I have built the linux system for my RPi3 using buildroot. It boots properly and I can access the wired connection properly. However, I am stuck with enabling the wlan.
Here is what I have done so far.
Built the filesystem using buildroot:
make raspberrypi3_defconfig
make
After booting linux successfully I followed this link to enable wlan.
As the author of the post mentions, I had to select some of the wireless related packages by running make linux-menuconfig. But when I did run it, these packages were already selected.
I then ran make menuconfig and selected wpa_supplicant and other packages.
Now, when I boot the RPi3, wlan0 is not listed when I run ifconfig -a. I googled it a bit and found that there should be folder named wlan0 under /sys/class/net/. But I can only find eth0 and lo
Kindly guide me on how to get the wlan working. dmesg log is posted here
If you are using Buildroot, make sure you have selected BR2_PACKAGE_RPI_WIFI_FIRMWARE.
Also you have to manual load the wifi kernel module:
# modprobe brcmfmac
After that, you can confirm wlan0 with
# ifconfig -a
You could also configure Buildroot to build udev as /dev management option, in this case, WiFi kernel module will be loaded automatically.
Related
For various reasons, I'm trying to get a Soft-ROCE setup working. The plan is to move to RDMA-capable hardware, later, but for now Soft ROCE is a good choice to get started. I've started with some tutorials on Infiniband APIs, and they mostly make sense. However, I haven't been able to get even a single transaction working in a loopback device.
I created an rxe device using the following command:
# rdma link add rxe_lo type rxe netdev lo
It seems to come up fine, but none of the utilities I run seem to do anything (rping, ibv_rc_pingpong, etc.).
With my loopback device, rping fails like this:
# rping -c -v -a 127.0.0.1
rdma_resolve_route: No such device
If I create Soft ROCE devices on two separate computers, and then run that over the network, rping at least works:
# rdma link add rxe_eno1 type rxe netdev eno1
# # do the same on different computer...
# rping -s -v -a 0.0.0.0
# rping -c -v -a 192.x.y.z # on other computer
Is this a futile attempt, or is there a technical reason why local loopbacks won't work with Soft RDMA? I tried this on an Ubuntu and Fedora system, with the same results.
I'm new to raspberry pi's and Linux in general. I'm setting up some Pi's to access a webpage. I have tried using:
nano /home/pi/.config/lxsessions/LXDE-pi/autostart
then adding the line
#chromium-browser www.etc.com
but what I found is that while it auto starts chromium, it boots into openbox and the ethernet interface is disabled. I made sure to add
sudo nano /etc/network/interfaces and iface eth0 inet dhcp, but when I reboot again it changes nothing.
So my main question is how do I either make this same thing boot into the desktop AND open chromium, or have chromium startup auto AFTER boot up and log in.
I appreciate any insights and/or help with this.
You can run this alongside the GUI using the method below. I had the same issue and this was the only suggested method that worked.
sudo nano /etc/xdg/autostart/myapp.desktop
(Replace myapp with the desired file name)
Then add this to the file:
[Desktop Entry]
Exec=chromium-browser https://stackoverflow.com
Source : https://www.tomshardware.com/uk/how-to/run-script-at-boot-raspberry-pi
I'm using buildroot to compile a minimalistic linux with a 4.19-rt kernel. It is supposed to run on a raspberry pi 3b (arm processor). Additionally I want to run it on a x86_64 linux computer and found qemu as an emulation solution for that.
Building linux and kernel and running it on the raspi works. It boots, I can login and use it.
To test qemu I followed this instruction [1]. A recent raspbian with 4.19 kernel is booting fine so qemu seems to be installed correctly.
sudo qemu-system-arm -kernel ./qemu-rpi-kernel/kernel-qemu-4.19.50-buster -hda 2019-09-26-raspbian-buster-lite.img -cpu arm1176 -m 256 -M versatilepb -no-reboot -serial stdio -append "root=/dev/sda2 panic=1 rootfstype=ext4 rw" -dtb qemu-rpi-kernel/versatile-pb.dtb
Bringing 1. and 2. together fails. When I try to emulate any self build linux, qemu only shows a black screen and one CPU is using 100%.
I used the same sdcard.img that works on the real hardware. I also tried to recompile the whole system with a normal 4.19 kernel (without real time). And I tried to build a versatile system (make qemu_arm_versatile_defconfig && make). None of it works.
Command to start the emulation:
sudo qemu-system-arm -kernel zImage -drive format=raw,file=sdcard.img -cpu arm1176 -m 256 -M versatilepb -no-reboot -append "root=/dev/mmcblk0p2 panic=1 rootfstype=ext4 rw" -serial stdio
My main problem is, that there is absolutly no useful output. The command outputs the following
ALSA lib pulse.c:242:(pulse_connect) PulseAudio: Unable to connect: Connection refused
sdl: SDL_OpenAudio failed
sdl: Reason: ALSA: Couldn't open audio device: Connection refused
ALSA lib pulse.c:242:(pulse_connect) PulseAudio: Unable to connect: Connection refused
sdl: SDL_OpenAudio failed
sdl: Reason: ALSA: Couldn't open audio device: Connection refused
audio: Failed to create voice `lm4549.out'
and opens a window for the graphics output (that does not show anything). The message also appears when emulating raspbian so it does not seem to be the reason.
When I run qemu with the prebuild raspbian but without the -dtb argument, I get a message like "Error: invalid dtb and unrecognized/unsupported machine ID". I would at least expect something like this with my self build code. But because there is no output I'm out of ideas what even to google for.
