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Updated README.
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Peter Bouda committed Jun 3, 2015
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Expand Up @@ -7,13 +7,13 @@ is the Raspberry Pi (A, B(+) and 2).
The following procedure will create a Buildroot environment that allows you to
compile Qt applications for the platforms supported by Buildroot. It will also
create a root filesystem for the target platform that contains a basic embedded
Linux environment and the Qt libraries. If you want to use the root filesystem
Linux environment and the Qt libraries. If you want to use the root file system
you will need a SD card. This repository contains an installation script for
the Raspberry Pi partition layout that will copy the root filesystem to the SD
the Raspberry Pi partition layout that will copy the root file system to the SD
card. It starts the Buildroot Linux system with an SSH daemon. This setup
allows you to develop Qt applications with the Qt Creator on your host system
and then deploy to the Raspberry. Developing Qt applications for the Raspberry
never was easier!
has never been easier!

* Buildroot project: http://buildroot.net/
* Qt project: http://www.qt.io/
Expand Down Expand Up @@ -48,7 +48,7 @@ Network connections via SSL/TLS are supported.

For graphical output the system supports LinuxFB and EGLFS. The latter is the
default. For more information about the configuration of the platform plugins
and Qt on embedded platform please visit:
and Qt on embedded platforms please visit:

http://doc.qt.io/qt-5/embedded-linux.html

Expand All @@ -60,7 +60,7 @@ tools and the init system. It is a very basic system that you may adapt to your
needs via the Buildroot configuration system. Besides Qt, the following
libraries and applications are built and installed:

* Several SSL/TLS libaries
* SSL/TLS libaries
* Image format libraries (JPEG, PNG, etc.)
* Some fonts
* GStreamer with ALSA support (for the Qt multimedia module)
Expand All @@ -70,13 +70,14 @@ libraries and applications are built and installed:
You can see a full list of the packages that are enabled in the file
`config/buildroot-raspi.conf`.

In addition to Buildroot's default init scripts there a two daemons started:
In addition to Buildroot's default init scripts the scripts of this repository
install and start two daemons:

* An NTP daemon to set the current date/time
* The Dropbear SSH daemon

The script in `scripts/postbuild.sh` is responsible to copy the two init scripts
to the root filesystem after building everything. It is automatically called
to the root file system after building everything. It is automatically called
by Buildroot. The two init scripts are in `userland/target`.


Expand Down Expand Up @@ -110,35 +111,38 @@ Buildroot configuration file to set all options that we need. Enter the
If you want to build the system for Raspberry A/B(+) then choose the "-raspi"
configuration file during this step:

$ cd buildroot
$ cd buildroot-2015.05
$ make defconfig BR2_DEFCONFIG=../config/buildroot-raspi.conf


### Adding NTP daemon

As the Raspberry does not have a realtime clock, our embedded system start an
NTP daemon to set the current date and time. Qt will use the date to validate
the SSL certificate of your ownCloud server, if the connection is encrypted.
As the embedded system uses buildroot's busybox, we will just add the ``ntpd``
option to the busybox configuration. Start the menu configuration of busybox:
As the Raspberry does not have a realtime clock, our embedded system will start
an NTP daemon to set the current date and time. Qt will use the date to validate
the SSL certificate, for example. As the embedded system uses buildroot's
busybox, we will just add the ``ntpd`` option to the busybox configuration.
Start the menu configuration of busybox:

$ make busybox-menuconfig

In the menu choose the option `Networking Utilities -> ntpd`. Exit and save.


### Start the build process

You can now start the build process. This will download and build Linux and all
libraries and applications. The whole procedure might take a while, up to a few
hours. Just run:
You can now start the build process. This will download and build the toolchain,
Linux and all libraries and applications. The whole procedure might take a
while, up to a few hours. Just run:

$ make

Buildroot will put all results of the build process in the folder `output`.


## Install root filesystem on SD card for Raspberry

In this step we will install the root file system on a SD card that will boot
a Raspberry. Buildroot put the file system into a folder `output/images`. We
the Raspberry. Buildroot put the file system into a folder `output/images`. We
will extract the image from there. But first, we have to prepare the SD card
with a specific partition layout for the Raspberry.

Expand All @@ -147,34 +151,33 @@ with a specific partition layout for the Raspberry.

The SD card has to co be prepared with a certain partition layout in order to
be bootable on the Raspberry. The standard layout is a small FAT partition and
a larger ext4 partition in this order. The easiest way to get prepare the card
in this way is to install a standard Raspbian on the card. This will also
install the mandatory binary firmware and license to boot the Raspberry. You
can find information about the process on the Raspberry download page:
a larger ext4 partition in this order. The easiest way to prepare the card is
to install a standard Raspbian on the card. This will also install the
mandatory binary firmware and license to boot the Raspberry. You can find
information about the process on the Raspberry download page:

https://www.raspberrypi.org/downloads/

Just follow the instructions given on the page under the Raspbian heading.
Just follow the instructions given on the page under the `Raspbian` heading.


### Modify and run installation script

To install the root file system we will now format the second partition on the
SD card with an ext4 file system and copy the Buildroot kernel onto the first
FAT partition. The repository has file `script/installrootfs.sh` that executes
all commands. This script needs to know the device of your SD card. Please check
carefully which device your SD card uses and adapt the script. Currently the
device for the SD card is `/dev/sdX`. Change those device names to your setup
*in all locations*.
SD card with an ext4 file system, extract the file system that Buildroot created
and copy the Buildroot kernel onto the first FAT partition. The repository
contains the file `script/installrootfs.sh` that executes all commands. The
script needs to know the device of your SD card. Please check carefully which
device your SD card uses and adapt the script. Currently the device for the SD
card is `/dev/sdX`. Change those device names to your setup *in all locations*.

If your SD card is still mounted from the previous step you might just call
`mount` to see a list of all file systems. Find your SD card in this list and
use the device names that are listed (like `/dev/sdc1` and `/dev/sdc2`).

*Careful: Your SD card has to prepared with the two Raspberry partitions and
should be mounted for the following steps. If you do not edit the script
`installrootfs.sh` with the correct device names your hard disk might get
formatted!*
*Careful: Your SD card has to prepared with the two Raspberry partitions. If
you do not edit the script `installrootfs.sh` with the correct device names
your hard disk might get formatted!*

You can now run the script. The script expects the path to the root file system
image and the kernel as the first argument. Buildroot puts those in the folder
Expand Down

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