[PATCH] doc/raspberrypi: Added instructions for raspberrypi

[Christian Mauderer]

Hello Niteesh,

thanks for extending the documentation. That's very valuable.

I had some white space bugs again when applying:

`````
.git/rebase-apply/patch:68: trailing whitespace.

.git/rebase-apply/patch:77: trailing whitespace.
     arm-rtems5-gdb hello.exe
.git/rebase-apply/patch:85: trailing whitespace.

.git/rebase-apply/patch:86: trailing whitespace.

.git/rebase-apply/patch:85: new blank line at EOF.
+
`````

It's possible that for some code block it's necessary but there are at
least two that are not necessary.

For my workflow it was very useful to enable colors in git to get rid of
most of these errors. You can do that by the following command:

    git config --global color.ui auto

With this you very clear red marks for white space errors in "git diff"
and similar commands.

Depending on your editor you might can enable some visual hints right in
the editor too.

On 05/01/2020 13:46, G S Niteesh wrote:
> Added instructions to run examples on raspberrypi.
> ---
>  user/bsps/arm/raspberrypi.rst | 75 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 74 insertions(+), 1 deletion(-)
> 
> diff --git a/user/bsps/arm/raspberrypi.rst b/user/bsps/arm/raspberrypi.rst
> index 4ef75bd..653f8a7 100644
> --- a/user/bsps/arm/raspberrypi.rst
> +++ b/user/bsps/arm/raspberrypi.rst
> @@ -5,4 +5,77 @@
>  raspberrypi
>  ===========
>  
> -TODO.
> +This BSP support's `raspberrypi 1` and `raspberrypi 2` currently.
I think the official form is "Raspberry Pi X". At least it's used in
that form on the start page of raspberrypi.org.

> +The support for `raspberrypi 3` is work under progress.
> +The default bootloader on the raspberrypi which is used to boot raspbian
> +or other OS can be also used to boot RTEMS. U-boot can also be used
> +but it a personal preferance.

"preference" (I think?)

> +
> +Setup up SD card
> +----------------
> +
> +The raspberrypi's have an unconventional booting mechanism. The GPU
> +boots first, initializes itself, runs the bootloader and start the CPU.
> +The bootloader looks for a kernel image, by default the kernel images must
> +have name of form `kernel*.img` but this can be changed by adding `kernel=<img_name>`

Please try to keep 80 Characters when possible. In this case break
before `kernel...

> +to config.txt.
> +
> +You must provide the required files for the GPU to proceed. These files
> +can be downloded from this link https://github.com/raspberrypi/firmware/tree/master/boot

"downloaded"

80 Characters again.

> +.You can remove the kernel*.img if you want, but don't touch the other files.

The dot should have one space to "You" and it should be in one line
together with the previous sentence.

> +
> +Copy these files in to a SD card with FAT filesystem.
> +
> +Kernel image
> +------------
> +
> +We will be running the hello.exe on raspberrypi 2. Other examples can be

Is there a reason why you emphasized the board name above but not here?

It's not limited to the samples from the RTEMS tests. So maybe change
that to something like:

"The following steps show how to run hello.exe on a Raspberry Pi 2.
Other executables can be processed in a similar way."

> +found under testsuites.
> +
> +To create the kernel image:
> +
> +.. code-block:: none
> +
> +     arm-rtems5-objcopy -Obinary hello.exe kernel.img
> +
> +Copy the kernel image to the SD card.
> +
> +Make sure you have these lines below in your config.txt.
> +
> +.. code-block:: none
> +
> +     enable-uart=1
> +     kernel_address=0x200000
> +     kernel=kernel.img
> +
> +Testing
> +-------
> +
> +Qemu along with GDB can be used for debugging, but it only supports
> +``raspberrpi2`` and emulation is also incomplete. So some of the features

Again a different style for the board name.

> +might not work as expected.
> +
> +Make sure you have latest version of qemu, older ones don't support
> +raspberrypi.

I'm not a native speaker but that sentence somehow sounds odd. Are you
sure it's correct?

> +
> +.. code-block:: none
> +     
> +     qemu-system-arm -M raspi2 -m 1G -kernel hello.exe -serial mon:stdio -nographic -S -s
> +
> +This starts qemu and creates a socket at port ``1234`` for GDB to connect.
> +
> +In a new terminal, run GDB using
> +
> +.. code-block:: none
> +
> +     arm-rtems5-gdb hello.exe     
> +     tar remote:1234
> +     load
> +
> +This will connect GDB to qemu and loads the application.
> +
> +**Note**: Add ``set scheduler-locking on`` in GDB if you have any issues running
> +the examples.
> +     
> +     
> +
>