze? |
1,392,205,979,000 |
I recently attended an embedded Linux course that stated that uClibc does not support the use of pthreads and that it only supports linuxthreads. Furthermore, the course instructor implied that linuxthreads were next to useless. However, when reading a number of online articles, the implication is that they are in fac... |
Starting with version 0.9.32 (released 8 june 2011), uClibc is supporting NPTL for the following architectures: arm, i386, mips, powerpc, sh, sh64, x86_64.
Actually, both are an implementation of pthreads and will provide libpthread.so.
| Does uClibc support using pthreads? |
1,392,205,979,000 |
I have a D-Link DI-624 rev. D2 Router. It is based around an Atheros AR2316A-001 chipset, and has 8MB RAM.
I opened the device to check for actual parts use in it, and I can confirm, it is indeed the AR2316A-001 chipset with PSC A2V64S40CTP (8MB RAM). I couldn't locate the flash chip, the original firmware is 1MB in s... |
Until you determine, what type and size of Flash ROM is used in the device, you should not risk flashing it with anything other than dedicated firmware. Atheros chipsets are very common across a wide range of wireless devices and the sole fact of using a particular chip does not guarantee that the entire device will w... | D-Link DI-624 H/W ver. D: Flashing OpenWrt |
1,392,205,979,000 |
I am developing an embedded Linux system. The system is usually installed by creating a ISO file which is written to a USB stick the board can boot from.
To make the installation possible to do automatically (say, over night) I would like to be able to do the installation on the board while the old system is running.
... |
I can think of different ways to do what you want. All of which carry a level of risk and difficulty. The main risk being that if the install goes wrong/breaks you will end up with an unbootable system that needs installing manually.
My main thought (which depends on your boot loader and similar) would be to use exact... | Swap root at runtime |
1,392,205,979,000 |
I am currently working on an embedded board with a WM8776 which uses the MCASP1 of the AM335x. This works as expected and has expected behaviour.
What I now want to do is make a driver which can switch frequencies. I have two clocks which go in into the MCASP via a clock mux via a GPIO. If this GPIO is high I have an ... |
Ok two things: between the application playing back a stream of PCM samples and the kernel side of ALSA, there's the userland alsalib with its optional internal resampling. If the application did not disable that but requested a device as is, the kernel had no way of knowing what the original sapling rate was. It's si... | Change clock bitrate (ALSA, PCM) at runtime AM335x |
1,392,205,979,000 |
I have a custom embedded linux board with a lan7500i-ABZJ connected over USB.
So I compiled the linux kernel (using buildroot) with the smsc75xx module built in. The startup kernel messages indeed show:
[ 5.315124] usb 1-1: New USB device found, idVendor=0424, idProduct=7500, bcdDevice= 2.00
[ 5.324072] ... |
ifconfig (or here probably busybox ifconfig) displays RUNNING in addition to UP for a NIC which is both administratively UP and has detected a carrier (ie: a remote NIC, switch etc.). The lack of RUNNING means the NIC is not connected or couldn't be set in such a way as to properly detect the NIC on the other side of ... | USB to ethernet: fail to transmit any packages |
1,392,205,979,000 |
From my understanding, in systems without bus support for discovery/enumeration (mostly embedded systems), the dtb files are used to describe the hardware and allow the kernel to use it once it has been loaded into to memory.
So, assuming we just want to update the kernel for such a system, do we need to also update t... |
Mainly, kernel and device tree are supposed to be independent from each other, so yes: Usually you can use a freshly compiled kernel along with the old dtb and vice versa.
Of course, this stops being true if the device tree relies on certain versions of device drivers or the new kernel expects different device tree a... | with a static hardware, do I need to recompile the dtb every time I update the kernel? |
1,392,205,979,000 |
I plan to run an Electron app on my UDOO Neo i.MX6 board with the official st1232 7'' touchscreen kit for UDOO Neo. I created a custom Linux distro with Poky (thud branch) to be able to build a "ready to boot" image. I enabled the "x11-base" image feature to have all the Xorg packages and I have the meta-freescale lay... |
I simply added this patch to my layer and now it works.
| How to configure X11 for embedded i.MX6 board with touchscreen? |
1,392,205,979,000 |
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 device use serial communication and command line, this also requireds to a http server on LAN. The part of commands
ro... |
Yes - this method is suitable for embedded devices with tight resources and/or no writable filesystems (readonly or no free space). Grabbing additional binaries (not just busybox) into RAM is pretty much the only way to go if no write permissions anywhere (and you don't want to risk bricking by flashing the firmware i... | Replacing busybox in an embedded device |
1,392,205,979,000 |
I have an embedded device which runs linux(arm). I am trying to update the executable through ethernet using scp command. But I got to know that sshd is not running in the device . I need to install the ssh library in device. But I have only access to a serial port (debug) and ethernet.I have compiled ssh library usin... |
Just copy the sshd to the embedded device with tftp. For e.g. at /usr/bin/sshd and execute it. Then try connecting to the embedded device.
| SSH demon not installed in linux embedded device |
1,392,205,979,000 |
I'm making a special "installer" for an embedded system where I'd like the kernel to boot up, execute a set of things very late in the process where the peripherals have been set up and then reboot the system without the login prompt ever happening.
