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I have been working on a Altera DE1-SoC Development Board for 8 months. The system I was working on includes a Cyclone V FPGA chip, particularly the 5CSEMA5F31C6N. It was running an embedded Linux operating system on chip.
All was well and development was on-going. Two weeks ago, a new custom board was put together by... |
Thanks for the reply. This issue has been resolved.
On the development board we are using a 50Mhz oscillator to provide a clock to the HPS peripherals, while a 25MHz signal is generated from that same 50Mhz clock which is then connected to the HPS clock pin on the fabric.
On the new board, we have not used the 50Mhz o... | Why does linux freezes when trying to access peripherals connected to the lightweight hps-to-fpga bridge (or any bridge)? |
1,666,077,107,000 |
I am building an embedded Linux board with Buildroot (user manual here).
I have syslog-ng running on the board. It's config file is specified in buildroot here: https://github.com/buildroot/buildroot/blob/master/package/syslog-ng/syslog-ng.conf:
@version: 3.37
source s_sys {
file("/proc/kmsg" program_override("ke... |
Solved! You must force syslog-ng to reopen its target log files after each log rotation
So, I figured it out. Thanks to @Murray Jensen for the hint about it here.
Whenever logrotate rotates my /var/log/messages file, it renames it to /var/log/messages.1. However, syslog-ng is writing to the file pointed to by the orig... | Buildroot: syslog-ng logs into the "/var/log/messages.1" file instead of "/var/log/messages" |
1,666,077,107,000 |
On a headless embedded computer (booting on a read-only filesystem), I see that systemd-tmpfiles-setup.service is rather slow, and prevents other services to start earlier (I checked with systemctl list-dependencies myservice.service).
How to make it faster on a read-only filesystem?
journalctl -u systemd-tmpfiles-set... |
Since systemd-tmpfiles-setup.service is defined in /usr/lib/systemd/... I used the "masking" technique from the article "Three levels of off":
By symlinking a service file to /dev/null you tell systemd to never start the service in question and completely block its execution. Unit files stored in /etc/systemd/system ... | "systemd-tmpfiles-setup.service" slow on read-only filesystem |
1,666,077,107,000 |
I am developing an esp32 project and I log all the esp32 uart debug output in multiple files. At some point my early releases crash and the output looks something like this:
Guru Meditation Error: Core 0 panic'ed (Cache disabled but cached memory region accessed).
Core 0 register dump:
PC : 0x40008150 PS ... |
sed version:
sed -n -E -e '/^Backtrace:/ {s/Backtrace://; s/:0x3ff[^ ]* */ /g; p}' input.txt
This ignores all lines that don't start with "Backtrace:" and uses two search & replace rules to modify matching lines before printing them out.
The s/:0x3ff[^ ]* */ /g operation matches any text beginning with :0x3ff followe... | How to parse a speciffic strings from multiple files with shell script |
1,666,077,107,000 |
Issue: To reduce the autoboot_timeout parameter in bootloader source code.
Rugged Board---> phyBoard-Segin i.MX6UL/ULL
Current booting time is around 14 seconds and with the autoboot timeout, an extra 3 seconds. Have to reduce the timeout to 1.
Method 1:
@Bootloader:
cd /env/nv
ls
barebox@Phytec phyCORE-i.MX6 Ultra L... |
After much deliberation and digging around I found out. I had forgotten to update the environment in the bootloader for the changes to reflect.
Make the above changes to the file in the path defaultenv/defaultenv-2-base/bin/init
Save the changes.
git status
git add < respective file name in the path >
git commit -m ... | How to make changes in barebox code reflect in build? |
1,666,077,107,000 |
I need to make a Buildroot system for various x86_64 EFI systems with varying storage sizes, but unfortunately, the pc_x86_64_efi config creates an img file with a fixed partition size, not one that expands to the full size of the media it is flashed to. If I want it to fill the various drives, I need to manually spec... |
If you have 'parted' and 'resize2fs' built you can resize the partition, resize the filesystem then reboot in a script.
For example here's a system I'm building with a 500MB image flashed onto a 16GB SD Card:
# parted -s /dev/mmcblk0 u s p
Model: SD SL16G (sd/mmc)
Disk /dev/mmcblk0: 31116288s
Sector size (logical/phys... | How do I create a compressed buildroot system image that expands to fill the available storage of the media it is flashed to? |
1,666,077,107,000 |
I'm setting up an embedded system that is built using the Yocto project. This outputs a root file system, kernel, u-boot, etc. I have an installer script that I run from an SD card that configures the eMMC on the board with partitions, copies in the rootfs, uboot, etc. It produces a bootable system when I boot from... |
User icarus was correct in their comment to my post.
I am issuing the following command from my installation script and that seems to be working:
depmod -b /mnt/root1 -a 4.14.98-imx8mq+gea48c83
The last argument is because the kernel version on the SD card system I'm booting from is different than the system I am mod... | How can I install kernel modules on a mounted file system? |
1,546,427,185,000 |
On an embedded system, we have a a 512Kb static ram on a character device
/dev/mem.
We're currently using it by memory-mapping the file directly in our application with a mmap.
I would like to mount it as a file-system to enable the following use-cases:
manage stored data with system utilities
fast and reliable sto... |
I would consider pramfs: the developers state:
Many embedded systems have a block of non-volatile RAM separate from normal system memory, i.e. of which the kernel maintains no memory page descriptors. For such systems it would be beneficial to mount a read/write filesystem over this "I/O memory", for storing frequent... | What file system to use on embedded static ram device? |
1,546,427,185,000 |
When I use rsync on large files it shows a download speed of 2.7 MB/s, or around 22Mbps. When I run ethtool on the NIC, here is the output
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supported pa... |
Check the Cpu usage through htop while it is transmitting data. If it is maxed out during ethernet events, it is a good sign that your cpu is the bottleneck. The only fixes are to increase the clock of your cpu, or to get a faster one.
| not getting full network speed (or even close) of 100 mbps |
1,546,427,185,000 |
I'm trying to set up a custom Linux installation on an Intel Atom (Baytrail) based Android tablet, using Qt 5.5 for device creation. The build system is based on the Yocto project and builds an embedded Linux image. In order to run this image on the tablet (which is originally and Android tablet), I'm replacing the bo... |
OK, so it turned out the issue was that not all the partitions were being listed under /dev. The eMMC has 15 partitions on, but only 1 - 7 were listed. I thought that the 1 - 7 were just the ext4 partitions, and that the other partitions (which aren't formatted to ext4) just wouldn't show up there. So when I thought I... | Trying to mount ext4 partition from eMMC gives "Invalid Argument" error |
1,436,686,767,000 |
I'm building my own Embedded Linux distro using bitbake . I added udev in the list of dependencies (RDEPENDS).
I noticed that the output of:
udevadm info --query=property --path=/sys/block/sda
is just:
DEVNAME=/dev/sda
DEVPATH=/devices/pci0000:00/0000:00:13.0/ata1/host0/target0:0:0/0:0:0:0/block/sda
DEVTYPE=disk
MAJO... |
The problem is that udev was not started.
/etc/init.d/udev start
Conclusion: in case someone experiences any issue related to udev, firstly make sure it has been started.
| udevadm does not show expected information |
1,436,686,767,000 |
On my embedded system, I can toggle a user led with: echo > 1 sys/class/leds/beaglebone:green:usr2/value.
