I would like to have fbtft showing boot splash screen at startup and then, when the boot is finished, start a program which directly talks to the display via /dev/spidev0.0
When I enable fbtft (modprobe fbtft_device and modprobe flexfb), the device /dev/spidev0.0 disappears, so the user program cannot talk to the display. How can I disable fbtft and reenable spidev at runtime? I tried
modprobe -r flexfb
modprobe -r spidev
modprobe -r spi_bcm2835
modprobe spidev
modprobe spi_bcm2835
Without success. There are no errors and fbtft seems to be disabled (no mention in lsmod) but there is still no /dev/spidev0.0, only /dev/spidev0.1
What I am missing?
Thanks a lot!
According to the developer of fbtft, the module fbtft_device does not restore the spidev device when unloaded. In order to restore it at runtime, one could create a Device Tree overlay that adds a spidev device and load it using the dtoverlay command.
As I have no experience in device tree, I followed an other idea of the fbftft developer (thanks for the hint): I made a initramfs with my own splashscreen program (using spidev), avoiding fbtft altogether.
See fbftft issue 548
Related
I have properly installed and setup WSL2. It works fine.
I also setup X11 forwarding and X server (VcXsrv). I can launch GUI apps such like konsole or gvim or even google-chrome from a bash shell.
Now I want to launch konsole by simply double clicking a short cut on the desktop without launching the bash command mode terminal. How should I do it?
I tried running this in cmd:
> wsl /usr/bin/konsole
and it reports:
qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb.
I'm guessing it is because some X11 forwarding configurations were not properly setup, so I created a k.sh as follows:
#!/usr/bin/bash
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2; exit;}'):0.0
export LIBGL_ALWAYS_INDIRECT=1
/usr/bin/konsole &
The first two lines were the X11 settings in my .bashrc, the last line launches konsole.
It works fine under bash environment; but when I ran
wsl k.sh
from windows cmd environment, it silently quitted without launching the konsole.
I'm out of ideas. What should I do to directly launch konsole or other Linux GUI apps under windows without having to getting into bash?
Thanks in advance.
You are asking about two different command-lines, and while the failures in running them via the wsl command have the same root-cause, the underlying failures are likely slightly different.
In both cases, the wsl <command> invocation results in a non-login, non-interactive shell where the command simply "runs and exits".
Since the shell is non-login/non-interactive, your startup files (such as ~/.bashrc and ~/.bash_profile, among others) are not being processed.
When you run:
wsl /usr/bin/konsole
... the DISPLAY variable is not set, since, as you said, you normally set it in your ~/.bashrc.
Try using:
wsl -e bash -lic "/usr/bin/konsole"
That will force bash to run as a login (-l), interactive (-i) shell. The DISPLAY should be set correctly, and it should run konsole.
Note that the quotes probably aren't necessary in this case, but are useful for delineating the commands you are passing to bash. More complicated command-lines can be passed in via the quotes.
As for:
wsl k.sh
That's likely a similar problem. You are doing the right thing by setting DISPLAY in your script, but I notice that you aren't using a fully-qualified path it. This would normally work, of course, if your script is in a directory on the $PATH.
But I'm guessing that you might add that directory to the $PATH in your startup config, which means (again) that it isn't being set in this non-login, non-interactive shell.
As before, try:
wsl -e bash -lic "k.sh"`
You could also use a fully-qualified path, of course.
And, I'm fairly sure you are going to run into an issue with trying to put konsole in the background via the script. When WSL exits, and the bash shell process ends, the child konsole process will terminate as well.
You could get around this with a nohup in the script, but then you also need to redirect the stderr. It's probably easiest just to move the & from the script itself to the command-line. Change your k.sh to:
#!/usr/bin/bash
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2; exit;}'):0.0
export LIBGL_ALWAYS_INDIRECT=1
/usr/bin/konsole
Then run it with:
wsl -e bash -lic "k.sh &"`
Finally, a side note that when and if you can upgrade to Windows 11, it will automatically create Windows Start Menu entries for any Linux GUI app you install that creates a .desktop file. You can manually create .desktop files to have WSL create Start menu items for most applications.
