I am developing a kiosk type application using Yocto and a raspberry pi3. I have an hdmi touchscreen attached and have a USB keyboard attached for development only. My problem starts when I try to start GTK in one of my processes.
My project involves creating the kernel, has several processes running for various tasks, and will have a touchscreen GUI based on GTK+3 (using Glade).
My kernel is working and my processes are running and able to communicate with each other. But, now I'm having problems getting any kind of graphical output on the screen. Right now, all I have is console access as root.
When I start my 'display-mgr' process it tries to start up GTK. When it tries to 'gtk_init()', I get:
Gtk-WARNING ++: ...timeinfo...: cannot open display:
I've tried the usual 'export DISPLAY' stuff, but it looks like I don't even have the Xserver installed on the board.
I have:
DEPENDS = "libconfig pkgconfig-native gtk+ gtk+3 glib-2.0 libxml2 gnome-common glade"
in the recipe for my process. I also have: DISTRO_FEATURES_append = " x11" in my image recipe. Is there some package that I've missed?
I would recommend you start with core-image-sato from poky distro, and gradually replace the pieces. Alternatively, use core-image-weston, which would use that instead of x11.
Related
buildroot make issue
I am relatively new to buildroot and linux in general.
I am trying to make an image for an atmel sama5. Basically after I configure the menu and the Linux kernel, I run the "make" command. During execution of make, the program cannot seem to download alsa-lib 1.1.7.tar.bz2. Make starts at this point until the data connection times out at which point it starts again. any ideas on how to resolve this?
Thanks
Is there a way or steps to follow to integrate a yocto SDK (standard or extensible) with VSCode? I want to cross-compile, remote connect, and debug a C/C++ application within VSCode for target hardware using a yocto generated Linux image. Is this possible? I know of the bitbake extension but couldn't find one for the SDK. Thank you!
Conservatively, I would say it depends on the level of integration you want to achieve but I use regularly VS Code to edit and build, sometime to debug C applications using a Yocto toolchain, that's really easy for Makefile projects for example.
Assuming you do not ask for Yocto integration into VS Code (I don't know if something exists) but really to use the tools generated by the SDK from Yocto and that you already are familiar with Yocto toolchain usage.
I personally compile on Linux server remotely from a Windows PC. The server contains therefore my projects and the Yocto toolchain.
I use for that the nice Remote SSH extension from Microsoft on VS Code. From there, I can edit easily the files, compile and a terminal is available (that's out of the scope of your question however).
So if working as me or directly in Linux, you can create a Makefile/CMake project for example. The C/C++ VS Code extension is a must have.
Each time you start working, you source the Yocto SDK toolchain and compile directly using make from the terminal window of VSCode. If you want to automatize the build step, you can use the task feature of VS which allows you to launch build script for example.
Regarding the remote connect, the terminal window of VS can also have multiple sub-windows with various connections like SSH to the target. The build script can also use scp to send the generated binary directly to the target but your question is vague regarding what you want to do.
Finally for the debug aspect, GDB is well supported in VS Code and the official doc is a good start as well as the C++ debugging doc.
On the Yocto side, you need to add gdbserver to the image running on the target, it can be done by adding the following to your conf/local.conf:
EXTRA_IMAGE_FEATURES += "tools-debug"
If you want to have debug information for the shared libs on the target, you also need to add:
EXTRA_IMAGE_FEATURES += "dbg-pkgs"
Finally, the SDK must be generated with the same options as the image running on the target and will contain the cross-gdb tool like -gdb to be used on the host side.
So that's possible but requires some setup especially the debug part. As far as I know, there is not a VS Code extension managing all these steps for you automagically.
im trying to make v4l2loopback work on my desktop PC (no hardware camera) with mint 19.3, kernel 5.4.0-42-generic x86_64.
I followed the official instructions and compiled from git the v4l2loopback module and everything seem to run correctly, as no error prompted while running the instructions, but when i do ll /dev/v* there's no /dev/videoN entry.