Similarly, I can find the value of a GPIO (gpio60) (set to input), with more sys/class/gpio/gpio60/value
I've been trying to write a script to set the state of the user led based on that of the input. The followin... |
Maybe like this?
if [ $(cat sys/class/gpio/gpio60/value) -eq 0 ]; then
echo 1 > sys/class/leds/beaglebone:green:usr2/brightness
else
echo 0 > sys/class/leds/beaglebone:green:usr2/brightness
fi
| Basic script in Angstrom Linux running on a Beaglebone Black |
1,436,686,767,000 |
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 schematic revision A1 here link, none of them are mapped to GPIO0_3, which is UART2. But in the dts file, GPIO0_3(on P9_21) is ... |
Angstrom mailing list says this error will be corrected in the next Angstrom release. It can also be corrected by recompiling entire kernel with modified dts file. LCD device tree is bundled with kernel directly and cannot be loaded dynamically like other virtual capes.
| Beaglebone Black Device Tree for LCD4 cape |
1,436,686,767,000 |
Scenario
I am on an embedded Linux system. As usual /var/log/ is the directory when all the logs are stored. I have a directory called /safepath which is created during image creation and it is on persistent memory. It means that whatever I place under /safepath persists across reboot sessions.
I want the logs in /var... |
Not sure if you are still looking for the solution as question was posted 1 year 4 months ago. Anyway, here is the solution that is very simple.
Change configuration file /etc/syslog.conf (or /etc/rsyslog.conf) to change /var/log/messages to desired path.
| How to make /var/log persistent through reboots on an embedded linux device |
1,436,686,767,000 |
I have an embedded system running a custom distro built using Yocto. Later down the line, I will have a usb camera plugged into the system, but for not I would like to use a .mp4 file as a "dummy" camera.
My goal is to stream the video file over USB as a USB UVC device to a computer so that the computer sees my embedd... |
Where to start?
Is of course a very broad question. So, I can only give you a very rough overview:
Linux can, given your SoC actually has the hardware, control an USB peripheral to act as a device (rather than host). In the Linux context, that's called USB gadget.
With that technical low-level functionality solved, ... | Stream MP4 file over usb |
1,436,686,767,000 |
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 ./drivers/usb/serial/qcserial.c but how can I make sure it gets compiled and loaded statically? I can't find it in the kernel config dialog...... |
If you look into drivers/usb/serial/Makefile, you'll see that CONFIG_USB_SERIAL_QUALCOMM is responsible for this driver.
Execute make menuconfig and goto "Device Drivers"->"USB support"->"USB Serial Converter support"->"USB Qualcomm Serial modem"
| how do I include the qcserial module in the kernel? |
1,436,686,767,000 |
Sony has TV, PlayStation, Camera random hardware's. Where many of those have GUI available too.
I want to run my BASH script there with ncurses.
But how do they drive there devices? Which operating system is used inside?
Or they just use micro-controllers or is it open-solaris?
Xperia by Sony Ericsson
http://develo... |
Those customer devices run custom operating systems, or a highly-customized embedded Linux or other UNIX-type OS; sometimes not even Bash and ncurses are included.
It's unlikely that you will be able to run your custom scripts (specially after the PlayStation 3/Linux situation), unless you can get more documentation ... | Sony runs which operating system? Oracle Linux or Crestron Extron or Minix or OS X? |
1,436,686,767,000 |
In the past our company used raspberry pi's for our IOT application.
The problem with that was that SD cards wear out and get corrupt.
We now ordered Compulab SBC's with eMMC storage running Debian.
So what would be the best practices to configure durable embedded IOT devices?
I would say:
Choose an SBC with eMMC sto... |
I'll try to address your first question regarding the storage device durability as I'm a bit familiar with that.
Switching from SD to eMMC might not improve the situation if you don't do an accessment of your system's storage usage and take action to improve things, because both SD and eMMC use NAND.
Do you have an es... | What are the best practices for configuring durable IOT Linux devices? Should I use an Overlay File System? |
1,436,686,767,000 |
I want to install a package manager on an embedded system that does not currently have one.
I know that the best way to do this is to use bitbake to simply bake a new image which includes a package manager and then flash that image to the board, but unfortunately I don't currently have access to all of the necessary p... |
Installing dpkg built for something else on a different distribution to manage software built also elsewhere does not sound like a great idea. This is going to be fraught with binary compatibility problems and subtle errors, as this would be the equivalent of using dpkg with --force-all and disregarding any dependency... | Where can I get a tarball of the debian package manager for aarch64? |
1,436,686,767,000 |
I am running OpenWrt (=Busybox per SSH) so my amount of binaries is limited. I would like to change my MAC address only using a text editor like nano.
|
As you can see here, you should add the option macaddr in /etc/config/network in your desired interface.
For example:
config interface 'lan'
option ifname 'eth0.1'
option proto 'dhcp'
option macaddr 'xx:xx:xx:xx:xx:xx'
After that, restart the network service with /etc/init.d/network restart or reboot t... | How to change eth0 MAC address only using a text editor? |
1,436,686,767,000 |
In the recent project we have been asked to create a debain based system for a SOC. Doing some gooogling I did find guides that point to ways to use yocto to create a debian system [1]. But then I also came across steps to create debian root filesystem using multistrap[2] and it worked (just had to give list of packa... |
The problem may come from the common miss-use of the word Linux. Linux is just the kernel, however it is often used to mean the whole system (kernel, shell, tools, libraries, compiler, and user applications) see here https://www.gnu.org/gnu/linux-and-gnu.en.html it may clear up some confusion.
Debian, Ubuntu, Mint, C... | What makes debian different from other variants given they have same kernel? [closed] |
1,436,686,767,000 |
The motivation behind this question arises from exploring the Intel Galileo gen2 board which has a single threaded processor.
I'm looking for a conceptual explanation on what does that mean for all the userspace applications that rely on the existence of threading?
Does this mean that the kernel needs to be patched ... |
Multi-tasking systems handle multiple processes and threads regardless of the number of processors or cores installed in the system, and the number of "threads" they handle. Multi-tasking works using time-slicing: the kernel and every running process or thread each get to spend some time running, and then the system s... | Multithreaded applications on a single threaded CPU? |
1,436,686,767,000 |
I'm building a control device that runs Debian Jessie on a ARM based Linux SBC. I'm curious what the recommended location is for application files? To date, I've been placing things in a root level directory, e.g.
/MyApplication
But I was toying with moving it to /root/ since it's a single user deployment, e.g.
/root... |
Certainly you have tighter control of the environment on an embedded system than you do on a desktop or server, and you can probably get away with putting your files anywhere you like (subject to constraints like avoiding read-only filesystems, which embedded systems often have).
That being said, I would definitely av... | Where to place application files in embedded linux deployment? |
1,436,686,767,000 |
So I wanted to do some performance test with encrypted and normal data storage on my embedded device.
That is not what I was expected to see at all!
Can you please explain it to me what just happend. Why dd comand output was 1843200+0 records but df -h show file system disk space usage as 13TB?
Maybe I explain what I ... |
You mounted a filesystem existing in /dev/mapper/enc_per_test (the device) to /mnt/enc_per_test/ (the mountpoint).
Then with dd you chose to write to the device, not to a regular file inside the filesystem (i.e. under the mountpoint, e.g. of=/mnt/enc_per_test/blob). Your dd overwrote the majority of the filesystem wit... | Performance test went wrong and the dd command created 13TB of data on /dev/mapper/device. Why system didn't crash? HDD-250GB |
1,436,686,767,000 |
For some reason, my U-Boot does not seem to be able to load files from my FAT32 partition:
=> mmc part
Partition Map for MMC device 1 -- Partition Type: DOS
Part Start Sector Num Sectors UUID Type
1 2048 62519296 a1d1165e-01 0b
=> fatls mmc 1:1
52560 file1.bi... |
It's telling you the reason:
** Reading file would overwrite reserved memory **
Based on the first line of the error message, reading the file into memory using the start address you specified would cause some reserved memory area to be overwritten.