For reference, in Windows 11 it's easier. To run a GUI application without a terminal window popping up, you just need to call wslg.exe instead of wsl.exe.
So, for example:
target: C:\Windows\System32\wslg.exe konsole
start in: C:\WINDOWS\system32
shortcut key: None
comment: Konsole
This tutorial shows how to install VcXsrv and and edit .bashrc to ensure that the "DISPLAY env var is updated on every restart".
DISPLAY env var needs to be dynamic setting.
I've used it successfully with WSL2 on Windows10 Version 21H2 (OS build 19044.2130) to run Chrome, Edge, and thunar. I'm using the Ubuntu 20.04 Linux distro.
To edit .bashrc follow these instructions.
I recently saw that ChromeOS added the functionality to do split screen windows in tablet mode in the most recent dev releases. So I put my Chromebook R11 in dev mode for the first time and updated to version 62.
The flag is one of the many on this list https://peter.sh/experiments/chromium-command-line-switches/
The only resources for actually executing these switches was http://www.chromium.org/for-testers/command-line-flags
So I tried following the steps. I went to the crosh shell with Ctrl-Alt-T. Then I typed "shell". Then "sudo su". Then I tried to modify with "sudo vim /etc/chrome_dev.conf", but it was readonly so it didn't save.
So I visited here www dot chromium dot org/chromium-os/poking-around-your-chrome-os-device and followed the steps to making changes to the filesystem and disabling rootfs verification. But the command it told me to enter just gave me an error: "make_dev_ssd.sh: ERROR: IMAGE /dev/mmcblk0 IS NOT MODIFIED."
I'm running out of ideas and resources here..
make_dev_ssd.sh is how you disable rootfs verification and modify files in the rootfs. If that's not working, that might be a bug in that script that should be reported & fixed upstream (e.g. https://crbug.com/new).
That said, are you sure you need to pass a command line flag ? Look at chrome://flags and see if the feature you want to access is available there. Many command line flag is also available on that page.
Try this:
sudo su
cp /etc/chrome_dev.conf /usr/local/
mount --bind /usr/local/chrome_dev.conf /etc/chrome_dev.conf
echo "--arc-availability=officially-supported " >> /etc/chrome_dev.conf
I am struggling to disable USB ports on macs with the new Yosemite
My original intention was to give read only access to USB drives but it seems impossible, so I decided to go for the complete removal of the USB access
I followed the instructions on the osX manual but won't work
I tried this, posted here in the forum: link but it won't work
What I get now is this error link
(kernel) Can't remove kext com.apple.iokit.IOUSBMassStorageClass; services failed to terminate - 0xdc008018.
Failed to unload com.apple.iokit.IOUSBMassStorageClass - (libkern/kext) kext is in use or retained (cannot unload).
It may be because I removed the file from the extensions folder first, but if that was the case, why usb is still working?
Hope you can help somehow.
Cheers
Unload it first with
kextunload /System/Library/Extensions/IOUSBMassStorageClass.kext/
However having said that removing and even deleting this kext in Yosemite doesn't seem to prevent USB working again on reboot. In fact you now lose the ability to unload the kernel extension once loaded.
I'd like to improve the previous answer but I cannot comment on it, so I will add it here.
I am having the same problem and to solve it I confirm that you should unload the driver with
kextunload /System/Library/Extensions/IOUSBMassStorageClass.kext/
In order to keep this setting at reboot, I added a call to the root crontab (since this won't be modified by updates nor other users)
to become root
sudo su -
modify root crontab
crontab -e
add the line to the file and close it
#reboot kextunload /System/Library/Extensions/IOUSBMassStorageClass.kext/
I hope this helps
You need to unload the AppleUSBCardReader and AppleUSBODD drivers as they load IOUSBMassStorageClass. Run the following commands in the terminal:
sudo kextunload -b com.apple.driver.AppleUSBCardReader <br>
sudo kextunload -b com.apple.driver.AppleUSBODD <br>
sudo kextunload -b com.apple.iokit.IOUSBMassStorageClass
Can anybody please guide procedure to setup tool-chain for MSP430 in Linux (particularly Ubuntu) ? I am using MSP430 launchpad (MSP-EXP430G2), and I need to setup compiler/build tools and debugger drivers.
