Raspberry Pi 3 OpenWrt - sd-card

I have a trouble build OpenWrt with SD card.
I download the source, git://github.openwrt.org/openwrt.git and run "make menuconfig", set target "brcm27xx", "brcm2710", "Raspberry Pi 3 Model B".
And finish the configuration, build success.
Using "sudo dd if=openwrt....img of=/dev/sdb bs=2M", I create SD card.
When I boot Raspberry Pi 3 with creating SD card, the Kernel message with error.
run "mount"
/dev/root/ type ext4 ro(read-only) file system.
What is the problem!! Because of this I can not do anything...
Please Help me...

I have been using dd for a while now and it is both very powerful and very unforgiving, in the sense that your console will suggest the writing of the image is concluded but in actuality it has not. My images constantly failed for much the same reason as yours so now use my alternative command line, see below....
sudo dd if=openwrt....img of=/dev/sdb bs=2M
Here is my suggestion
sudo dd if=openwrt....img of=/dev/sdb bs=4096 conv=sync,notrunc status=progress; sudo sync
the last command may be unnecessary as sync is defined within dd command line. remember all of the above is one a line command not two wrap is ok I hope this helps you

This question is almost a year old and people might come across this in the future.
To run OpenWRT/LEDE on Raspberry Pi, you need to flash an image on a microSD. You may download the images through this link(Just search for the particular RPi Model): https://openwrt.org/toh/views/toh_fwdownload
Then from personal experience, I use Etcher to flash the image on the microSD. You may download it through this link: https://etcher.io/
Hope this helps someone out there. :)

Related

how to clone raspbian OS with all files and settings

I am finishing a project in raspberry pi 1 b+, and I would like to clone your raspbian operating system, with all the configurations, installations and files, that you now have installed, in order to record this image in another memory, as a backup in case of that the memory that has rpi fails,
how could i do it? Thanks in advance
Here's one way:
Power off your Raspberry Pi.
Remove the SD card and put it in a PC running Linux or a Mac.
Use dd to read the entire SD card into a file (disk image) on that PC. This may take a few minutes, depending on the capacity/speed of your SD card and the speed of your PC.
The command will look something like:
sudo dd if=/dev/XXXXX bs=65536 > RaspberryPiImage.bin
where XXXXX is whatever is the furthest from a in the list sda, sdb, sdc through sdz.
Check the size of the file RaspberryPiImage.bin corresponds to the full capacity of your SD card. So if your SD card is 16GB, you should see close to 16GB if you run:
ls -lh RaspberryPiImage.bin
You'll probably want to compress the image as it will almost certainly be a) large and b) readily compressible.
You could use:
gzip RaspberryPiImage.bin

OS Development. Creating bootable iso from files.

I'm studying OS development and I use brokenthorn resource but with a little bit different tool, namely, I use CentOS, NASM and Qemu as a test/dev environment. I've been facing some issues while creating bootable img file with secondary loader.
I've got two files:
1. bootloader.bin which is first stage loader.
2. stage2.bin which is secondary loader.
In order to create bootable img file I do the following:
dd if=/dev/zero of=floppy.iso bs=1024 count=1440 -- Creating empty file
mkfs.vfat -F 12 floppy.iso --Creating file system in the file
dd if=../bin/bootloader.bin of=floppy.iso bs=512 count=1 conv=notrunc --Writing first loader to the boot sector
sudo mount -o loop floppy.iso /mnt/floppy/ -- Try to mount file system to write secondary loader using previously create FAT-12 files system.
In the last step I'm getting the following error:
mount: /dev/loop0 is write-protected, mounting read-only
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
Can you please help me to understand what I'm doing wrong and what other ways I can use to accomplish creating bootable img with file system on board.
Thanks!
I once stumbled upon the similar problem and this answer may be of help to you.
However I would strongly recommend you switching to bootloader like Grub and spend time and effort developing the actual OS of yours. For that I would reccomend grub resque as it's simple to use and allows to to quickly create ISO that you can either burn or feed to virtual machine. Otherwise, you may just drown in all these minor things like enabling protected mode, loading your stages and so on.