You should either use a different start address (and perhaps rebuild... | Why am I not able to load files from a partition with U-Boot? |
1,436,686,767,000 |
We have IoT gateways that run Linux 5.4.31 kernel. These gateways need to manage thousands of devices which are mobile and each has a unique encryption key. The idea is to fetch the key of a device from a server (via secure channel) when the device enters the range, use it for decryption as long as the device is in th... |
You’ll probably get better answers on Information Security SE.
You should ensure that the keys aren’t written to swap, by locking the relevant memory ranges (see mlock); this is easier to do if you allocate a pool of memory for the keys.
Also what restrictions should we put on a non-root user, e.g. they can't access ... | Feasibility of storing keys unencrypted on RAM under certain assumptions |
1,622,818,609,000 |
I want to know what actually happens once I turn my ethernet OFF.
What does the OS do on a network layer?
Does it flush the routing table or anything like that.
|
Linux kernel describes every Ethernet adapter(physical device or virtual) by struct net_device (struct net_device). Every struct net_device has a set of struct net_device_ops which should be implemented by device driver. The most important of them:
ndo_open(). Called when you set Ethernet adapter to ON (ip link set u... | What happens when I turn my ethernet off? What steps does the OS perform once I turn the ethernet OFF? |
1,622,818,609,000 |
I am usin Buildroot as distro.
I have a problem. I wanted to update my build with adding some packages for my embedded system(stm32mp157).
In menuconfig --> Filesystem images I chose an exact size of 270M which generated the above error.
I tested the exact size and I for
exact file size inferior to 265M :mkfs.ext4: Co... |
I assume you are using genimage to create your final SD/MMC image. If this is the case, then your genimage configuration file defines a size of 256 MB for the partition that holds the rootfs, and this size is too small. You need to change your genimage configuration file.
Based on the issue you report, I suppose you'r... | Buildroot How do I deal with Error filesystem size (BR2_TARGET_ROOTFS_EXT2_SIZE) |
1,622,818,609,000 |
We have an embedded arm device running an OS based on Debian 9, running kernel 4.14.67-1.0.6+.
EDIT: As per @A.B's request, below is the driver/chipset info too for future viewers - I didn't know how to find this at the time of asking the question.
filename: /lib/modules/4.14.67-1.0.6+/extra/mlan.ko
license: ... |
I also asked the device manufacturer if they had any suggestions a few days ago, while it took a bit for them to respond, their suggestion appears to be working perfectly.
The basic /etc/network/interfaces that I have is fine, but there was 1 line that I was missing when I was trying all the various options in /etc/wp... | Embedded device wpa_supplicant reconnect |
1,622,818,609,000 |
I have an issue trying to build kernel and modules for an embedded system. The resulting Module.symvers has some (a few dozen) entries with invalid (0x00000000) CRC entries.
I'm trying to figure out the process by which Module.symvers is generated so that I can start debugging the problematic entries. However, after l... |
The creation of Module.symvers has a number of steps. These steps make use of MODVERDIR (typically .tmp_versions in the build directory) which contains .mod files,
After the modules are compiled and corresponding .o files are generated, the source is pushed through the C pre-processor with -D__GENKSYMS__ and the resu... | How is Module.symvers generated? |
1,622,818,609,000 |
I am working on embedded Linux.(arm)
I am using mplayer.
In general, the video plays well. (# mplayer aaa.mp4)
However, using the "-zoom" option will slow video playback. (# mplayer aaa.mp4 -zoom)
Why is it slower with the "-zoom" option despite the same movie size?
How should I solve this problem?
|
man mplayer:
-zoom
Allow software scaling, where available. This will allow scal‐
ing with output drivers (like x11, fbdev) that do not support
hardware scaling where MPlayer disables scaling by default for
performance reasons.
Solution: use video output which support... | The "-zoom" option slows down mplayer |
1,622,818,609,000 |
I am working on ROS under Ubuntu 14.04 on an Odroid XU3 (ARM dev board).
I connect two USB devices to my dev board which are recognized as ttyACM0 and ttyACM1 according to the time when they are connected.
Since thoses devices (Arduino & PixHawk) have different PID / VID, I would like to bind them to a certain "custom... |
Your configuration should basically work, but I'd like to make a few suggestions:
First off, I think you want to use ATTR, not ATTRS. ATTRS searches the whole device tree upwards to a matching (parent) device. This is most likely not what you intend. With using ATTR the device actually triggering the event has to h... | How to give a custom name to a serial device on connection? |
1,622,818,609,000 |
I'm new to embedded and am reading 'Embedded Linux Primer' at the moment.
I tried to build an xscale arm kernel:
make ARCH=arm CROSS_COMPILE=xscale_be- ixp4xx_defconfig
#
# configuration written to .config
followed by the make:
~/linux-stable$ make ARCH=arm CROSS_COMPILE=xscale_be- zImage
make: xscale_be-gcc: Comman... |
I'm reading the same book and get stuck in the same part, so... after some research i finally compiled the kernel for ixp4xx target
Download the ARM toolchain from:
Devloper arm Compiler v6
then...
$ mkdir -p ~/opt
$ cd ~/opt
$ tar xjf ~/Downloads/gcc-arm-none-eabi-6-2017-q2-update-linux.tar.bz2
$ chmod -R -w ~/opt/g... | make: xscale_be-gcc: Command not found |
1,622,818,609,000 |
I try to speed up my boot sequence, and somebody recommends to use the uClibc instead of Glibc. I've built an image with it, it gets smaller and faster to boot — but at which cost?
Does anyone know the disadvantages of using uClibc as the C library?
|
You can refer to the official page: https://www.kernel.org/pub/linux/libs/uclibc/Glibc_vs_uClibc_Differences.txt
| What are the disadvantages of uClibc? |
1,622,818,609,000 |
I am working on an embedded Linux system (kernel-5.10.24). Now I am trying to use zbar-0.23 to scan barcodes in JPEG format, but I don't know how to do that.
There is an example/scan_image.c, which can scan barcodes in PNG format, but my barcodes are all in JPEG format.
So how to scan the barcodes in JPEG format with ... |
The zbarimg program uses imagemagick to read the images.
See the code here: https://github.com/herbyme/zbar/blob/068c810f75994b61ab9edc689650d09a0fc78bf9/zbarimg/zbarimg.c#L127
That deals beautifully with jpeg and a very large range of image files (unless you disabled jpeg explicitly when building imagemagick). So, I ... | How to scan barcode in JPEG format with zbar in Linux? |
1,622,818,609,000 |
I have to update some outdated embedded systems. But the RAUC Update contains four partitions, while the old systems have only three partitions.
The additional Partition is at the start of the disk and I cannot flash the devices with an external Adapter.
What I have, is SSH access to the existing Linux on the device.
... |
I did something similar on an embedded system. What saved me was that the compressed image of the new disk (with all its partitions) was small enough to keep in memory.
What I did was to patch the initramfs to include a custom script. At boot, before mounting anything, it copied the (compressed) disk image into a ramf... | Handle Partition Changes Embedded System |
1,622,818,609,000 |
I am trying to ssh into an embedded Linux device (let's call it petalinux) connected to my Ubuntu server running 22.04 (let's call it oip). petalinux and oip are connected by a direct ethernet cable and a serial UART. I am able to connect to the device using a serial terminal (minicom), but ssh times out. I am also un... |
With 192.168.0.10/24 already set on petalinux's eth0 linked to oip's eno1, to allow communication between oip and petalinux, run this on oip (as root user, meaning it probably should be prepended by sudo ):
ip addr add 192.168.0.11/24 dev eno1
And that's it: each should now be able to reach the other using the other'... | Unable to ping or ssh into embedded Linux device: eno1 has no IPv4 address |
1,622,818,609,000 |
I'm basically trying to read the output of the below command in my c application.
timedatectl
so basically I wanted to read the RTC time through my application so for the same reason I was trying to read the output of the above command in my application.
