[RESEND] doc: bcm283x: update documentation for Raspberry Pi

[Roland Hieber]

The old way does not seem to work for RPi 3, as the UART pins are
mapped differently and the NOOBS bootcode does not seem to read a
config.txt.

Signed-off-by: Roland Hieber <r.hieber at pengutronix.de>
---
 Documentation/boards/bcm2835.rst | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)
---
Although Sascha said he had applied the patch, I cannot find traces of
it in the current master. It probably got lost, so I'm resending it.
Note that this patch is independent of Lucas' RPi patch series and also
applies to the current state of RPi support.

 - Roland

diff --git a/Documentation/boards/bcm2835.rst b/Documentation/boards/bcm2835.rst
index 13cebb01c4..1a78cfba3c 100644
--- a/Documentation/boards/bcm2835.rst
+++ b/Documentation/boards/bcm2835.rst
@@ -1,17 +1,35 @@
-Broadcom BCM2835
+Broadcom BCM283x
 ================
 
 Raspberry Pi
 ------------
 
-  1. Prepare a card with a FAT filesystem. Download a tiny NOOBS LITE
-     zip archive and unpack it into FAT partition.
-     See http://www.raspberrypi.org/help/noobs-setup/ for details.
+  1. Prepare an SD or microSD card with a FAT filesystem of at least 30 MB in size.
+       
+  2. Download the `Raspberry Pi firmware`_ (120 MB), unzip it, and copy the
+     contents of the ``boot/`` folder to your card.
 
-  2. Compile ``barebox.bin`` image (use ``rpi_defconfig``).
-     Copy it to the SD/microSD card and name it ``recovery.img``.
+  3. Use ``make rpi_defconfig; make`` to build barebox. This will create the following images:
 
-  3. Connect to board's UART (115200 8N1);
+     - ``images/barebox-raspberry-pi-1.img`` for the BCM2835/ARM1176JZF-S (Raspberry Pi 1)
+     - ``images/barebox-raspberry-pi-2.img`` for the BCM2836/CORTEX-A7 (Raspberry Pi 2)
+     - ``images/barebox-raspberry-pi-3.img`` for the BCM2837/CORTEX-A53 (Raspberry Pi 3, Raspberry Pi Zero)
+    
+     Copy the respective image for your model to your SD card and name it
+     ``barebox.img``.
+
+  4. Create a text file ``config.txt`` on the SD card with the following content::
+
+         kernel=barebox.img
+         enable_uart=1
+         dtoverlay=pi3-miniuart-bt
+
+     (For more information, refer to the `documentation for config.txt`_.)
+
+  5. Connect to board's UART (115200 8N1);
      Use PIN6 (GND), PIN8 (UART_TX), PIN10 (UART_RX) pins.
 
-  4. Turn board's power on.
+  6. Turn board's power on.
+
+.. _Raspberry Pi firmware: https://codeload.github.com/raspberrypi/firmware/zip/80e1fbeb78f9df06701d28c0ed3a3060a3f557ef
+.. _documentation for config.txt: https://www.raspberrypi.org/documentation/configuration/config-txt/
-- 
2.11.0