If you install Texas Instruments' CCS IDE, Linux version, it will install the tool-chain. There are, however, other problems in developing for MSP430 in Linux. The bugs and fixes are detailed in my post here:
MSP430 / eZ430-RF2500 Linux support Guide
"Compile code using Code Composer Studio (CCS)
Download CCS for Linux.
Create a new CCS project with a Custom MSP430 Device or any other.
Compile the code. The result binary image will be in the workspace. The workspace path can be found in “File” / “Switch workspace”.
The file that should be programmed to the device is the project-name.out file.
Program and run device using mspdebug
Download and Install mspdebug
From the directory with the file project-name.out run:
$ sudo mspdebug rf2500
Now you are in mspdebug’s command line shell. Run the following to program and run the device:
(mspdebug) prog project-name.out
(mspdebug) run
Use Ctrl+c to pause run and get command line back.
Fix a Linux Kernel bug that prevents Minicom to communicate with device
The device path in /dev is /dev/ttyACM0. Currently, connecting to it
serially using utilities such as minicom is not possible, and you get the message “/dev/ttyACM0: No such file or directory”.
The bug is in Kernel module “cdc_acm”. The solution is to fix the bug in the source code, recompile the module and plug it instead of the existing one.
Find out Linux version:
$ uname -r
cdc_acm’s source is the files cdc-acm.c and cdc-acm.h. They are under the Linux path drivers/usb/class/.
Download these two files from a repository that matches your Linux version. Such repos are available in lxr.free-electrons.com and www.kernel.org.
Create a new directory and move the files to it.There are two code segments need to be removed or commented out:
The next lines appear in function “acm_port_activate()” on newer versions and in “acm_tty_open()” in older ones:
// if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
// (acm->ctrl_caps & USB_CDC_CAP_LINE))
// goto bail_out;
The next line appears in function “acm_port_shutdown()” on newer versions “acm_port_down()” in older ones:
// acm_set_control(acm, acm->ctrlout = 0);
Create a Makefile and compile:
$ echo 'obj-m += cdc-acm.o' > Makefile
$ make -C /lib/modules/`uname -r`/build M=$PWD modules
You should have a new cdc-acm.ko file in the directory
Replace the existing module (This change will be discarded after boot):
$ sudo rmmod cdc-acm
$ sudo insmod ./cdc-acm.ko
Communicate via the serial port using Minicom
Launch minicom setup from command line:
$ minicom -s
In the menu, choose:
Serial port setup
Press ‘A’ (for “Serial Device”).
Replace Current device path with:
/dev/ttyACM0
Press ‘E’ (for “Bps/Par/Bits”).
Set the correct data rate for your device.To lower the rate (to 1200, for instance), keep pressing ‘B’ (for “previous”) until the top line shows:
Current: 1200 8N1
Press “Enter” until returning to main menu, there, press “Exit”.This will exit the setup menu and start running on the device. From now on you should see messages over the serial connection: It is up to you to program the device with such messages."
Download the pre-compile tool-chain (.run file) form http://www.ti.com/tool/msp430-gcc-opensource
Unzip
Execute chmod +x <downloaded file>
Run the installer
enjoy!
I'm trying to build a Webkit Kiosk on a Raspberry Pi.
I found a good start at: https://github.com/pschultz/kiosk-browser
The things I want to do:
1) Start the kiosk without logging in (with inittab?)