O is there any other way to read the time from the RTC by using... |
If you want raw access to control /dev/rtc0 then you need to use the ioctl call after opening the file (as per manpage), e.g.
#include <errno.h>
#include <fcntl.h>
#include <linux/rtc.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <time.h>
#include <unistd.h>
int main(int argc, char** argv)... | How to read rtc driver data (dev/rtc0) from embedded c application? |
1,622,818,609,000 |
I'm trying to send a binary packet to a local process, via netcat (nc), like this:
nc -w 1 -u localhost 10000 < my_binary_packet.bin
The output is:
read(net): Connection refused
Anyone know what's going on?
I get the same result with nc -w 1 -u 127.0.0.1 10000 < my_binary_packet.bin
|
Summary
If your listener is bound to a particular IP (such as 192.168.0.10) and port (such as 10000) instead of to IP INADDR_ANY (Internet Namespace Address Any, which means it listens to all interfaces / IP addresses), do this instead to specify the correct IP:
# with netcat
nc -w 1 -u 192.168.0.10 10000 < my_binary_... | "Connection refused" when I try to send a UDP packet with netcat on an embedded-linux board |
1,622,818,609,000 |
I'm developing an embedded board (Tinkerboard) based on Linux Linaro (Debian) OS 9.3.
The board is basically a (webpage) kiosk where the browser is run by a sh script included the automatic scripts on startup. The kiosk needs to play a couple of mp3 files triggered by js events.
Most of the times the audio is not repr... |
This seems exactly the kind of problem a sensible init system solves:
Starting services and programs in the right order, and exactly when the things they depend on are ready; not earlier, and not a fixed 4s seconds later than the last start, "just to make sure".
On Debian 9, you'd use a systemd service to initiate the... | How to wait for pulseaudio before running chromium? |
1,622,818,609,000 |
How can I customize systemd source code? When I do bitbake, systemd appears in my end project, but I cannot find any source files of it in my local directories. I want to track down unit files lifecycle, log_debug(...) and log_info(...)s are not showing up (some of the messages appear, but gives not enough info for me... |
Besides adding recipe name to the RM_WORK_EXCLUDE += "systemd" in local.conf, one should clean shared state using one of the cleaning options provided by Yocto, for example $ bitbake -c cleansstate recipe before bitbaking again, otherwise, with an unflushed shared state cache it will start from the current state, not ... | How Yocto embeds systemd in end project? |
1,622,818,609,000 |
I have a wokring image file for an ARM embedded Linux system.
The rootfs partition is way too big and I want to shrink it.
Initial scenario:
Disk /dev/loop0: 7,22 GiB, 7744782336 bytes, 15126528 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optima... |
This is probably because the partition type is a2.
A2 Hard Processor System (HPS) ARM preloader
This partition type is used for bootable images of ARM-type computers.
For a normal Linux system that uses an x86, you should be able to delete this partition.
----edit----
Because this is ARM, it is the preloader image. ... | Moving the third partition might prevent the boot of os |
1,622,818,609,000 |
So I recently acquired Ingenic SoC based RS-97 game, which runs MIPS instruction set. The vendor vaguely provided instruction on how to compile the linux kernel for the target SoC. So based on vendor instructions and online search the following are needed to have an image of the embedded linux for the platform.
Com... |
These are very big questions, I'll try to summarize as simply as I can.
why root file system is separate from kernel image?
The kernel image is an executable provided by kernel.org (you can modify it if you want but most people don't) which provides the framework for your embedded Linux project.
The root file system... | From Compiling Embedded Linux Kernel to Generating Image for Target Platform |
1,622,818,609,000 |
I am trying to boot the kernel with the nfs root file system. I am suspecting that some memory issue is there. I have a kernel version 4.12.28. This version has a lot of cache changes. I am suspecting that the kernel memory is not initialized properly. This build is using Yocto Sumo with DTC version 4.7. This is a pow... |
That looks like the kernel is getting an illegal instruction exception (700 is a Program exception - which can be a number of things, but sig: 4 is SIGILL).
There are a number of unimplemented instructions in the e300 core - double check the compiler you are using to build the kernel is correct and using the right com... | Power PC TRAP - 0700 - Kernel Memory Issue? |
1,622,818,609,000 |
I wonder how design permissions in root file system should look for embedded device, with busybox onboard (buildroot environment). Several ordinary users may login to the system using ssh.
My initial concept is to remove all permissions, except x, of group (root group will be accessible by admin) and others for /etc,... |
It sounds like you already know enough to choose a permission design for /home/user1, or equivalent. You're asking about the rest of the system. There are already a few discussions here, at least on a related topic:
Limit a user to his own home directory
Allow user to connect using SSH or SFTP but limit to home dir... | Rootfs permissions design |
1,622,818,609,000 |
I am building a customized kernel for RPi. The problem is that the RPi bootloader requires a vfat /boot partition whereas I intend to minimize the kernel size, so need to remove vfat support from kernel.
I have read Embedded Linux Primer and Linux Kernel Development books. From what I understood, it seems that /boot p... |
systemd will try to mount the filesystems you have listed in /etc/fstab, so if you remove /boot from /etc/fstab it shouldn't try to mount it.
(I just tested this on a Fedora system, removed it from /etc/fstab and confirmed it wasn't mounted.)
systemd does have some code to treat EFI partitions specially, so maybe that... | Build kernel without support for /boot's file system |
1,622,818,609,000 |
I have an embedded system with 3 operating systems (self-created Debian 9.4 with 4.14.40-rt Kernel). Each operating system is on a different partition. A bootchooser sets up the system so that when one operating system does not start, the next one is started. Furthermore, this Bootchooser can also provide these 3 part... |
Welcome to the Unix & Linux StackExchange.
systemd does not support /etc/ on a separate partition.
Your next best option would to be sync key files between the 3 operating systems.
You might follow the pattern of etcd and have a central repo that all 3 OSes sync from. You'll have some bootstrapping problems to deal w... | Get same /etc in different Operation Systems |
1,622,818,609,000 |
There's plenty of barebone PCs/servers optimized for building custom Linux/BSD based routers, VPN servers or firewalls and in general various L3 devices. However I couldn't really find anything about L2 devices with hardware switch ASICs. While I know it's possible to just use bridging it's not really practical solut... |
Try the term whitebox switches for your searches. There are some vendors/distributions in that area.
| Are there any network switch platforms for Linux/BSD? [closed] |
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I am running u-boot on a Beaglebone Black custom install, and have modified ./include/configs/am335x_evm.h to set the default bootdelay to 0, which was working well when I was loading my kernel and device tree off of a fat partition. But I switched partition 1 from fat to ext4, and change the fatload statements in my... |
Download the ARM cross-compiler GCC on your PC.
wget -c https://releases.linaro.org/components/toolchain/binaries/6.4-2017.11/arm-linux-gnueabihf/gcc-linaro-6.4.1-2017.11-x86_64_arm-linux-gnueabihf.tar.xz
tar xf gcc-linaro-6.4.1-2017.11-x86_64_arm-linux-gnueabihf.tar.xz
export CC=**/path to**/gcc-linaro-6.4.1-2017.11... | u-boot bootdelay=2 when booting ext4, and bootdelay=0 when booting fat |
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I am trying to port a software on aarch64 Linux. One of the requirements of the software is perl-Net-IP library package. When I try to search for the source code of perl-Net-IP package, I get Net-IP package. Are they both same?
|
Net::IP is a Perl distribution, that you can find on MetaCPAN, you have a link in the left toolbar to download it.