I'm vaguely familiar with init and runlevels, I presume at this point... |
For Debian 7 and earlier, the easiest option is to put your code in /etc/rc.local. This runs at the very end of the boot sequence, just before the login screen is displayed when you boot into console mode, or just before X is started otherwise. Until this script exits, nothing else happens, so if you reboot the system... | Late running of scripts during bootup, ending with a reboot without the login prompt |
1,392,205,979,000 |
Im using a private IP address and I want to keep alive SNAT entries in my Router (Gateway) for at least two hours (some windows apps of my network are using TCP keepalive set to 2 hours). Gateway is a Linux machine so i set nf_conntrack_tcp_timeout_established and nf_conntrack_generic_timeout values to 7400 seconds:
e... |
The root cause was that the conntrack code in the kernel has been modified. As we are using a embedded linux distribution modified by our provider, the function that refresh the timeout for the SNAT entry was pointing to a special function used for provide one of the our provider new 'features'. I have fixed it and no... | Conntrack TCP Timeout for state stablished not working |
1,392,205,979,000 |
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 Key (a 10-digit hex code using lowercase) in /etc/network/interfaces
When I do a ifup wlan0, it goes through the process o... |
Thanks to @slm for sending me to the how-to reference.
It appears the biggest issue was that NetworkManager was running and because I have no GUI (the BeagleBoard version of nmcli does not have the "connect" feature allowing for the creating of new interfaces on the command-line, and I am only connecting to the beag... | Why is my wlan0 interface on Angstrom (Beagleboard) "Not Associated"? |
1,392,205,979,000 |
I have an alix board on which I have installed debian4alix (sqeeze). After using it for a while I noticed that the write performance of the board was pretty low.
I ran the following test:
dd count=100 bs=1M if=/dev/urandom of=/var/www/cgrid/test
This yielded the following:
100+0 records in
100+0 records out
10485760... |
I am quite certain the board is slower then desktop in terms hardware. But urandom make it worse.
The board is using a 500MHz CPU vs 2-3GHz desktop CPU. With if=/dev/urandom, your test is more about how fast the system can handle urandom. You are comparing CPU performance, not I/O.
Additionally, if the board only have... | Alix Board write performance |
1,392,205,979,000 |
I build my own linux distribution using Yocto for Rpi CM4. I would like to have a possibility to update it remotely, without using Balena Etcher, just upload the built image and call some commands via SSH.
How can I do that? I found swupdate yocto layer but I cannot confirm that it will work with CM4
Thanks!
|
So I used RAUC. It has support for RPI CM4/4B.
Just add those layers to yocto:
https://github.com/rauc/meta-rauc
https://github.com/rauc/meta-rauc-community/tree/master/meta-rauc-raspberrypi
Then follow the instruction from readme.md from the second URL.
Works without any struggle.
| Embedded linux remote update |
1,392,205,979,000 |
I'm unable to successfully set the bDeviceClass, bDeviceProtocol, or bDeviceSubClass when configuring a device as an RNDIS gadget in /sys/kernel/config/usb_gadget/g1.
I'm configuring the gadget with the following values and can read them back successfully in Linux:
echo 0xef > bDeviceClass
echo 0x02 > bDeviceSubClass
... |
The solution was to modprobe the libcomposite module instead of g_ether directly.
That allowed the USB device descriptors to bet set as expected.
This also requires the script to bind the gadget to UDC before exiting.
I've included an admittedly maximal example, but it's what I'm using and it's what works for me.
VEND... | Unable to set USB gadget device class and protocol |
1,490,658,563,000 |
How to use dd command to download mtd block from embedded Linux-based device?
# cat /proc/mtd
dev: size erasesize name
...
mtd3: 003a0000 00010000 "DRTI2"
I need download mtd3 block, so
dd if=/dev/mtdblock3 bs=BYTES count=BLOCKS | nc 192.168.1.30 5555
What should be correct bs and count values and how to calcu... |
dd and cat are equal if you want to read full mtdblock3. With dd it will be: dd if=/dev/mtdblock3 | nc 192.168.1.30 5555. Just omit optional bs= and count=.
| Using dd command to download mtd block |
1,490,658,563,000 |
I am following CLFS book (GIT-20140613-arm version), and I have a issue when building GCC with armv7 and neon combination. Target info here.
My host is a clean Debian 8 with gawk, build-essential, texinfo and libncurses5-dev packages. More details can be found here.
I made this patch to build binutils with gcc-4.9.
Fo... |
For BeagleBone Black, the correct environment settings is armv7-a, as we can see here and here, and we need to pick up the kernel settings from here with bb.org_defconfig, and use headers from here, and patches for gcc from here, and remember to build final gcc with --disable-libsanitizer.
I used the following command... | CLFS for ARMv7 neon |
1,490,658,563,000 |
Many routers run a Linux OS and abrupt power failure can happen. Considering this - how do they handle the possibility of file system corruption caused by a power failure? If they make the system read only, how are you able to change settings?
|
Routers and other small linux devices do not use hard drives.
They use different types of RAM:
DDR RAM as working storage
ROM for system image (Kernel + OS)
Non Volatile RAM for Settings (/dev/nvram)
In case of an crash they boot again and reinitialize the OS, so nothing get's lost.
| Embedded Linux Power Failure Issues |
1,490,658,563,000 |
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 over GRE. RouterA is connected to internet via ppp0 as RouterB. Both internet connections are PPPOE (PPPoEoA PVCs).
So... |
The problem was related with the question I asked on ServerFault, IP/GRE compiled in kernel but gre0 interface doesn't exist.