Bare metal Raspberry Pi 2: Generating an SD card image for QEMU emulation

I've recently been getting into bare metal development for the Raspberry Pi 2, and having some success. Admittedly I've hesitated to buy an actual physical device until I feel I can do something useful with it, for the time being I've been emulating the device using qemu 2.11.0.
So far I've developed multicore capabilities for my kernel, as well as simple Serial I/O, but I feel I'd like to get much further before working with a physical device.
My issue right now is that I'm trying to learn how to place my kernel onto an SD card image and boot qemu-system-arm from that SD card image, so I can properly emulate a kernel loaded from the raspberry pi 2 bootloader.
I've gotten as far as grabbing the SD card contents from https://github.com/raspberrypi/firmware ... aster/boot, and using the following script to create the image and load my kernel into it. I've seen that people have figured out how to load Raspbian from an emulated SD card, so I figure I can do the same.
#!/bin/bash
OUTPUT_IMG=os.img
OUTPUT_IMG_SIZE=40
TEMP_MOUNT_DIR="$(mktemp -d)"
# the SD card boot partition contents are in this folder...
OUTPUT_IMG_CONTENTS_DIR="./sd"
OS_DIR="${HOME}/os"
OS_BINARY="${OS_DIR}/kernel.bin"
dd if=/dev/null of=${OUTPUT_IMG} bs=1M seek=${OUTPUT_IMG_SIZE}
mkfs.fat -F 32 ${OUTPUT_IMG}
sudo mount -t vfat -o loop ${OUTPUT_IMG} ${TEMP_MOUNT_DIR}
make -C ${OS_DIR} clean
make -C ${OS_DIR}
sudo cp -r ${OUTPUT_IMG_CONTENTS_DIR} ${TEMP_MOUNT_DIR}
sudo cp ${OS_BINARY} "${TEMP_MOUNT_DIR}/kernel.img"
The only issue is that qemu doesn't seem to boot from this image using the following command:
qemu-system-arm -machine raspi2 -serial file:serial.log -sd ./dev/os.img
I've tried a few different combinations, but to no avail.
I can see from hooking GDB that the kernel is simply not booting from this card image. Loading the kernel directly into qemu with the -kernel argument works otherwise perfectly.
I was wondering if anyone here had any insight on how to accomplish this!
Any help here would be greatly appreciated!
Your command won't work because you haven't passed QEMU either a guest BIOS or a guest kernel to run. The QEMU arm boards aren't like the x86 PC machine, which always automatically runs a guest BIOS image. If you want to run a BIOS (probably UEFI?) you need to find a suitable BIOS blob and pass it to QEMU with the -bios argument. Then QEMU will run the BIOS code, which will hopefully include SD card drivers to load the kernel and so on off the SD card.
Just using -kernel is much simpler...
After doing a bit of reading and searching online, as well as a bit of help from other contributors such as Peter Maydell with his answer above, I think I've answered my own question. Unless I'm mistaken qemu-system-arm does not fully emulate the Raspberry Pi boot process, and instead just loads the kernel specified with the -kernel argument by loading the binary into the guest system's memory and jumping to the entry point. It doesn't look like any additional hardware bootloading is emualted for -M raspi2 unfortunately.
Can ARM qemu system emulator boot from card image without kernel param?
This question is similar and contains some more useful details on this issue, relating to qemu-system-arm as a whole..