When it is packaged by some Linux distribution, the name of the distribution package can be perl-Net-IP or libperl-net-ip or other variations. Hence it depends on the Linux distribution you are using the ... | Is perl-Net-IP package same as Net-IP package? |
1,622,818,609,000 |
I'm currently trying to boot an Atmel Sama5d2 Xplained evaluation board from NFS server.
I'm running a Debian 9 with 4.9.0 kernel version and the nfs server is nfs-kernel-server.
Here is the NFS server configuration
/srv/tftp/xplained/rootfs *(rw,nohide,no_subtree_check,async,no_root_squash)
My NFS server succesfully... |
Thanks to @alanSchmitz and after some investigations, I finaly found where the problem came from.
Apparently I have to force the use of NFS v3 inside uboot by specifying it on kernel boot arguments as follow root=/dev/nfs rootfstype=nfs rw nfsroot=<server_ip>:/srv/tftp/xplained/rootfs,vers=3
I have tried to fix this ... | NFS boot fail on Atmel Sama5d2 xplained |
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I am trying to bootstrap and configure an embedded system. I need to enable certain systemd services (e.g. networkd, resolved).
I'm working on an x86* machine while the one that I'm configuring is an ARM machine - so I (presumably) need to use the host's systemd to edit the systemd configuration stored in the ARM's f... |
Just create the symlinks that systemctl enable would create. There's not more to it then that.
| Configure systemd in mounted root (i.e. offline) |
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I use u-boot 2014.07 from denx git repository in our board. This u-boot gives me after compilation two files : u-boot.bin and MLO. MLO is first bootloader. I put both on sdcard first partition formated as FAT32.
When my board - chiliboard from grinn company - boots, SPL runs and writes 'C' many times with 1s delay. I ... |
I've found an answer here -> https://e2e.ti.com/support/arm/sitara_arm/f/791/t/471656
Problem was wrong SYSBOOT settings. ROM was waiting for SPL to be sent via the serial port and producing the 'C's as part of the X-MODEM protocol.
| Disable waiting and writing 'C' in u-boot SPL? - am335x, u-boot v2014.07 |
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Information about mtd partitions can be passed to the kernel via the kernel command line (mtdparts parameter) or via the device tree.
Is it possible to override this after the kernel has booted?
|
No.
del_mtd_parttions is called only during cleanup. There is no path where it is called prior to re-adding different partitions.
| Override mtdparts after kernel has booted |
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A router runs firmware containing BusyBox and in addition to flash memory the device has secondary memory storage. That USB stick is mounted at both /media/Main and /opt:
# mount | grep sda
/dev/sda1 on /media/Main type ext4 (rw,noatime,data=ordered)
/dev/sda1 on /opt type ext4 (rw,noatime,data=ordered)
Duplicates in... |
Where to export
After having read https://bitbucket.org/padavan/rt-n56u/wiki/EN/UsingCron a good way to export configuration variables for both crontab and shell usage, is to insert the /opt related variables into /opt/etc/profile.
Where and how to source
To use ("source") the variables in cron it is suggested to:
cr... | How to “export” configuration variables and "source" them on embedded Linux? |
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I am working with a board and when it finishes the boot, it gives us login as root user. What I want to do is to login as user or root based my requirement. Mean when the board boots up i should get a prompt which allows me to login as either root or login as user.
How can i go about this.
# Startup the system
null::... |
Make sure your user and root have passwords; as root, run:
passwd user
passwd
(replacing user as appropriate). Once you've done that, you can replace
console::respawn:/bin/sh -l
which starts a shell directly, with
console::respawn:/bin/login
if you have /bin/login on your system.
Traditionally you'd use getty to ma... | Enable user login, there by login can happen either as root or user based on requirement |
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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 my kernel:
CONFIG_NET_IPGRE_DEMUX=y
CONFIG_NET_IPGRE=y
CONFIG_NET_IPGRE_BROADCAST=y
There is not gre0 interface when int... |
The problem was GRE demultiplexer module required by ip_gre. When kernel loads GRE demultiplexer driver registers protocol 47 handle so when ip_gre.c attempted to do the same it fails because it has been registered before. It is solved by modifying ip_gre.c to not register protocol GRE handle.
| GRE supported in kernel but iproute2 cant create GRE tunnel |
1,394,917,817,000 |
On my embedded device, I have this error showing up after kernel boot:
init.exe: Caught segmentation fault, core dumped
But I cannot understand why is this happening? If I do battery cut( i.e. reboot my device foricbly) then the device boots and comes up fine.
Any pointers will be extremely helpful. Is this some tran... |
The output mentions it dumped core. Try doing:
gdb -c [corefile]
Then at the (gdb) prompt, do:
(gdb) bt
To get a backtrace. If the binary was not stripped, you might be in luck and at least have something to google for :-)
PS: The core file might be core.PID, where PID was the PID of init.exe when it died.
sc.
| init.exe: Caught segmentation fault, core dumped - what is the source of this error |
1,394,917,817,000 |
I am trying to create Linux input device driver and to test things I took at existing gpio-matrix-keypad driver. Using print I know that input_report_key() is called with correct keycode, but it doesn't put a correct character under the cursor.
pr_info("Print: %d\n", keycodes[code]);
input_report_key(input_dev, keycod... |
As we've discussed, the expected keys are inserted to the input subsystem correctly. They aren't getting to you via your serial connection and that's actually what should happen.
See, when you use serial connection, input and output for /dev/console come from /dev/ttyS* instead from a keyboard and a screen. This means... | Keypad driver does not input character with input_report_key() |
1,394,917,817,000 |
I have made a custom Linux image with Yocto for use with CN0540 and DE10-Nano. The manufacturer of the CN0540 (Analog Devices) provides an evaluation image for the board, which works without issue, however in my custom image which is using the same kernel fork (ADI Linux fork), the same defconfig as far as I can tell ... |
Finally, found a solution.
U-boot needed to have some handoff files generated.
$ python ./arch/arm/mach-socfpga/cv_bsp_generator/cv_bsp_generator.py \
-i <path_to_qpds_handoff>/hps_isw_handoff/soc_system_hps_0 \
-o board/altera/cyclone5-socdk/qts/
Docs for this are in the /doc/README.socfpga file.... | IIO Unable to refill buffer: Connection timed out (110) error when running iio_readdev |
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I am using Debian desktop for Lichee Pi and I am new this platform(linux). I communicate serial with lichee pi using putty. I made the lichee pi connection with the keyboard using microusb to usb converter, but my keyboard is not working. How can I solve this? My setup looks like this:
|
after use a micro usb to usb converter, it worked. I think female-female usb cable is not supported for this ecosystem
| I can not use keyboard for Debian |
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Depending on the detected hardware I need to start one of two executables of psplash with different images, so in my psplash_%.bbappend I have
SPLASH_IMAGES = "file://bootscreen1.png;outsuffix=type1 \
file://bootscreen2.png;outsuffix=type2"
And if I bitbake it, I find a psplash-type1 and psplash-type... |
Okay, I found out myself and I'll answer it myself, because I couldn't find the answer anywhere in the web:
By giving outsuffixes other than default, you create separate installables to be included separately in the image recipe
IMAGE_INSTALL_append += " \
psplash \
psplash-type1 \
psplash-type2 \
"
This is e... | yocto: psplash custom executables do not get installed |
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I have a small cpp application which will reboot the system. This works very well so far.
sync(); //need for data safety
reboot(RB_AUTOBOOT);
Unless you are connected via SSH and run this program on the connected device. Then the SSH connection hangs.
If you are connected via SSH and use the CLI commands
sudo reboot
... |
The Solution is to use kill(1, SIGINT) instead of reboot(RB_AUTOBOOT)
More details in https://stackoverflow.com/a/69042761/6729765
| SSH session does not get terminated with cpp reboot comand |
1,643,747,634,000 |
I am trying to convince a sound card to work on a custom HW similar to an Avnet ZED Board.