I solved the first question by letting GRE demultiplexer driver in gre.c to register the GRE protocol handler in kernel. But I have found that when a GRE packet arrives GRE handler is not poin... | Transparent Ethernet over GRE not forwarding traffic |
1,490,658,563,000 |
Hi I recently run an application or an app and now I want to know the cpu status info so i need the PID of the application i have run recently. But i have so many PIDs in the /proc directory so how can i know the PID of the particular application for example "my-example" application binary i recently executed.
|
There are some command line tools for process management you can check:
You can use pidof <name>, e.g. pidof bash, to get the PID of a process given the program name
You can use ps -aux to get a listing of currently running programs with their starting time and PID. You may look for your program in the listing.
You c... | How to find pid of an application recently run on linux? |
1,490,658,563,000 |
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.
|
The information that df produces comes from the statvfs() system call. If your embedded system does not have the df command installed, perhaps it has one of the common scripting languages, using which you can write a one-liner to access the same system call?
python -c 'import os; print os.statvfs("/")'
If it doesn't ... | How to know free disk size witout df command? [closed] |
1,490,658,563,000 |
I have to prepare a computer to give away, and I do not know who is going to use it. The computer has Debian installed, and the HDD is entirely encrypted. All users have their storage on the server. I have been believing that if it meet some conditions below this will safe huge works for all computer departments:
Any... |
It's not really possible. You simply can not prevent someone powering on/off a computer, or indeed them doing whatever they want with it once they have hands on access.
I've done something similar, for a server. It uses full disk encryption and produces its key based on hardware data such as CPU type, Mac Address, amo... | Secure the content of a hard disk |
1,490,658,563,000 |
I wish to install Xenomai which works on Linux providing a kind of hard real time environment.
x86/64 architectures are supposed to contain the "System Management Mode" which prevents them from being used for hard real time systems.
By "System Management Mode" I mean this: http://en.wikipedia.org/wiki/System_Managemen... |
System Management Mode is not the only thing that makes x86 bad at hard real time. The unpredictability of the execution speed due to caches, pipelines and so on makes x86, and any other high-end processor, bad at real time. All these features that make a processor fast on average also make the worst case difficult to... | System Management Mode in embedded systems |
1,490,658,563,000 |
For a linux kernel with virtual memory and disk storage, pages are swapped back and forth into swap area. But embedded systems generally use NAND flash instead of disk. A NAND flash has a limited number of writes allowed, as guaranteed by its manufacturer (although the limit is high in most cases).
How the wear out in... |
Embedded systems running on flash don't use swap. Please don't confuse that with virtual memory though - virtual memory has many more usages then just swapping to disk.
| NAND flash memory wear & virtual memory page swap |
1,490,658,563,000 |
In a small embedded Linux Busybox based system, by default inetd is being started at boot but inetd.conf has every service commented out as none of them are being used.
Does this mean we can just remove the call to start inetd or could it be required by some system process down the line?
|
There's no need to run inetd unless it's being used.
If you were really cautious you could look for uncommented non-blank lines in /etc/inetd.conf and only start the daemon if one or more was found. This implies that you would be changing your system configuration at some point in the future. If you're not doing that ... | Can we kill inetd if there's nothing using it / no config? |
1,490,658,563,000 |
Here I read:
$ cd /media/mmcblk1p2
$ tar xf /media/sda1/mfg_images/st-image-bootfs-openstlinux-weston-stm32mp1-som.tar.xz
but as source file I don't have a compressed file, instead I have an ext4 image for that partition. Should I use dd with of=/dev/mmcblk1p2 or I need to use another approach?
|
You can mount the filesystem image directly into your filesystem:
mkdir -p /mnt/img
mount -o ro,noload imagefile.img /mnt/img
and then you can retrieve the file directly from the appropriate place underneath /mnt/img. (The ro,noload options mount the filesystem read-only. Omit them both if you want read/write access.... | Extract file from ext4 image and copy file to device |
1,490,658,563,000 |
Recently Debian Wheezy LTS released a new version of a package, e.g. wget 1.13.4-3+deb7u4 (see announcement here), on my system I still have an old version e.g. wget 1.13.4-3+deb7u3 installed.
My sources.list only have one line:
deb http://security.debian.org/ wheezy/updates main
My preferences file is not exiting at... |
I found the solution:
in the command apt-get update there was another sources.list file used with -o Dir::Etc::SourceList=/etc/apt/security-sources.list
But apt-get upgrade was called without this other source.list file - I assumed it is not needed anymore - but it is.
Once I've used the same sources.list file for upd... | apt-get upgrade doesn't find newest packages |
1,490,658,563,000 |
what is proper command compress mtdblock with 'tar' before sending it via TFTP?
tftp -l /dev/mtdblock3 -p 192.168.100.40
|
tar is not a compression tool, just use gzip to compress a single file.
