I'm trying to get my raspberry pi zero power consumption to a minimum.
For this I want to disable the HDMI because I'm not going to use it, but can't find how.
I used buildroot to create my kernel, rootfs and dtb.
I tried disabling the HDMI in the kernel build but it is not possible, menuconfig forces me to have it set to Y.
I tried adding to the HDMI section in the dts "status = "disabled";". It was compiled successfully but no change in power consumption.
I thought maybe I can add something in boot/config.txt but couldn't find anything disabling HDMI from the rpi documentation here.
I know in a raspian OS there is a tvservice I can use to acheive this but my build doesn't have tvservice nor can I add it.
Does anyone know how I can disable the HDMI from the config.txt or any other way?
Thanks,
Robbie
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I've just gotten my Raspberry Pi Pico and am trying to get it ready to accept code. I've tried dragging and dropping MicroPython from the webpage and using Thonny to handle it automatically, but when I do either, it ejects itself and nothing has loaded. I'm trying to do this from a Pi 4. Any help would be greatly appreciated.
This is how I do it (but not on a RaspPI)... hold the BootSel button on the Pico and then plug it in. A new "disk" should appear to the OS (or on the desktop). Drag the Micropython UF2 file onto the new disk - this installs Micropython on the Pico. The file gets copied, the Pico saves it to flash, and the "disk" ejects itself.
Now, in Thonny, you have to select the correct board (Pico) and the correct serial interface device (/dev/it-depends-on-your-system). The Thonny page has notes for this. At this point, with Micropython, we talk to it over the serial line, not as a disk.
HTH.
I really does sound as if you are trying to install MicroPython without downloading it and/or to run a MicroPython program without installing the MicroPython system. You first have to install the MicroPython system, download a uf2 file, and only then can you install and run a MicroPython program using Thonny.
Answering here because I had trouble getting mine to work too. In my case, I somehow got my pico into such a state that Mass Storage Device mode would randomly disconnect / eject, often before I could even drag a new UF2 file to the device.
Since I didn't have the time to be successful with drag/drop before the device disconnected, I built and used picotool to push the "nuke memory" UF2 file (see link here). (BOOTSEL held down, plugin, hit enter on the terminal to run ASAP before the pico disconnects)
I actually had to do this two or three times, but after that it stopped being weird and Mass Storage mode works correctly again; I was able to install the MicroPython UF2 file with the normal drag and drop method and Thonny no longer disconnects.
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 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.
maybe someone of you can help me:
I have to make a custom linux build via buildroot. I have to use an attached LCD, which uses the ADS7846 driver, and I struggle to get it working. I included the resp. settings in config.txt, as provided by the LCD manufacturer, but dmesg would not reveal the hardware being recognized when booting the system.
When I do the same on a freshly installed Raspbian (that is, just include the required params in config.txt), I can verify that the driver loads successfully.
I made the kernel DT'able with mkknlimg and I can verify that it works - /proc/device-tree is present.
So what do I have to do to make this work? I'm lost...
any help greatly appreciated!
thanks a bunch,
Wolfgang
in the meanwhile, I found the solution. I needed to include udev support for the kernel to recognize the touch screen.
I have a hello world bootloader code in assembly written (I'm sure I coded it right). I have the .bin file with me and .exe also.
I want to test it now with a USB, how do I do it? Everything I googled out and found on the topic pretty much didn't work out.
I have tried the way with "Disk Explorer NTFS 3.66". I have also tried the mkbt way. Both of them though mentioned highly in blogs/forums/etc don't seem to work for some reason.
Disk Explorer is not letting me paste from file onto the bootsector.
Any ideas/help is much appreciated.
I am 99.9% sure that you won't be able to use bootloader with USB. Because, bootloader is initialized first then it loads the Operating System, which loads USB drivers. It can work if you can trick your machine to look for USB as a primary booting device (I was using a P4 with XP and couldn't get my system to do it). The thing that worked for me was a Floopy Drive, it was back in 2006 !
You can use a Virtual Machine as suggested by Federico, and emulate the USB drive as a booting device, that's the best option.
Follow the link given below . I think it will help you to make bootloader as "Hello World" in your usb .
http://pcguide4you.blogspot.in/2011/09/designing-simple-hello-world-bootloader.html