The original driver example was based on a heavily (a patch to vanilla is about 180k lines) modified 3.14.12 kernel and was called zed_adau1761. The "sound card" is not handled within one driver, it is divided into three logical... |
An attitude to SoC drivers has changed over the years in a way.
The support to OF (Open Firmware - in other words for configuration in device tree) has been reworked, improved and extended in the area of sound card drivers.
It's preferred to use a general solution instead of writing a number of machine drivers (the "g... | (The lack of) ZED board sound card support in GNU/Linux |
1,643,747,634,000 |
I have the U-boot image called:
rootfs.13cy.initramfs.bzip2.uboot
I want to see what's inside of it.
Whats dumpimage cmd shows me:
dumpimage -l rootfs.13cy.initramfs.bzip2.uboot
Image Name: Ramdisk Image
Created: Sun Oct 25 00:39:27 2020
Image Type: ARM Linux RAMDisk Image (bzip2 compressed)
Data Size: 1... |
You can uncompress the image with bzip2. Read man bzip2.
You can mount the uncompressed image with mount's -o loop option, read man mount.
| How to unzip the U-boot image? |
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I've configured my busybox in menuconfig and made it as a static binary (no shared libs) + forced no MMU build.
I'm using the prebuilt arm cross compiler and when I enter the below command, it gave me error while building the source code.
sudo make -j8 ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-
it gave me this log:
... |
Use Linaro arm toolchain instead of glibc. the default arm gnu compiler on ubuntu is not stable.
https://releases.linaro.org/components/toolchain/binaries/latest-7/arm-linux-gnueabihf/
| cannot cross-compile busybox for arm |
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I want to create a image file that contains two partitions:
100MB FAT Boot partition that contains my kernel zImage and dtb(device tree blob) files.
900MB EXT4 Rootfs partition that contains my root file system.
Then I want to be able to flash that image file to any sdcard to boot may linux board.
How can I do this ... |
It's an easy task! Just follow these 15 steps.
steps:
Allocate a file space with fallocate -l 500M sd.img.
Use fdisk(dos partition table) or gdisk(gpt(guided partition table)) to create partition table sudo fdisk sd.img.
After opening fdisk, create a partition by pressing n and then press p to create a primary partit... | How to create linux sdcard image? |
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I want to boot uCLinux on the stm32f4 but I don't have enough knowledge about Barebox. is it possible to port Barebox for cortex m4? if yes, how?
|
The short answer is no. but the barebox community is working on it to bring barebox to cortex m devices too. I suggest you to use u-boot for now because it supports many cortex m socs (m3, m4 and m7).
you can easily port barebox for any cortex m mcu. you can use u-boot drivers to port them to barebox.
you must have a... | does Barebox bootloader works on cortex m4? |
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On an embedded system, we need to boot a Linux partition in several "flavors":
an operational mode where sensitive services are disabled (e.g. sshd);
an integration mode where such services are enabled.
The expected process is to detect specific GPIOs signals at startup.
The bootloader is U-Boot, and already reads t... |
Are there any drawbacks to the "kernel argument" solution ?
I don't think so.
Did I miss any other simple solutions ?
I would go on the kernel solution and use a specific runlevel.
If i understood well your needs, the integration mode will implement the same things than production/operation mode but with stuff add... | Booting Linux with different security configurations |
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I am setting up an embedded linux device which should grab its IP-address and its MAC address at boot from files in the filesystem. Lets say there is a file /root/ipaddress with the only content "192.168.10.10" and /root/macaddress with "02:02:02:02:02:02" . The rest of the configuration should not be configurable.
Cu... |
ifupdown set of scripts isn't designed to work that way.
Instead, you may:
Stop using ifupdown and manage to configure the networking by yourself inside a dedicated script. (i would probably choose this option)
Use the post-up feature of ifupdown, that way:
iface eth0 inet static
pre-up ifconfig eth0 hw ether `cat... | Alternative way to configure IP address |
1,643,747,634,000 |
I am on a custom board using an i.MX6. I am using Yocto (Pyro) to build my kernel (4.14.16).
I am using the generic imx6qdl.dtsi device tree entry for PWM2 to drive the fan and it appears to work fine. The fan has a Tachometer input, which is connected to GPIO2_7. How do I read the fan speed? I have seen device ... |
I was unable to find a device tree solution, but found enough code snippets to make an application to read it. Basically I just set up an interrupt on the GPIO and used clock_gettime to measure the period between edges. It requires a lot of filtering, but I am only using it to make sure the fan is running so that is... | How to read back a fan speed? |
1,548,861,490,000 |
I'm confused about the partitions size of a flash memory in my embedded linux device:
/ # cat /proc/partitions
major minor #blocks name
240 0 93184 ndda
240 1 85168 ndda1
240 2 7000 ndda2
240 3 1000 ndda3
I know the partitions corresponding to ndda2 and ndda3 w... |
Partitions are generally started on a boundary of 2MB to align the filesystem blocks with the physical blocks (which may be 16kB, 64kB or even larger, depending on the device). Misaligned blocks mean that when one filesystem block is updated, two device blocks need to be fetched, the last part of the first block gets ... | Interpreting /proc/partitions |
1,548,861,490,000 |
I have an embedded linux system that has limited commands available. VI being the only text editor I found so far. I can run SH to run a script but again, limited abilities.
I need to ftpget a text file from a remote address, read said text file, then update a specific line that starts with syslocation in a different... |
Check if you have vi configured to be able to be invoked as ex, which sounds exactly what you want. ex is vi in non-interactive mode. See the answer here: https://vi.stackexchange.com/questions/457/does-ex-mode-have-any-practical-use
See also the answer here for practical examples: https://vi.stackexchange.com/questio... | Embedded linux to read text and append it to another file [closed] |
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I'm trying to interface LCD for my new WaRP (imx7s-solo). (we can found both LCD and WaRP7 here LCD and WaRP7 product) The problem is I can not have enough knowledge to verify my work is right or wrong. (I'm an application developer actually...). My work are below:
First try: I build & install core-image-sato on board... |
I am currently working on the LCD Display integration on the WaRP7, and it's working well but not yet merged on the linux-warp7 kernel. I maintain the official Yocto/OE layer for WaRP7 (with some examples), and there are some features for LCD have been already merged.
I just opened a pull request to push the unofficia... | How to interface LCD for new WaRP7 (imx7s-solo)? |
1,548,861,490,000 |
Recently I tried to make my own cross-compile toolchain for a arm platform. I noticed with the autoconf script of GCC, I have to pass variables like:
--with-cpu=cortex-m4 \
--with-fpu=fpv4-sp-d16 \
--with-float=hard \
--with-mode=thumb \
So it seems different ARM platforms should have different tool chain/compiler ca... |
When building the toolchain itself, you have to configure which features to support. You can build a "slim" compiler, supporting just the features you need for the target you want.
But you can also support everything the ARM platform has to offer and get a clumsy compiler.
For the features themselves, you should diffe... | Does ARM platform have a universal tool chain / compiler? |
1,548,861,490,000 |
I am trying to build a embedded Linux system for karo imx6 8033 som with 4GB SD card on it by using buildroot to build rootfs, Configuring kernel 4.11. I am using mfg tool to write the system on module. After flashing the SD card, I see that rootfs partition is just 300MB.
# df -h
Filesystem Size U... |
I find the solution.