You can pipe gzip -c to tftp -l /dev/stdin on the busybox shell. For example:
gzip -c /dev/mtdblock3 | tftp -l /dev/stdin -r mtdblock3.gz -p 192.168.100.40
If there's no /dev/stdin, try with /proc/self/fd/0 instead.
| Compress mtdblock with 'tar' before sending it via TFTP |
1,490,658,563,000 |
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. u-Boot correctly finds them and creates a bad block table with the offsets given by the nand bad command:
Device 0 bad ... |
We've figured out that the problem is with squashfs itself. It has no support for bad block detection, as stated here:
http://elinux.org/Support_read-only_block_filesystems_on_MTD_flash
So the possible solution is to use another filesystem or use UBI to manage the bad blocks and then keep using squashfs.
| Kernel does not skip bad blocks when mounting filesystem |
1,490,658,563,000 |
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 fine. However, part of the application has a very basic 'GUI' written with ncurses. The problem I have is that it works fi... |
I'm no quite sure I've understood your problem. I assume that your application starts some kind of curses GUI and you want to log in remotely and the - somehow - connect to that GUI (but the application is already running).
I suggest to use screen (http://www.gnu.org/software/screen/) to start the application on a de... | Using ncurses for basic GUI on a process started inside an init script |
1,490,658,563,000 |
I could find the ip address of my board by using ifconfig but I need the port number as well to set Linux TCF agent. I tried netstat with several options but could not find as it returns too many and cannot scroll the screen to the top. So is there a way to find the port number given the ip address?
|
Prefer using ss
netstat is deprecated (no update since 2011), as said in the man page, in the NOTE section.
So you probably should use ss, which is part of the iproute2 package.
You can use the following command:
ss -nltp
-n will prevent names resolution
-l displays listening sockets
-t is used for TCP transport (if... | How to find the port number given the ip address |
1,490,658,563,000 |
I need to calculate how long linux takes to shutdown. I am running an embedded busybox linux on ARM i.MX7. I looked in /var/volatile/log/messages but that only shows the last startup. I need to know how long the system takes to shutdown after eg shutdown -h -P now.
How can I get a reasonably precise measurement?
|
There is an obvious problem: Shutting down the system requires at some point to close filesystems, so log files can never catch the last bit.
Typically, you have some serial console on such a system and if you enable kernel logging to the console, you have all output with time stamp until immediately before the kernel... | How to measure how long linux takes to shutdown |
1,611,532,540,000 |
I would like to specify mount options for my rootfs as per instructed here however I am unsure where this should be done. I've looked through the genimage docs and there was no generic option to pass a mount option to a generic partition.
I found a similar thread here but the answer was somewhat inconclusive.
|
For context I'm working on a Raspberry Pi 0.
Using @A.B 's comment, I added rootflags=fastboot to cmdline.txt which is passed to the kernel on boot. This solved my issue.
| Specify rootfs mount options |
1,611,532,540,000 |
I have been trying to locate ARMv8 32bit package repository since yesterday to download packages that I would make use to carry out some analysis with radare. I had found repositories from archlinux and centos but unfortunately all these packages are aarch64 (ARMv8-64bit) which radare is having issues with analyzing. ... |
Technically ARMv8 consists of both a 64-bit architecture called Aarch64 and a 32-bit architecture called Aarch32. Some ARMv8 chips only have the 32-bit architecture. But in practice “ARMv8” is usually used to mean Aarch64. Aarch32 is backward compatible with ARMv7 and adds very few extensions to it. So I guess there i... | Unable to locate DEBIAN ARMv8 32-bit packages from Internet |
1,611,532,540,000 |
I'm trying to set up a u-boot on an imx8 board to load environment variables from a uEnv.txt file on the first partition. I've got it working so that it loads the file, and now I'm trying to import that data with env import. However, the u-boot version built with the BSP from the vendor doesn't seem to have env impo... |
You need to enable CONFIG_CMD_IMPORTENV.
| How can I add missing "env import" to u-boot? |
1,611,532,540,000 |
Board with ARM926EJ CPU, running embedded Linux v2.6.26.5, on NAND Flash device, NAND 32MiB. Linux is on MTD partitions on NAND device.
How can I backup Linux kernel image (SP2Xcybertan_rom_bin) from serial interface? Since there is no TFTP option to transfer file from board to host PC via tftp.
Can I read nand to som... |
The steps to do this would be as follows:
First assuming the update uImage is correct
update.kernel=echo Update kernel && tftpboot 0x20000000 uImage && nand erase 0x80000 0x180000 && nand write.jffs2 20000000 0x80000 0x180000
then:
nand read <memory offset> <nand start offset> <size>
md <memory offset> <size>
so:
nan... | How can I backup Linux kernel image |
1,611,532,540,000 |
Embedded device, Linux version 2.6.26.5, U-Boot 2009.03 bootloader. ARM Linux Kernel Image on NAND flash, loading from NAND.
How to access the filesystem as the root user, and to reset the root password? Is it possible to get this by supplying single boot argument (single-user mode) to Linux kernel via U-boot paramete... |
The correct command for this board is:
setenv bootargs ${bootargs} single init=/bin/sh
(there is no bash installed)
| Access the filesystem as the root user |
1,611,532,540,000 |
I'm working on an existing embedded Linux device and am having trouble editing the partitions using fdisk. My goal is to create a partition for testing purposes on /dev/sda. I am using the fdisk bundled with BusyBox v1.23.2. Please see below for my conundrum:
# cat /proc/partitions
major minor #blocks name
8 ... |
You have a GUID Partition Table (GPT) on /dev/sda, and fdisk, especially early versions or small embedded versions don't work with GPTs. What you see is a sort of "compatibility" output that doesn't show you the real structure, and you won't be able to change partition data with fdisk.