Does someone maybe have an idea what I'm doing wrong or how I get qemu to provide me any useful information on what went wrong?
[1] https://blog.agchapman.com/using-qemu-to-emulate-a-raspberry-pi/
The problem is that a kernel will only boot on a piece of Arm hardware if it is compiled for that hardware. Otherwise it will generally fail, usually by crashing before it is able to output anything useful.
In particular, the QEMU 'versatilepb' machine is completely different to the Raspberry Pi. Any working set of instructions that use that machine type are really running a kernel built to work with the versatilepb board and a raspi userspace/filesystem on top of that. You're trying to build a kernel that has support for only the raspi on a machine that isn't a raspi, which won't work.
It is possible to build a kernel that works on more than one piece of Arm hardware, if you compile in the support for both board types (all the device drivers for both, etc). If you want to go down that path, I would suggest looking at the differences between the kernel config for the kernel that works and your one, and add plausible looking missing things until you find out what is actually required.
Your attempt to boot on QEMU directly from sdcard.img will not work, because QEMU's versatilepb board model does not support direct boot from sdcard (this would require us to run some kind of BIOS/firmware image in the guest, which we don't have). For versatilepb you need to supply directly to QEMU the kernel, possibly an initrd, and definitely the correct dtb for the versatilepb.
You might instead try looking at QEMU's "raspi2" and "raspi3" board models, which really do model the hardware of Raspberry Pis. The disadvantages however are that these models are missing some features and are not very actively developed, so often newer kernels don't boot on them, and also since there is no USB controller model there is no way to get networking. (This is why most blog posts etc suggest using the 'versatilepb' -- userspace doesn't often really care about exactly what hardware it's running on, so unless you're trying to do kernel development you can just run a versatilepb kernel and take advantage of the features like networking that that QEMU model has.)
Advanced Linux Sound Architecture (ALSA) tries to open audio interface device . you must provide audio device in qemu . Because the kernel is compiled with ALSA audio driver and you have compiled sdl library in Buildroot.
I've a wlan0 configured in my rasp pi (file /etc/network/interfaces and /etc/wpa_supplicant.conf)
In the past I could connect to it with no problems but now I can't. I've tried a few different LANs and I can't get any to work.
Everytime I do either ifdown or ifup I get the result:
Internet Systems Consortium DHCP Client 4.3.1
Copyright 2004-2014 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Can't allocate interface wllease {
interface .
Any hints?
A little late, but this happens when the dhcp lease file gets corrputed.
Try clearing the wlan0 leases with:
sudo echo "" > /var/lib/dhcp/dhclient.wlan0.leases
I think a better way would be just to remove the lease files using the following command.
rm -rf /var/lib/dhcp/*
I have a Pi that runs hostapd and dhcpd on arch linux to create it's own land with the Pi's (routers) IP being 10.0.0.1. This uses the wlan0 interface and it only serves as a standalone router running a web server.
Once I connect to the Pi, I use 10.0.0.1 to display the web pages, but I want to use a hostname such as firepi. I have tried using dnsmasq, but I haven't been successful. Any help would be greatly appreciated especially if you can give me some detailed examples as I am a novice.
The purpose of this system is that I have created a web app that you can use to ignite fireworks over WiFi at a safe distance. I would just like the convenience of using a hostname instead of the IP address.
I must add that I will more than likely be using an iPhone to connect to the server, should this affect anything.
Not too sure how or why but this is what I did and it is successfully working now, so this is just for future users who may need a similar setup to mine.
First I installed hostapd and dhcpd and made sure they were working. Next I changed '/etc/hostname' to firepi and the '/etc/hosts' and added '10.0.0.1 firepi'. Then I installed dnsmasq, and set the interface to wlan0, and finally added '10.0.0.1 firepi' to '/etc/resolv.conf'.
After a full reboot, I joined the network on my iPhone, navigated to firepi and sure enough, it worked!
Thanks to the other users for their advice and tips.
You can use avahi on Arch as well to resolve your hostname:
sudo pacman -S avahi nss-mdns
Start the avahi daemon:
sudo systemctl enable avahi-daemon.service
sudo systemctl start avahi-daemon.service
Edit /etc/nsswitch.conf
sudo vim /etc/nsswitch.conf
Change the line:
hosts: files myhostname dns
to
hosts: files myhostname mdns_minimal [NOTFOUND=return] dns
Reboot
Note: don't forget to add .local to your hostname.
See also:
http://blog.pixxis.be/post/77285636682/resolve-hostname-with-arch-linux-on-a-raspberry-pi
If you just want to be able to use "firepi" as hostname to connect to it, you can simply add it to your /etc/hosts file using the syntax "IP host".
To make it as easy as possible, run this command as root:
echo "10.0.0.1 firepi" >> /etc/hosts
That'll do the trick.
Can you try avahi ?
sudo apt-get install avahi-daemon and
sudo apt-get install avahi-browse
I've successfully used that on Raspian. Unless you change the hostname using
sudo raspi-config you will access via raspberrypi.local
Note that if you plan to access the RPi from Windows you will need to install Bonjour Service first(if you have iTunes intalled, you might have those, run services.msc and check if the Bonjour Service is started)
Another note: On a friend's iphone I've installed a generic vnc client and had x11vnc running on the RPi and succesfully managed to connect to the RPi (since avahi-daemon was installed)