In my case, I have chanced script named ucl2.xml file in Profiles/TX6/OS FIRMWARE in MFG Tool file. karo TX6 board has 4 GB MMC, so I made changes under "LINUX-MMC" In line 104
<CMD state="Updater" type="push" body="$ [ -b /dev/emmc ] && (echo label-id:0x0cc66cc0; echo size=30720,type=c; echo ... | Partition for embedded linux before flashing the SD card |
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I am working on an embedded system built around Atmel ARM926EJ-S based on rather old ARM core ARMv5TEJ. I have a Debian 8 system that used to work for that hardware until I had to update the kernel from 3.11.6 to 4.1.18. The update was needed in order to add support for certain USB hardware.
The update gave me what I ... |
I tried kernel version 4.11.0 which is the latest stable version at the moment, as suggested in the comments to the question. There were some new options regarding reboot and it works now.
I didn't investigate the details further so I can't tell whether something had been broken and then got fixed again or if version ... | How to fix reboot broken by kernel update |
1,548,861,490,000 |
An embedded device, running eCos OS, with FTP Lite Client. I want download file from device to local PC via FTP during terminal session. FTP transfer initiates device, it ask to specify the FTP IP address, file name, user name and password. Once details entered, it starts FTP transfer. Device not allow connect FTP cl... |
How to setup FTP application on Ubuntu for this purpose?
You need an FTP server that will allow uploads.
I recommend vsftpd; here is a page that explains how to configure it for upload:
https://www.centos.org/forums/viewtopic.php?t=39485
| FTP download question |
1,548,861,490,000 |
I have a small device that runs a light weight embedded linux. I can telnet and ssh to the device. This device has no package management utility on it that I can tell.
I am trying to install a pre-compiled audio recorder such as LAME, however I am having a hard time getting details on this device to find a package th... |
Passing the commands below as root will give you an overview of the device's hardware and the kernel and drivers running on the device, maybe the name of the distribution too.
uname -a
dmesg
cat /etc/issue
cat /etc/lsb-release
The current LAME source code can be obtained from https://sourceforge.net/projects/lame... | Embedded Linux Distribution |
1,548,861,490,000 |
I have a linux media player that was very common before android's age. It is a MIPS running Linux Venus 2.6.12.6 and has 2 sata, 2 usb and 1 sdcard port. Since the flash memory is very limited, I installed optware, ssh and nano on sdcard and put in
ln -s /tmp/usbmounts/sdb1/opt /opt
The sdcard can remain plugged for ... |
Better to explicitly say that this is a shell script and I wish to use ${@} instead of $*:
#!/bin/sh
mount -o remount,rw /
echo ${@} >/tmp/log.txt
echo >>/tmp/log.txt
env >>/tmp/log.txt # if /tmp is writable or tmpfs
exec /sbin/sbin/hotplug "${@}"
If the system is sane, this should work. Many embedded, however, are n... | Embedded linux hotplug changed mount point |
1,548,861,490,000 |
I'm working on a embedded system. I have multiple SD cards to save copy of Linux rootfs on (kernel saved in nand). On a original SD card, where is located a system, and from this card the system is copied to another - everything works nice. Init service is working as it should.
But there is a problem on copied system ... |
Had to do some copy/paste things. First, I've downloaded minimal ELDK distribution (i'm using it), copied all with rsync. Next i've rsynced copy of system and copied it on SD card on fresh system. All worked.
| Embedded Linux and Init problem - Init won't start |
1,548,861,490,000 |
I am trying to boot linux from flash on an powerpc board. In u-boot I set bootargs with:
setenv bootargs root=/dev/mtdblock1 rootfstype=ext2 rw console=ttyS0,115200 ramdisk_image=\${rd_size}
I also tried rootfstype=ext3 and jfs2; and root=/dev/mtdblockn (n from 0 to 6) and root=/dev/ram without rootfstype
The rd_size... |
I used the setenv command that ltib prints at the end of building images and the error vanished.
It seems that you should instruct system of size of your disk with that command.
setenv ramdisksize=90000,...
| kernel panic not syncing: vfs :unable to mount root fs on unknown block(31,1) |
1,548,861,490,000 |
From the answers to this question I have discovered that the embedded Linux distribution provided to me, by my hardware supplier, was not built with kernel support. If I am to use this distribution I have to be able to install drivers for some CANBUS hardware that will be attached. The source for the drivers is provid... |
By definition, if the kernel does not support loadable modules, you cannot load a module.
As you have already been told, there is something you can do: install a kernel compiled by someone else or recompile a kernel, with loadable modules and all the extra drivers you like.
I recommend that you first try installing an... | Installing a .ko module on an embedded Linux system that does not support modules |
1,548,861,490,000 |
I am just a newbie that is trying to learn. I can't see anything in the OLED display (ssd0303).
I am just using this demo: https://www.freertos.org/portlm3s811keil.html
as you can see it says that:
The print task is the only task permitted to access the LCD - thus
ensuring mutual exclusion and consistent access to ... |
I fixed by compiling via Keil instead of gcc:
https://forums.freertos.org/t/i-am-trying-to-emulate-a-board-which-has-a-oled-display-but-cant-see-anything-can-you-tell-me-if-there-is-something-important-i-am-not-considering/18689/3
| I am trying to emulate a board which has a OLED display, but can't see anything. Can you tell me if there is something important I am not considering? [closed] |
1,548,861,490,000 |
My Target Setup:
SOC: STM32H743 (Cortex m7 single core)
Internal Flash: 2MB
Board: Waveshare CoreH7XXI
On-board DRAM: 8MB, Start_Address: 0xd0000000, Size_in_bytes: 0x7A1200
SDCARD: 1GB
Bootloader: mainline u-boot (only I've modified the device tree and added my board files, almost everything is default)
kernel: ... |
You aren't passing any bootargs to the kernel, and since you're bypassing the logic to have a regular Linux distribution provide that for you, you need to pass in something that says where the console is, to Linux, so it will print out messages, as well as your root device.
| u-boot stuck at Starting Kernel |
1,421,080,145,000 |
Received my Jetson TK1 yesterday. After unboxing it and configuring the Linux GUI, rebooting the device with a mouse (cordless) attached to its USB 3.0 port takes it to some sort of Command line page where it probably loads some files and then the screen starts printing " [ . ] ". Nothing happens beyond that until I r... |
You should make sure you are not using serial console. Please check your /boot/extlinux/extlinux.conf and the "console=" line. If you have such a line, please remove it. It's blocking the HDMI output according to our testing.
| Jetson TK1 boot issues |
1,421,080,145,000 |
I've been trying to get gps data from an embedded system. This is the command I use:
gpscat /dev/ttyS2
And I get a continuous stream of output like this:
$GLGSV,1,1,03,70,14,098.6102,E,121853.000,A,A*50
$GPRMC,121853.000,A,59480,N,00604.6102,E,AA,10,1.0,203.6,47.6,,*64
$04.6102,E,121854.000,A,A*57
$GPRMC,1218... |
read about NMEA protocol its raw of them, details here, and here.
each line is frame of protocol:
$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A
Where:
RMC Recommended Minimum sentence C
123519 Fix taken at 12:35:19 UTC
A Status A=active or V=Void.
4807.038,N Lati... | How do I interpret the results of gpscat? [closed] |
1,350,499,117,000 |
In Linux I can create a SHA1 password hash using sha1pass mypassword. Is there a similar command line tool which lets me create sha512 hashes? Same question for Bcrypt and PBKDF2.
|
Yes, you're looking for mkpasswd, which (at least on Debian) is part of the whois package. Don't ask why...
anthony@Zia:~$ mkpasswd -m help
Available methods:
des standard 56 bit DES-based crypt(3)
md5 MD5
sha-256 SHA-256
sha-512 SHA-512
Unfortunately, my version at least doesn't do bcrypt. If your C library ... | How to create SHA512 password hashes on command line |
1,350,499,117,000 |
When I installed Ubuntu 10.04 and, now, 10.10, I was offered the option of enabling "encrypted LVM" for my hard drive.