Options:
(1) Take out harddisk, ... | Fdisk does not match /proc/partitions or mount points (embedded) |
1,611,532,540,000 |
I'm currently working on an embedded linux device, i'm trying to make the file system read only which is fairly easy to do, but the application requires read/write access to files in /etc folder (mainly passwd and shadow) those cannot be moved out to the persist partition and linked back to /etc. I came up with a "sol... |
You could look at using the overlayfs filesystem. In a single mount you can superimpose a small readwrite /etc on top of your large readonly /etc, and present a merged filesystem where any changes will be preserved in the upper readwrite layer directory. It is all automatic so you don't need to identify which files n... | Embedded linux read only |
1,611,532,540,000 |
I am prototyping a new embedded system that uses ext4 on Flash memory. These systems will be remotely deployed with no local sysadmin, so any diagnostics must also be done remotely via a network.
The default mount option for ext4 is to set the FS to read only when it encounters an error. I think this is too severe f... |
I would prefer to keep the system running (and tolerate some FS errors)
This is a contradiction in terms. When you get FS errors, your system won't be running for long. In fact, running with errors=continue is very likely to further damage a corrupt filesystem until there is not even any hope of sensible recovery.
I... | Any way to be notified of EXT4 errors when mounted with "errors=continue" |
1,611,532,540,000 |
I have some trouble with a U-Boot mmc hwpartition of an eMMC storage soldered on an i.MX6 embedded module:
TX6UL U-Boot > mmc info
Device: FSL_SDHC
Manufacturer ID: 11
OEM: 100
Name: 004G6
Tran Speed: 52000000
Rd Block Len: 512
MMC version 5.0
High Capacity: Yes
Capacity: 8 MiB
Bus Width: 4-bit
Erase Group Size: 4 Mi... |
Yes — the hardware partitioning is a permanent operation that can only be performed once. You will need to replace your eMMC or get a new board if you want to redo the hardware partitioning.
Hardware partitioning (not to be confused with "normal" partitioning using programs like fdisk) includes:
Going into enhanced... | uboot mmc card already partitioned |
1,611,532,540,000 |
I am trying to test the NAPI functionalities on embedded linux environment. I used 'pktgen' to generate the large number of packets and tried to verify the interrupt count of my network interface at /proc/interrupts.
I found out that interrupt count is comparatively less than the packets generated. Also I am trying to... |
I wrote a comprehensive blog post about Linux network tuning which explains everything about monitoring, tuning, and optimizing the Linux network stack (including the NAPI weight). Take a look.
Keep in mind: some drivers do not disable IRQs from the NIC when NAPI starts. They are supposed to, but some simply do not. Y... | How to test linux NAPI feature? |
1,611,532,540,000 |
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 all tmpfs mounted filesystems are almost empty shmem:448kB
Everyhing is consumed by active_anon pages but running proces... |
Total_vm was badly calculated by me and the OOM report is correct. app has allocated 59739 pages which is 233MB. So, this is the correct reason of OOM.
| Embedded Linux OOM - help with lost RAM |
1,611,532,540,000 |
I'm working on a IMX6 based board, and I need some advice to handle my modem.
I've successfully configure the modem, and mounted the ppp. The modem is working fine and everything's great, but now I want to send him some AT command while running.
Here is the content of my option file :
/dev/ttyACM0
115200
persist
maxf... |
It is not generally possible to send AT commands to a modem while a call is in progress. This applies to all AT-compatible modems, "regular" dial-up modems and mobile phone modems alike, and it has nothing to do with PPP.
By the way, a point of terminology: PPP sessions are not mounted. Mouting and umounting are terms... | Sending command to an already mounted modem |
1,611,532,540,000 |
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. What commands do I type through the terminal to do so? Also, once that is done and the linux is removed, I would like to i... |
There's is not a standardized method to determine the OS and distribution.
The uname -a command is pretty common and works for quite a few Unix like operating systems and often has hints to the actual OS. Linux specific are the /proc/version file and the common lsb_release -a command.
Red Hat and derivative distribu... | Uninstall Linux on an embedded board |
1,611,532,540,000 |
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 for my needs, so i want to switch to other fs like SquashFS or even better not compressing it at all.
Anyways i can't ... |
Make sure you build what ever file system you want directly into the kernel and not as a module.
SquashFS is readonly so you can't use that alone. You may be better off booting from initramfs then loading root from an image, but that's your call.
| Change the root filesystem on an embedded system |
1,611,532,540,000 |
I have a simple embedded setup as follows: x86 target, kernel and root file system built using buildroot. Syslinux is the bootloader configured to boot with an initramfs which points to a .cpio file generated from the buildroot generated root file system. My system boots and works as I am expecting, but I am confused ... |
Any directory path can have any (valid) volume mounted to it. Whether or not /etc/fstab is the correct place to put it depends on whether or not your embedded setup even uses it.
| What happens with /etc/fstab when using an initramfs? |
1,611,532,540,000 |
I am writing an update utility for an embedded Linux device for which I am responsible.
I'm creating a basic side-by-side setup, where updates are applied to a staging partition and then the bootloader is switched to the staging partition, changing the primary partition into the new staging one.
However, the embedded ... |
Create a third, tiny, partition to hold your data. Any other location on your disk will sooner or later bring trouble if indeed you cannot rely on the filesytems.
Sometimes the last few clusters of a disk cannot be addressed in the FAT entry, that may be an option but it heavily depends on exact size of the device.
