pru: Add documentation and install scripts for running on the PRU

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

scripts/install-beaglebone.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+# This script installs Klipper on a Beaglebone running Debian Jessie
+# for use with its PRU micro-controller.
+
+# Step 1: Do main install
+install_main()
+{
+    # Run the octopi script - raspbian is close enough to debian for
+    # this to work.
+    ${SRCDIR}/scripts/install-octopi.sh
+}
+
+# Step 2: Install additional system packages
+install_packages()
+{
+    # Install desired packages
+    PKGLIST="gcc-pru"
+
+    report_status "Installing beaglebone packages..."
+    sudo apt-get install --yes ${PKGLIST}
+}
+
+# Step 3: Install startup script
+install_script()
+{
+    report_status "Installing pru start script..."
+    sudo cp "${SRCDIR}/scripts/klipper-pru-start.sh" /etc/init.d/klipper_pru
+    sudo update-rc.d klipper_pru defaults
+}
+
+# Step 4: Install pru udev rule
+install_udev()
+{
+    report_status "Installing pru udev rule..."
+    sudo /bin/sh -c "cat > /etc/udev/rules.d/pru.rules" <<EOF
+KERNEL=="rpmsg_pru30", MODE="0666"
+EOF
+}
+
+# Helper functions
+report_status()
+{
+    echo -e "\n\n###### $1"
+}
+
+verify_ready()
+{
+    if [ "$EUID" -eq 0 ]; then
+        echo "This script must not run as root"
+        exit -1
+    fi
+}
+
+# Force script to exit if an error occurs
+set -e
+
+# Find SRCDIR from the pathname of this script
+SRCDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )"/.. && pwd )"
+
+# Run installation steps defined above
+verify_ready
+install_main
+install_packages
+install_script
+install_udev