Peter Schultz pointed out adding the following line:
1:2345:respawn:/usr/bin/startx -e /usr/bin/browser http://10.0.0.5/zfs/monitor tty1 /dev/tty1 2>&1
But he did not explain the steps to make this work (for noobs).
What I did is add his code to a personal git repository and cloned this repo to /usr/bin/kiosk and sudo apt-get install libwebkit-dev and sudo make.
The line to add to inittab will be:
1:2345:respawn:/usr/bin/startx -e /usr/bin/kiosk/browser http://my-kiosk-domain.com tty1 /dev/tty1 2>&1
If I do this, I generate a loop or some kind...
If you want to automatically load a browser full screen in kiosk mode every time you turn on the rpi you can add one of these two lines to the file /etc/xdg/lxsession/LXDE/autostart
#chromium --kiosk --incognito www.google.it
#midori -i 120 -e Fullscreen -a www.google.it -p
The first is for chromium and the latter is for midori, the rpi default lightweight browser.
Hint : Since we will use the rpi as a kiosk we want to prevent the screen from going black and disable the screensaver. Edit the autostart file:
sudo pico /etc/xdg/lxsession/LXDE/autostart
find the following line and comment it using a # (it should be located at the bottom)
##xscreensaver -no-splash
and append the following lines
#xset s off
#xset -dpms
#xset s noblank
Save, reboot.
More info on
http://pikiosk.tumblr.com/post/38721623944/setup-raspberry-ssh-overclock-sta
The upvoted answer suggest to run LXDE for it. You could also do it without such a heaver desktop enviorment. You could just start midori or chromium in an X session:
xinit /usr/bin/midori -e Fullscreen -a http://www.examples.com/
xinit chromium --kiosk http://www.examples.com/
Sometimes Fullscreen mode of midori is not working as expected and midori is not using whole screen. In these cases you could map it inside a very simple window manager like MatchBox to get real fullscreen. Due to xinit you have to wrap everything in a shell script.
#!/bin/sh
matchbox-window-manager &
midori -e Fullscreen -a http://dev.mobilitylab.org/TransitScreen/screen/index/11
Autostart could be done simply be using /etc/rc.local.
More information concerning screensaver issues and an automated restart could be found here: https://github.com/MobilityLab/TransitScreen/wiki/Raspberry-Pi#running-without-a-desktop
Chromium has a dependency problem on some debian derivate for arm architecture. For Cubian you find the bug report here. I am not sure if you could install chromium on latest Raspbian without problem.
But I really could recommend midori. It's very fast and support for modern web technologies is very good. As Chromium it is using webkit as rendering engine. If you miss some html5 / css3 features consider an update of libwebkitgtk (for example by using package of debian testing).
It's possible you haven't set the DISPLAY environment variable.
Try:
export DISPLAY=:0
/usr/bin/startx /usr/bin/browser
Or, browser can also take a display argument (so you don't need the environment variable):
/usr/bin/startx /usr/bin/browser :0
This works for me on Raspbian from a standard terminal shell (I'm logged in over SSH).
Updated for the current version of Raspbian (with Pixel desktop) install with noop 2.0.
I found you need to edit in two different places to get it to work.
/etc/xdg/lxsession/LXDE/autostart
/home/pi/.config/lxsession/LXDE-pi/autostart
So my configure file is:
# #xscreensaver -no-splash
#xset s off
#xset -dpms
#xset s noblank
#chromium-browser --kiosk --incognito http://localhost
And that's it.
You should probably start with checking if /usr/bin/kiosk/browser is working at all. You should start normal X session (graphical environment) on your RaspberryPi, launch terminal, try running this command:
/usr/bin/kiosk/browser http://my-kiosk-domain.com
and see what it prints on the terminal. Is this working? Do you see any error messages?
I'm trying to build a Webkit Kiosk on a Raspberry Pi.
I think Instant WebKiosk for Raspberry Pi could be useful for you.
See: http://www.binaryemotions.com/raspberry-digital-signage/