Do... | Location on disk to write a byte-flag? |
1,611,532,540,000 |
I have a systemd service running on a Raspberry Pi that reads the configuration from EEPROM and converts it into the .env format. This allows other programs to easily parse the configuration later on.
I assume that the EEPROM variable has to be read and parsed every time the system boots and that the .env file needs t... |
/run or previously /var/run would be the most appropriate location.
Systemd itself follows the model of generating temporary configs in /run, specifically under /run/systemd (which would override those in /lib/systemd). For example, your entire /etc/fstab is converted to .mount units under /run/systemd/generator on ev... | Where to place config file created by systemd |
1,611,532,540,000 |
As suggested by Zac Anger, i copy this question over here:
I have a yocto recipe in which I copy/install some stuff to an image. After that, I want to add a line to the /etc/ld.so.conf file like this, so that the dynamic loader finds my library files:
do_install(){
# install some stuff...
echo /opt/myStuff/lib >>... |
I suppose you want that addition in the /etc/ld.so.conf of your target system, but
echo /opt/myStuff/lib >> /etc/ld.so.conf
would change that file on your build host. Fortunally, this gives an error.
Your target rootfs is $D, so your file would be unter $D/etc/ld.so.conf, but more generally, the file doesn't need to ... | How do I edit '/etc/ld.so.conf' in a yocto recipe? |
1,611,532,540,000 |
I need some pointers on how to debug this further.
My setup looks like this:
Hardware: CM3
Pi Firmware boots u-boot, u-boot loads FIT image and is supposed to boot it.
FIT image contains the kernel (uncompressed, ~7MB), device-tree, ramdisk (~2.5MB)
Kernel is 5.15, u-boot is 2022.01
The FIT image loads and verifies ... |
According to your U-Boot ouput, you have an unusual offset of 0x78000 from the start of kernel to the address where the kernel is run:
Load Address: 0x00008000
Entry Point: 0x00080000
The typical case is that you jump into the kernel at the start of the image, so either of the addresses probably has one zero too m... | u-boot/linux hangs after "Starting Linux...." |
1,611,532,540,000 |
Waveshare makes a great CAN HAT for the Raspberry Pi (see here), but the instructions only work for Raspberry Pi OS, not for Armbian. The Banana Pi BPI-M2 Zero has the same pin header layout as the Raspberry Pi, but runs Armbian. How do you setup the Waveshare CAN HAT using Armbian's overlay system?
|
Overlays work slightly differently on Armbian than on Raspberry Pi OS. For this, there are two things you need. First, you need to enable SPI bus zero. This can be done by editing the file /boot/armbianEnv.txt. Add the following two lines to the file:
overlays=spi-spidev
param_spidev_spi_bus=0
If there is already... | Getting a Waveshare CAN HAT working on a Banana Pi BPI-M2 Zero |
1,611,532,540,000 |
I have irq/21-xhci-hcd displayed as the process consuming 90% CPU on top. There was also a lot of CPU time spent on servicing software interrupts (si).
This is on embedded Linux.
Does this mean that it's IRQ 21? Can I then use lspci -vvv to get more info on IRQ 21?
If that's not the case, do I need to use other method... |
xhci stands for eXtensible Host Controller Interface which is standard for USB 3.0 "SuperSpeed" host controller hardware.
irq/21-xhci-hcd is likely to represent the irq associated to one particular usb bus. (Which can host several different usb devices)
lsusb -t utility should give you more information (and lsusb -vt ... | How to get more details on irq process in top? |
1,611,532,540,000 |
Overview
I am in the process of reverse engineering the software on my Infiniti Q50 head unit, and I am trying to figure out the best way to get shell access. I have pulled the image off of the microSD card and flashed it to another microSD that I am modifying, it runs a heavily modified version of Meego which was dis... |
Something like this has worked for me in the past in a similar situation:
Check, if the directory of driver modules contains one or more modules for one of the popular USB-Serial adapter chips
If not, you could compile one of them.Maybe you'll need to cross-compile on a different host architecture
Find/Buy a USB-Seri... | Shell/tty Access via USB or Bluetooth? |
1,611,532,540,000 |
I'm trying to get the WiFi working on a Banana PI M2M using the mainline kernel.
The device tree definition of the banana pi m2m is very incomplete sun8i-r16-bananapi-m2m.dts I successfully managed to get SPI working but I am now struggling to get the WiFi drivers working as they should.
The banana pi M2M uses the AP6... |
I have same board and also want to use mainline Linux.
I found this line in 3.4 kernel log of Banana pi m2m bsp:
[ 14.519605] DHD: dongle ram size is set to 524288(orig 524288) at 0x0
[ 14.535387] dhd_conf_read_others: ccode = CN
[ 14.535623] dhd_conf_read_others: regrev = 0
[ 14.535763] Final fw_path=/lib/fir... | Banana PI M2M (allwinner A33/R16) WiFI drivers in mainline kernel |
1,611,532,540,000 |
I'm working on an embedded device that runs Yocto Poky as distro.
The final product will have several applications that are started by SysVinit. There is only one root user.
I have some scripts, both in /etc/init.d and /etc/profile.d that add some environment variables needed by our applications. The problem I'm fac... |
How can I set the environment during boot (aka without logging in) or let SysVinit doing it, in a nice way?
During the boot environment is clean (isn't initialised jet). You need put env variables via source or . commands for sh (if your service is a script) or initialise it in the program (i.e. via config file).
