add setup note

old-commit-hash: 0e059f5d4a

tools/webcam/README.md

@@ -16,7 +16,9 @@ cd ~
 git clone https://github.com/commaai/openpilot.git 
 # Follow [this readme](https://github.com/commaai/openpilot/tree/master/tools) to install the requirements 
 # Add line "export PYTHONPATH=$HOME/openpilot" to your ~/.bashrc 
-# You may also need to install tensorflow-gpu 2.0.0 
+# You also need to install tensorflow-gpu 2.0.0 and nvidia drivers: nvidia-xxx/cuda10.0/cudnn7.6.5 
+# Install [OpenCL Driver](https://www.codeproject.com/Articles/1230011/OpenCL-Drivers-and-Runtimes-for-Intel-Architectu) 
+# (Note: the code assumes cl platforms order to be 0.GPU/1.CPU when running clinfo; if reverse, change the -1 to -2 in selfdrive/modeld/modeld.cc#L130; helping us refactor this mess is encouraged) 
 # Install [OpenCV4](https://www.pyimagesearch.com/2018/08/15/how-to-install-opencv-4-on-ubuntu/) 
 ```
 ## Build openpilot for webcam
@@ -36,7 +38,7 @@ touch prebuilt
 cd ~/openpilot/tools/webcam 
 ./accept_terms.py # accept the user terms so that thermald can detect the car started 
 cd ~/openpilot/selfdrive 
-PASSIVE=0 NOSENSOR=1 ./manager.py 
+PASSIVE=0 NOSENSOR=1 WEBCAM=1 ./manager.py 
 # Start the car, then the UI should show the road webcam's view 
 # Adjust and secure the webcams (you can run tools/webcam/front_mount_helper.py to help mount the driver camera)
 # Finish calibration and engage!