RPi2 UART Setup & Operation Issues

I'm currently busy with my masters project which involves setting up comms on UART between a Raspberry Pi Model 2 B V1.1 and a Pixhawk Flight Controller using Mavlink protocol.
The first step is, of course, to get the UART set up and working. I'm not one to run after help at the first sign of a problem. I have been struggling with this for days and it's forced me to doubt the purpose of my existence more than once. I feel stupid and frustrated. Please see if you can provide any assistance.
My first resource was this tutorial, which should be relatively straight forward:
http://ardupilot.org/dev/docs/raspberry-pi-via-mavlink.html
The tutorial simply installs all the necessary packages and dependencies, as well as sets up the UART. I followed the steps to disable OS use of the serial port through raspi-config, however after attempting to test the connection I get an error:
[Errno 2] No such file or directory: '/dev/ttyAMA0'
Which is very strange. So after disabling and enabling OS use of serial port through rasp-config a few times and checking, every time I disable it, the /dev/ttyAMA0 file disappears. Now how the hell is anything supposed to work on the UART if disabling OS use of the UART removes that file!? Nevertheless I powered through. I enabled OS use of the serial port, which leaves the ttyAMA0 file right where it is and followed another suggestion, which is to change the /boot/cmdline.txt and remove all reference to ttyAMA0, as shown in the following link:
http://www.raspberry-projects.com/pi/pi-operating-systems/raspbian/io-pins-raspbian/uart-pins
This seemed to work alright. I could now initiate comms between the RPi and the Pixhawk flight controller and get some information that looked correct. Then the black magic started. The next day I tested the connection and it consistently spat out complete rubbish. But Nothing changed since the previous day. Somewhere I must be missing something. I followed all the same tutorials and steps attempting to get the more positive results I got the previous day. However that only led to more erratic behaviour. When connecting the serial lines to my Pixhawk Flight Controller, the keyboard/mouse seems to get interrupted momentarily every now and then. Everything just went backwards. I have already reinstalled Raspbian Jessie in a desperate attempt to get things to work.
Here are a few things I suspect could possibly contribute to the problems:
Baud rate not correct (to communicate with my Flight Controller baud rate needs to be 57600). Best way I've found to set this baud rate is to append "init_uart_baud=57600" to /boot/config.txt/. I have also read about other ways such as appending a line to /etc/crontab. Any suggestions?
Pixhawk miraculously and sporadically refused to communicate back with RPi.
Any assistance will be appreciated. Thank you.
SOLVED:
Looks like a known bug in the latest raspbian, easy to fix though.
These need to be done as the root user.
Disable "serial console" through GUI-preferences or "sudo raspi-config." Then reboot the pi.
Then change the following line in the file /boot/config.txt at the bottom of the file from:
enable_uart=0
to
enable_uart=1
Disable the ModemMonitor service by running the following command as root:
systemctl disable ModemManager.service
Then add youself to the dialout group, just to be sure you have the required permissions on the serial port:
adduser pi dialout
That should give you unrestricted proper access to the serial port.
Resources:
[url]https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=148515[/url]
and
[url]https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=82779[/url]
I had researched this for days now and troubleshooting all the readings listed on Google sites. I solved the serial UART settings for connecting my RPi3 Model B (typed at command line the following:
`cat /proc/cpuinfo`
to find my Pixhawk hardware info.)
FYI: You must be root when working with mavproxy so, sudo su
or sudo -s
Also, you must be a member of the dialout group, so do this at CMD line:
sudo usermod -a -G dialout root (enable root user!)
Do all the RPi regular stuff:
sudo apt-get update && sudo apt-get upgrade and sudo rpi-update.
Did all as outlined in the Ardupilot website. I did NOT use the
"apsync-rpi". (I used the 2017-03-02-raspbian-jessie.img.) at here
On my RPi3, using $uname -a: results--> Linux raspberrypi 4.4.50-v7+
My $sudo nano /boot/config.txt file has one change at bottom of file;
THIS statement: enable_uart=1 (has a good side effect of forcing the
core_freq to 250 which reduces poor signal frequency)
Important discovery: so the articles state that RPI3 UART and tty settings have changes. (link here)
What I have discovered after much ado is this for my sudo nano /boot/cmdline.txt file:
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 etc.,.
-Notice I am not using ttyS0 in the /boot/cmdline.txt file. I tried the ttyS0 a dozen times and it never worked properly. For some reason, I am not able to explain it at this time, although the console=/dev/tty1 works if written in the /boot/cmdline.txt file.
Make sure you have the wiring correct between your RPi and the Pixhawk.
Telem 2. Also set the correct parameters in Mission Planner as I
have;
Go to CONFIGTUNING->STANDARD PARAMS; (my settings)
-The Serial0 baud rate(SERIALO_PROTOCOL) is: 115200
-The Console protocol selection(SERIAL0_PROTOCOL) is: MAVlink1
-Telem1 baud rate(SERIAL1_BAUD) is at: 115200
-Telem1 protocol selection(SERIAL1_PROTOCOL) IS MAVlink2
-Telemtry 2 Baud rate(SERIAL2_BAUD) is 921600
-Telemetry 2 protocol selection(SERIAL2_PROTOCOL) is MAVlink1
The RPi and pixhawk communicate at 921600 baud rate.
-Once I get the RPi3 powered up with it's own +5/VCC source and connect to my MP with a 3.0 USB cable from my PC-Windows10PRo, (okay, I have Arch and Debian Linux distros and Apple OSes too!) I enter:
`mavproxy.py --master=/dev/ttyS0 --baudrate 921600 --aircraft Plane`
It works for me!
Happy experimenting and flying!

Using MPI with two RaspberryPi

I am trying to make a 'dual core' RaspberryPi for a project I am working on. I had followed this tutorial by Simon Cox. Unfortunately I could not get the two RasPi to talk to each other. (This was using Hydra as the process manager)
After looking more carefully at the MPICH installers guide, which can be found here, I tried to use the -phrase to pass the passphrase I had created. However I could not find it as part of the hydra commands. So I re-installed with smpd and after many compiling attempts. I configured with:
/configure -prefix=/home/pi/mpich-install --with-pm=smpd --with-pmi=smpd
I also had to install libbsl-dev to get the MD5 that smpd requires. I also exported the path that the commands mpiexec and mpicc are in. After setting the passphrase I copied the image to a second SD card and put it in a second RasPi. I then set up the passphrase using ssh-keygen.
I was able to run the cpi program on the master Pi and the slave Pi individually but when I tried to run multiple processes on both at the same time I got the error
Fatal error in MPI_Init: Other MPI error, error stack:
MPIR_Init``_thread(392).................:
MPID_Init(139)........................: channel initialization failed
MPIDI_CH3_Init(38)....................:
MPID_nem_init(196)....................:
MPIDI_CH3I_Seg_commit(366)............:
MPIU_SHMW_Hnd_deserialize(324)........:
MPIU_SHMW_Seg_open(863)...............:
MPIU_SHMW_Seg_create_attach_templ(637): open failed - No such file or directory
Can someone please suggest how I can either fix this problem or get the RaspberryPis to communicate using MPICH?
Thanks
E.Lee
If anyone else has this problem make sure your hosts don't have the same name!
You can change it by following this tutorial http://raspi.tv/2012/how-to-change-the-name-of-your-raspberry-pi-new-hostname