... | Populate environment in non-interactive session |
1,555,242,594,000 |
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 about 10 seconds or so until I can set it to low with a lirc irsend signal. You can in principle 'overload' the IR-LED... |
Create an udev rule to match it.
It shouldn't be necessary to run the script "after a module is loaded" – it deals with a specific device, so it would be better to run it "after the device is detected". Doesn't matter how the device was detected; as long as the kernel reports it as a 'new' device, it'll work.
That sai... | Run script after module is loaded due to device tree |
1,555,242,594,000 |
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 this about 30 times I get the following and the linux boot completes
mmc0: host does not support reading read-only swi... |
Updating to kernel 4.20 the error no longer appears. I can't determine exactly which kernel commit fixed it. There are a few that might have played a roll, but nothing I could identify as an exact fit.
| mmc0 warning on SD card bootup of linux |
1,555,242,594,000 |
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 commands without reflashing it (and I'm trying to avoid that).
I'm trying to connect the camera to an external machine lear... |
First thing to try is to assign an IP address manually,
ifconfig eth0 192.168.45.1 netmask 255.255.255.0
then use route to make sure that route is also set. Finally do the same on the PC it is connected to, using 192.168.45.2.
Now check with ping if they can reach each other.
If they can't, next step is to figure ou... | IP Camera with embedded Linux won't connect to internet using ethernet |
1,555,242,594,000 |
We are developing embedded device which will integrate with some of our services in future. This device have limited set of functionalities and user defined mods for particular use cases. Based on arm architecture this device running modified version of Debian. For network and main configuration setup I need to write... |
Although this question is a little vague and open to opinion I'll throw mine out there. Golang Has a very easy to use server package right in the standard library. It looks a lot like C, compiles to native executables on almost any platform and architecture and you can host a very simple webserver with very few lines ... | writing small web service for embedded device based on debian [closed] |
1,555,242,594,000 |
I am preparing a new linux kernel for Pine64, because it is slow, I did the cross-compilation on a linux PC.
I am looking for a way to run make install && make install modules without copying the whole ~3GB of source and object files of the compiled kernel over to the Pine64 just to install the compiled binaries.
Is t... |
You can install the modules to an alternate path:
mkdir /tmp/pine64
make modules_install INSTALL_MOD_PATH=/tmp/pine64
Then you can copy the modules from /tmp/pine64, and the bzImage kernel image, to your Pine64.
Another approach is to build a binary package:
make binrpm-pkg
or
make bindeb-pkg
depending on your targ... | Installing a cross-compiled linux kernel on Pine64(or Raspberry Pi or any other similar Single Board Computer) |
1,555,242,594,000 |
I'm building my own Embedded Linux OS for Raspberry PI3 using Buildroot. This OS will be used to handle several applications, one of them performs objects detection based on OpenCV (v3.3.0).
I started with Raspbian Jessy + Python but it turned out that it takes a lot of time to execute a simple example, So I decided... |
In order:
How can I optimize my OS so that it can handle intensive calculations applications and how can control the priorities of each part?
For general optimization, there's not much you can do on the OS side beyond the normal stuff like making sure you have only what you actually need running in the background. ... | OpenCV based programs optimization embedded linux OS [closed] |
1,555,242,594,000 |
Linux version 2.6.26.5 embedded system on board. Device use full Image's Kernel. File system stored on NAND Flash memory, Hynix NAND 32MiB 3,3V 8-bit.
# printenv
baudrate=115200
ethaddr=FF:FF:FF:FF:FF:FF
netmask=255.255.255.0
ipaddr=192.168.1.1
serverip=192.168.1.100
bootfile=firetux.kernel
bootcmd1=setenv bootargs ${... |
You're going to want to be more careful what you do with commands.
The md command shows you memory at that location. When you use md.b it outputs in bytes which no doubt confuses your tty. Your command basically says send me all bytes in memory from 0x01f00000 to 0x01f00000 + 0x80000 over the line. Also nand dumb does... | Backup Nand Flash memory area |
1,555,242,594,000 |
What is proper syntax for setenv bootargs command when using shorthand syntax for method? For example, the full kernel environment variables is
U-Boot> setenv bootargs console=ttyS1,115200n8 rootfstype=squashfs noalign half_image=0 verify=y Hw_Model=pnx8181 Router_Mode=0
I want to add 2 bootargs to the mentioned cod... |
Yes, that syntax should work fine. If you're in doubt, you can double check by running printenv bootargs. By the way, you can also run editenv bootargs which will let you arrow over wherever you want and edit the variable easily. If you're trying to make your change persistent, you need to run saveenv to keep the chan... | Shorthand syntax for U-Boot arguments |
1,555,242,594,000 |
I am working on an embedded linux board with a freescale cpu and an ltib built linux on it. The appliance has two network interfaces and here is the output of ifconfig and route commands:
[root@sina-dwdm /root]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:00:00:00:00:05
inet addr:110.122.5.0 Bcast:11... |
(Written up as answer after confirmation).
Are you sure 192.168.0.0 is a /16 network? If the other machines have it configured as 192.168.1.0/24 (which is more usual), then your 192.168.5.0 on eth1 would just get ignored, and therefore no pings.
Change the netmask to 255.255.255.0 for a /24 subnet on this computer, o... | arp-scan shows machines, but I can't ping some of them |
1,555,242,594,000 |
I have this board with the STi7105BKUD chip on it, along with ram, flash, and a lot of I/O.
