up2: update README to include more complete setup information

Signed-off-by: Ron Evans <[email protected]>

platforms/upboard/up2/README.md

@@ -8,16 +8,41 @@ For more info about the UP2 Board, go to [http://www.up-board.org/upsquared/](ht
 
 ### Setting up your UP2 board
 
-We recommend updating to the latest Ubuntu and firmware when using the UP2 board. For more information go to:
+We recommend updating to the latest Ubuntu 16.04 and BIOS v3.3 when using the UP2 board. To update your UP2 OS go to:
 
-URL
+https://downloads.up-community.org/download/up-squared-iot-grove-development-kit-ubuntu-16-04-server-image/
 
-Once your UP@ has been updated, you will need to provide permission to the `upsquared` user to access the I2C subsystem on the board. To do this, run the following command:
+To update your UP2 BIOS, go to:
+
+https://downloads.up-community.org/download/up-squared-uefi-bios-v3-3/
+
+Once your UP@ has been updated, you will need to provide permission to the `upsquared` user to access the GPIO or I2C subsystems on the board. 
+
+To access the GPIO subsystem, you will need to create a new group, add your user to the group, and then add a UDEV rule.
+
+First add a new UDEV rule to the UP2 board. Add the following text as a new UDEV rule named `/etc/udev/rules.d/99-gpio.rules`:
+
+```
+SUBSYSTEM=="gpio*", PROGRAM="/bin/sh -c '\
+        chown -R root:gpiouser /sys/class/gpio && chmod -R 770 /sys/class/gpio;\
+        chown -R root:gpiouser /sys/devices/virtual/gpio && chmod -R 770 /sys/devices/virtual/gpio;\
+        chown -R root:gpiouser /sys$devpath && chmod -R 770 /sys$devpath\
+'"
+```
+
+```
+sudo groupadd gpio
+sudo adduser upsquared gpio
+```
+
+To access the I2C subsystem, run the following command:
 
 ```
 sudo usermod -aG i2c upsquared
 ```
 
+You should reboot your UP2 board after making these changes for them to take effect.
+
 **IMPORTANT NOTE REGARDING I2C:** 
 The current UP2 firmware is not able to scan for I2C devices using the `i2cdetect` command line tool. If you run this tool, it will cause the I2C subsystem to malfunction until you reboot your system. That means at this time, do not use `i2cdetect` on the UP2 board.