After choosing that option, I am prompted for my password during boot to decrypt the LVM.
Now, I am thinking about setting up a headless server that runs Linux (not necessarily Ubuntu), but I am worri... |
For newer versions of Ubuntu, for example, 14.04, I found a combination of @dragly and these blogposts' answers very helpful. To paraphrase:
(On server) Install Dropbear
sudo apt-get install dropbear
(On server) Copy and assign permissions for root public/private key login
sudo cp /etc/initramfs-tools/root/.ssh/id_... | SSH to decrypt encrypted LVM during headless server boot? |
1,350,499,117,000 |
Security team of my organization told us to disable weak ciphers due to they issue weak keys.
arcfour
arcfour128
arcfour256
But I tried looking for these ciphers in ssh_config and sshd_config file but found them commented.
grep arcfour *
ssh_config:# Ciphers aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfou... |
If you have no explicit list of ciphers set in ssh_config using the Ciphers keyword, then the default value, according to man 5 ssh_config (client-side) and man 5 sshd_config (server-side), is:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,
[email protected],[email protected],
... | SSH: How to disable weak ciphers? |
1,350,499,117,000 |
I need to password protect my PDF file(s), because I am going to send them through email and I want anyone who would view my PDF file(s) to be prompted for a password.
How can I add a password to a PDF in Linux Mint 17.1?
|
You can use the program pdftk to set both the owner and/or user password
pdftk input.pdf output output.pdf owner_pw xyz user_pw abc
where owner_pw and user_pw are the commands to add the passwords xyz and abc respectively (you can also specify one or the other but the user_pw is necessary in order to prohibit opening... | How to set password for pdf files? |
1,350,499,117,000 |
Using command line, I know that I can encrypt a directory with the following command:
zip -er Directory.zip /path/to/directory
However, this does not encrypt the filenames themselves. If someone runs:
unzip Directory.zip
and repeatedly enters a wrong password, the unzip command will loop through all of the contained... |
In a zip file, only file contents is encrypted. File metadata, including file names, is not encrypted. That's a limitation of the file format: each entry is compressed separately, and if encrypted, encrypted separately.
You can use 7-zip instead. It supports metadata encryption (-mhe=on with the Linux command line imp... | How to zip directory with encryption for file names? |
1,350,499,117,000 |
I have Alice's public key. I want to send Alice an RSA encrypted message.
How can I do it using the openssl command?
The message is:
Hi Alice! Please bring malacpörkölt for dinner!
|
In the openssl manual (openssl man page), search for RSA, and you'll see that the command for RSA encryption is rsautl. Then read the rsautl man page to see its syntax.
echo 'Hi Alice! Please bring malacpörkölt for dinner!' |
openssl rsautl -encrypt -pubin -inkey alice.pub >message.encrypted
The default padding schem... | How to encrypt messages/text with RSA & OpenSSL? |
1,350,499,117,000 |
I try to find a script to decrypt (unhash) the ssh hostnames in the known_hosts file by passing a list of the hostnamses.
So, to do exactly the reverse of:
ssh-keygen -H -f known_hosts
Or also, to do the same as this if the ssh config HashKnownHosts is set to No:
ssh-keygen -R know-host.com -f known_hosts
ssh-keyscan... |
Lines in the known_hosts file are not encrypted, they are hashed. You can't decrypt them, because they're not encrypted. You can't “unhash” them, because that what a hash is all about — given the hash, it's impossible¹ to discover the original string. The only way to “unhash” is to guess the original string and verify... | How to decrypt hostnames of a crypted .ssh/known_hosts with a list of the hostnames? |
1,350,499,117,000 |
Today I got this warning issued by OpenSSL in Cygwin after updating some packages, I believe openssl was included:
*** WARNING : deprecated key derivation used.
Using -iter or -pbkdf2 would be better.
The OpenSSL version used in Cygwin was:
OpenSSL 1.1.1b 26 Feb 2019
This happened while decrypting my Backup on B... |
Comparing the Synopsys of the two main and recent versions of OpenSSL, let me quote the man pages.
OpenSSL 1.1.0
openssl enc -ciphername [-help] [-ciphers] [-in filename] [-out filename] [-pass arg] [-e] [-d] [-a/-base64] [-A] [-k password] [-kfile filename] [-K key] [-iv IV] [-S salt] [-salt] [-nosalt] [-z] [-md dig... | OpenSSL 1.1.1b warning: Using -iter or -pbkdf2 would be better while decrypting a file encrypted using OpenSSL 1.1.0g |
1,350,499,117,000 |
I tried removing LUKS encryption on my home directory using the following command:
cryptsetup luksRemoveKey /dev/mapper/luks-3fd5-235-26-2625-2456f-4353fgdgd
But it gives me an error saying:
Device /dev/mapper/luks-3fd5-235-26-2625-2456f-4353fgdgd is not a
valid LUKS device.
Puzzled, I tried the following:
crypts... |
ANSWER FROM 2013 - See other answers for happy times
Backup
Reformat
Restore
cryptsetup luksRemoveKey would only remove an encryption key if you had more than one. The encryption would still be there.
The Fedora Installation_Guide Section C.5.3 explains how luksRemoveKey works.
That it's "impossible" to remove the e... | How to remove LUKS encryption? |
1,350,499,117,000 |
I would like to password protect or encrypt a directory and all the files within it (for the whole directory tree below it). I do not want to bother the whole home directory, I want a specific directory with some files and folders in it. I would like to be able to encrypt the directory or decrypt it using a password. ... |
Use encfs (available as a package on most distributions). To set up:
mkdir ~/.encrypted ~/encrypted
encfs ~/.encrypted ~/encrypted
# enter a passphrase
mv existing-directory ~/encrypted
The initial call to encfs sets up an encrypted filesystem. After that point, every file that you write under ~/encrypted is not stor... | Simplest way to password protect a directory and its contents without having to create new files? |
1,350,499,117,000 |
How can I verify if a hard drive is encrypted in Fedora 20?
If not, does it mean I have to re install Fedora to encrypt it?
|
Assuming that the drive is /dev/sdb, and the partition you want to check is /dev/sdb1, run this command:
$ blkid /dev/sdb1
the output will change if the partition is encrypted or not:
/dev/sdb1: UUID="xxxxxxxxxxxx" TYPE="crypto_LUKS" #encrypted
/dev/sdb1: UUID="xxxxxxxxxxxx" TYPE="ext4" #not encrypted, fs ... | Verify if a hard drive is encrypted on Linux |
1,350,499,117,000 |
What's the fastest method to backup and restore a luks encrypted device (e.g. a full encrypted usb-device to a image-file).
The usb-device can be decrypted/accessed. I'm looking for a solution to mount the backup image as a file (encryped). Can it be possible?
Keep it simple, stupid.
|
cryptsetup handles image files just as well as block devices, if that was your question. So if you make a dd image (which will be freaking huge) it will work. And if it didn't, you could just create the loop device yourself.
Best practice (if you want to keep the backup encrypted) is to encrypt the backup disk also, t... | Best practice to backup a LUKS encrypted device |
1,350,499,117,000 |
Are there any Linux boot loaders supporting full disk encryption (a la TrueCrypt). I know there was work towards adding encryption support to GRUB2, but this does not seem to be ready yet. Any other options?
(Note that I am really referring to full disk encryption here—including /boot)
Most of the answers describe a s... |
I think the current version of GRUB2 does not have support for loading and decrypting LUKS partitions by itself (it contains some ciphers but I think they are used only for its password support). I cannot check the experimental development branch, but there are some hints in the GRUB page that some work is planned to ... | Linux boot loaders supporting full disk encryption? |
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