Add bringup for baremetal application

Signed-off-by: Saket Sinha <[email protected]>

source/baremetal.rst

@@ -0,0 +1,47 @@
+BareMetal Application
+=====================
+
+This example provides a minimal bare metal demo app that demonstrates how to easily create a bare metal C application
+and load it/run it on the riscv soc from  RaspberryPi `RP2350 <https://raspberrypi.com/products/rp2350/>`_.
+
+Here, we will focus on a printing simple string over serial console for simplicity and clarity.
+
+Setting up the environment
+--------------------------
+
+Please remember to set up pico-sdk and picotool alongwith and riscv toolchain first.
+The sdk and tools for rp2350 are installed in ~/.pico-sdk/ with `VSCode Plugin <https://github.com/raspberrypi/pico-vscode/>`_.
+It can also be installed with prebuilt binaries present at `pico-sdk-tools <https://github.com/raspberrypi/pico-sdk-tools/releases/tag/v2.0.0-2>`_.
+To use the tools and sdk installed to another location set the following :
+
+.. literalinclude:: scripts/baremetal.sh
+   :start-after: # set up env
+   :end-before: # /set up env
+
+Getting the sources
+-------------------
+
+Clone the baremetal application repository.
+
+.. literalinclude:: scripts/baremetal.sh
+   :start-after: # clone
+   :end-before: # /clone
+
+Building the baremetal application
+----------------------------------
+
+Execute the below commands:
+
+.. literalinclude:: scripts/baremetal.sh
+   :start-after: # build
+   :end-before: # /build
+
+.. note:: The resulting binaries (``print.uf2``) will be written in the ``build`` folder. Transfer this binary file to the Pico board with a micro USB cable and holding down the BOOTSEL button. 
+
+Running the baremetal application
+---------------------------------
+
+To run baremetal application, connect a bi-directional logic level converter set at 3.3V between development machine and Pico with TX, RX and GND.
+
+**RISC-V from RPI** should be seen on ttyUSB serial terminal.
+

source/index.rst

@@ -8,6 +8,12 @@
 
    introduction
 
+.. toctree::
+   :caption: BareMetal
+   :maxdepth: 1
+
+   baremetal
+
 .. toctree::
    :caption: Zephyr
    :maxdepth: 2

source/scripts/baremetal.sh

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+#!/bin/bash
+
+set -e
+
+# get prerequisites
+wget https://github.com/raspberrypi/pico-sdk-tools/releases/download/v2.0.0-2/pico-sdk-tools-2.0.0-x86_64-lin.tar.gz
+wget https://github.com/raspberrypi/pico-sdk-tools/releases/download/v2.0.0-2/riscv-toolchain-14-x86_64-lin.tar.gz
+wget https://github.com/raspberrypi/pico-sdk-tools/releases/download/v2.0.0-2/picotool-2.0.0-x86_64-lin.tar.gz
+# /get prerequisites
+
+# set up env
+export PICO_SDK_PATH=~/example_sdk/sdk/2.0.0/
+export PICO_TOOLCHAIN_PATH=~/example_sdk/toolchain/13_2_Rel1
+export picotool_DIR=~/example_sdk/picotool/2.0.0/picotool
+# /set up env
+
+# clone
+git clone https://github.com/disdi/bare-metal-riscv
+cd bare-metal-riscv
+# /clone
+
+# build
+make PICO_BOARD=sparkfun_promicro_rp2350 PICO_SDK_PATH=~/.pico-sdk/  build
+make flash
+# /build
+
+