Reading the documentation for this chip (here) I can see it has the ST40-300 processor embedded into it ; its doc is right here and says it can run , among other systems, Linux. Architecture is RISC.
Is it possible to succe... |
It definitively is possible to run Linux on this SoC.
Although ST dropped official support and (unfortunately) removed a lot of useful info from STLinux website, a part of it (part of downloads) is available here.
A large number of old satellite and IPTV set-top boxes had STi7105, STi7109 or similar. All of them run L... | Run Linux on RISC STi7105BKUD? |
1,555,242,594,000 |
I am testing a ARM based embedded target running with customized embedded linux version 3.14.
Is there any way that I can find out which scheduling policy my linux is using at runtime?
I see some /proc/sys entries like these on target. But I am not sure whether it is CFS:
sched_child_runs_first
sched_domain/
sched... |
I assume you want to find out if your system is using the CFS CPU scheduler. The scheduling policy is the policy the CFS or some other scheduler uses. On my Ubuntu 16.04 box I have /proc/sched_debug. Maybe you can get a hint out of:
cat /proc/sched_debug
If your system is using the CFS scheduler the output should co... | How verify the current scheduling policy running in a embedded Linux? |
1,555,242,594,000 |
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 for PPP, whereas another is used for GPS.
Occasionally, the 3G modem will stop working and will need to be restarted. I d... |
As it turns out, PPP is affecting it's own serial port, and since that's the one that's used to configure the GPS, that's what's causing the problem.
By comparing the results of stty -F /dev/ttyUSB3 before and after running PPP, it became apparent that PPP was configuring the serial port in raw mode, which meant I cou... | ppp affecting serial ports so that they cannot be used if modem is reset |
1,555,242,594,000 |
What are the advantages of using threads on single core, does that makes sense to use multithreading on single core?
|
There is far too little context here to give a good answer, but for most reasonable contexts the answer is "probably yes". The operating system itself runs many things in parallell on that single core, after all, and you'd be pretty darn annoyed if you had to wait for some web page to finish loading before your mouse ... | Two or more threads on single core [closed] |
1,555,242,594,000 |
My embedded device is not working after updating firmware.
Thus I tried to update firmware using u-boot. I could successfully get u-boot console via serial connection, but updating firmware failed due to the lack of knowledge on firmware update using u-boot.
At last, I not only corrupted linux kernel but also u-boot... |
If available (ie. if there's a JTAG header on your board) , you can connect using a JTAG cable.
Remember: Before using it you might need to enable JTAG using Test Mode Select Input (sometimes a jumper somewhere).
You can then use that connection to upload a new firmware into your device.
| How to recover firmware on a embedded device with corrupted u-boot and kernel image? [closed] |
1,555,242,594,000 |
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, I use dd to copy the new root image (residing on a secondary data partition).
The problem is that half of the times I... |
You're overwriting a mounted filesystem. As soon as the file system driver attempts to read anything from it, you're bound to end up in trouble.
You'll need to make sure that as soon as you're writing the new firmware, nothing else must read or write that partition.
What people usually seem to be doing to circumvent t... | live dd over a mounted read-only root partition |
1,555,242,594,000 |
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 boot I got the following warning, that didn't show up with the initramfs:
WARNING: at kernel/irq/handle.c:130 handle_irq_... |
This is a bug somewhere in the kernel. It is not directly related to rootfs/initramfs changes. It may be due to some other change you made (did you use the same sources, the same configuration, the same compiler?), or it may be related to some timing issue that revealed a latent bug.
This warning comes from handle_irq... | WARNING: at kernel/irq/handle.c - after changing rootfs, but why? |
1,555,242,594,000 |
I have an embedded device, built using buildroot, kernel version 3.6.11 running busybox. The kernel is built with completely default options. I have configured the device according to what the network guy has specified for the IP, gateway, netmask etc and I have put these values in the /etc/network/interfaces file. Wh... |
I managed to resolve the segmentation fault issue which I will document here in case anyone has similar problems in the future. I noticed that when I called the following
ip -f inet addr show dev eth0
instead of
ip inet addr show dev eth0
then the segfault would not happen, but it would still happen with
ip -f ... | Unable to get embedded device to ping anything on the network |
1,555,242,594,000 |
Has anybody ever successfully installed Linux on the Lego Mindstorms NXT Intelligent Brick? I've found plenty of things on Google, but none of them worked.
I can't find the download for legOS, and the gcc I was told to download never actually built (although it spent over 5 minutes in an install script). There was no ... |
AFIAK, only the new Mindstorms EV3 run Linux-based firmware. NXC is only a language and compiler for the Mindstorms NXT, and legOS is an alternative firmware.
| How to install Linux on the Lego Mindstorms NXT |
1,555,242,594,000 |
The below route is sticky, even if manually deleted, it gets added by connmand (Connection Manager Daemon) with another interface name. If the specific interface is made down using ip link cmd, I see the same problem.
root@soc:~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Me... |
connmand appears to be so minimalist and simple that it apparently cannot modify the route specified by DHCP at all.
After a quick browse through the source code, it looks like connmand will set a default gateway to 0.0.0.0 if the DHCP server has specified it that way. Apparently it used to include code to filter out ... | How to configure connmand to not to add the unnecessary route with IP 0.0.0.0 and GW 0.0.0.0 |
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