I also tried with the flags exclusive_caps=1 and devices=2 but to no avail.
Any idea what i might be missing or doing wrong?
you need to load the module (e.g. using modprobe) before you can use it.
see also https://github.com/umlaeute/v4l2loopback#run
I have a custom board with imx6dl chip and peripherals. I have compiled u-boot, zImage and rootfs from examples provided by manufacturer. But when i try to build yocto from git repo with latests releases, it fails to run (some drivers not working, board is loading and display interface, but touchscreen is not working for ex.),
Is there any way to include precompiled binaries zImage, u-boot and device table to bitbake recipes? I'm very new to yocto project, and only need to get bootable image with working drivers and qt5.
If you have a working boot chain (e.g. u-boot, kernel and device tree) that you have built out-of-yocto, then you might try building a rootfs only. This requires two main settings, to be made in your local.conf to get started. Please don't firget that this is just a starting point, and it is highly advised to get the kernel/bootloader build sorted out really soon.
PREFERRED_PROVIDER_virtual/kernel = "linux-dummy to have no kernel being built, and something like MACHINE="qemuarm" to set up an armv7 build on poky later than version 3.0. The core-image-minimal target should at least be enough to drop you in a shell for starters, and then you can proceed from there.
Additionally, it might be qorth asking the board vendor or the yocto community (#yocto on the freenode server) if they know about a proper BSP layer. FSL things are quite nicely supported these days, and if your board is closely related to one of the well-known ones, you've got a high chance that meta-freescale just does the trick nicely.
Addition:
#Martin pointed out the mention of Qemu is misleading. This is just the easiest way to make Yocto build a userland for the armv7-architecture which the imx6dl is based on. The resulting root filesystem should be sufficiently compatible to get started, before moving on to more tuned MACHINE configuration.
I installed CentOS 7.6 then installed all things QEMU on my machine. I have a SPARC image I need to bringing up in a VM. I've been using qemu-system-sparc.
$ qemu-system-sparc -m 256 -hda solaris_v2-qemu_v2.2.0.disk -nographic -bios ./openbios-sparc32
This is on a box on which I have Fedora-30 installed.
Can I use qemu-sparc to bring up my Solaris image: solaris_v2-qemu_v2.2.0.disk ?
If so, how?
BTW, qemu-sparc come with (on CentOS 7.6):
$ sudo yum install qemu*
PS> I've tried to install qemu-system-sparc on my CentOS box but ended up in a never-ending whack-a-mole game of dependencies.
After a great deal of web searches, I found this:
QEMU as an userspace emulator
QEMU usually comes in two flavors: qemu-system-* are system emulators
(able to run entire operating systems as seen in the previous
section), while qemu-* are userspace emulators (only able to run
userspace applications).
QEMU as an userspace emulator is thus able to directly execute a SPARC
application, by emulating the syscalls that the application requests.
Among the greatest features of this approach are:
The output of application is directly displayed in the terminal,
Arguments to applications are directly given through the command line,
QEMU returns the return code of applications, etc. QEMU really just
acts as a wrapper around the application, as time or nice do.
The only complicated thing you have to do in this approach is to
compile a cross-toolchain for SPARC, so SPARC programs can be compiled
on the host computer. Such a cross-toolchain can be generated by using
the fabulous crosstool-ng.
So the answer appears to be: no, you CANNOT use qemu-sparc to run your image in a VM.
You need the qemu-system-sparc, wich will "emulate" a sparc system.
qemu-sparc will only emulate the CPU and syscalls, thus a SPARC compiled program (that you can extract from your disk image if needed) will run on non-sparc hosts, while most syscalls be "translated" by qemu into your host syscalls, thus a SPARC program can run on said host. file io, kernel stuff, it mostly get translated and run on your host. Handy for debugging or reverse engineering.
Try:
yum install qemu-kvm
The dependencies are required ofcourse. Not very usefull in your case but you could also compile qemu yourself, maybe the dependencies overlap:
git glib2-devel libfdt-devel pixman-devel zlib-devel