crosscompiling for RPi on Windows host via NFS

I was interested in seeing my raspberry pi boot from NFS of a virtual Ubuntu machine on Windows to be able to cross compile, like proposed for OsX¹

To be able to enable this scenario for Windows I had to take some hurdles, as

• Ansible is not supported in Windows 10
• On my DHCP-hosted LAN the 192.168.* - IP - range is better equipped for connecting to the internet than 10.0.*.
• The /vagrant shared folder gives File I/O errors when hosted from windows

So this is how I did it:

First install VirtualBox and Vagrant on Windows, but don't install ansible as that's not supported in Windows.

Download this repository as zip and extract it to a directory, to retain the Unix-like linefeeds without carriage returns.

Edit the ´Vagrantfile²´ to suit your needs

From within that extracted directory start the Ubuntu-virtual machine with

vagrant up

This will boot a headless virtual-machine on your Windows PC which can be entered by ssh

vagrant ssh

If vagrant can't find ssh then follow the instructions that appear.

Within the ssh-session to the Ubuntu-image you can see the files in the Windows directory of your vagrantfile (in /vagrant):

ls /vagrant

• playbook.yml
• install_ansible.sh
• 2016-05-27-raspbian-jessie-lite.img

build a recent ansible-version, reply with a lower-case 'y':

cd 
. /vagrant/install_ansible.sh
cd /vagrant

edit the head of playbook.yml, to contain the local user and files to use, and the start of the root and boot-partitions as a result of sfdisk -d 2016-05-27-raspbian-jessie-lite.img, from which you take 512 * the start sector:

---
- hosts: localhost
  remote_user: vagrant
  vars:
    image: 2016-05-27-raspbian-jessie-lite.img
    offset_boot: 4194304
    offset_root: 70254592
# ---

Then run the playbook:

sudo ansible-playbook playbook.yml

You'll probably need adding some gigabytes to the image:

sudo dd if=/dev/zero bs=10MiB of=2016-05-27-raspbian-jessie-lite.img conv=notrunc oflag=append count=100

You can resize the partition with

sudo fdisk 2016-05-27-raspbian-jessie-lite.img

then delete and recreate the second Linux-partition with the same start-sector.

With resize2fs /dev/loopX (loopX = the mounted root filesystem) you can do an online resize of the filesystem.

For suspending and resuming the virtual machine in order to restore the /vagrant - shared folder you can use:

• vagrant suspend
• vagrant resume

After you stopped the machine you can restart it with

• vagrant reload

If you get many file errors during usage of the image mounted from the shared /vagrant - folder at /opt/raspberry/root (I do) you can also copy the raspberry-image to /home/vagrant and at the next bootup (poweroff and restart via Virtual Box in order not to link the /vagrant - shared folder) remove this empty /vagrant directory and make your own symlink by

sudo rmdir /vagrant
sudo ln -s /home/vagrant /vagrant

After a while a cron-script (/etc/cron.d/opt_raspberrypi_root) will mount /opt/raspberrypi/boot again from the image.

For making the Pi boot from the NFS-Pi-image it is sufficient to copy /opt/raspberrypi/boot/cmdline.txt to the first partition of your SD-card, if it already contained a Raspbian Jessie-image. This will make your Pi mount the image in /vagrant of your virtual machine as root.

Probably after a reboot you can reach your Pi with

ssh pi@192.168.178.201

If it won't connect in a reasonable time then you can try the NFS-server:

sudo mount 192.168.178.250:/opt/raspberrypi/root /mnt

and resetting the NFS-server:

sudo /etc/init.d/nfs-kernel-server restart

Next:

• Setting up distcc

---

1

• https://github.com/twobitcircus/rpi-build-and-boot/blob/master/README.md
• https://github.com/chilcano/vagrant-rpi-build-and-boot/blob/master/README.md ↩

2

• please replace 192.168.178 in vagrantfile and playbook.yml if your router uses another subnet ↩