[Docker] allow setting host build dir with FINN_HOST_BUILD_DIR

docs/finn/getting_started.rst

@@ -105,6 +105,7 @@ These are summarized below:
 * ``PYNQ_IP`` and ``PYNQ_PORT`` (or ``ALVEO_IP`` and ``ALVEO_PORT``) specify ip address and port number to access the PYNQ board / Alveo target
 * ``PYNQ_USERNAME`` and ``PYNQ_PASSWORD`` (or ``ALVEO_USERNAME`` and ``ALVEO_PASSWORD``) specify the PYNQ board / Alveo host access credentials for the test suite. For PYNQ, password is always needed to run as sudo. For Alveo, you can leave the password empty and place your ssh private key in the ``finn/ssh_keys`` folder to use keypair authentication.
 * ``PYNQ_TARGET_DIR`` (or ``ALVEO_TARGET_DIR``) specifies the target dir on the PYNQ board / Alveo host for the test suite
+* (optional) ``FINN_HOST_BUILD_DIR`` specifies which directory on the host will be used as the build directory. Defaults to ``/tmp/finn_dev_<username>``
 
 Supported Hardware
 ===================

run-docker.sh

@@ -95,18 +95,18 @@ SCRIPTPATH=$(dirname "$SCRIPT")
 : ${ALVEO_TARGET_DIR="/tmp"}
 : ${XILINX_XRT="/opt/xilinx/xrt"}
 : ${PLATFORM_REPO_PATHS="/opt/xilinx/platforms"}
+: ${FINN_HOST_BUILD_DIR="/tmp/$DOCKER_INST_NAME"}
 
-BUILD_LOCAL=/tmp/$DOCKER_INST_NAME
+FINN_CONTAINER_BUILD_DIR=/tmp/$DOCKER_INST_NAME
 VIVADO_HLS_LOCAL=$VIVADO_PATH
-VIVADO_IP_CACHE=$BUILD_LOCAL/vivado_ip_cache
+VIVADO_IP_CACHE=$FINN_CONTAINER_BUILD_DIR/vivado_ip_cache
 
 # ensure build dir exists locally
-mkdir -p $BUILD_LOCAL
-mkdir -p $VIVADO_IP_CACHE
+mkdir -p $FINN_HOST_BUILD_DIR
 mkdir -p $FINN_SSH_KEY_DIR
 
 gecho "Instance is named as $DOCKER_INST_NAME"
-gecho "Mounting $BUILD_LOCAL into $BUILD_LOCAL"
+gecho "Mounting $FINN_HOST_BUILD_DIR into $FINN_CONTAINER_BUILD_DIR"
 gecho "Mounting $VIVADO_PATH into $VIVADO_PATH"
 gecho "Mounting $VITIS_PATH into $VITIS_PATH"
 gecho "Port-forwarding for Jupyter $JUPYTER_PORT:$JUPYTER_PORT"
@@ -148,7 +148,7 @@ DOCKER_EXEC="docker run -t --rm --name $DOCKER_INST_NAME $DOCKER_INTERACTIVE --i
 DOCKER_EXEC+="--hostname $DOCKER_INST_NAME "
 DOCKER_EXEC+="-e SHELL=/bin/bash "
 DOCKER_EXEC+="-v $SCRIPTPATH:/workspace/finn "
-DOCKER_EXEC+="-v $BUILD_LOCAL:$BUILD_LOCAL "
+DOCKER_EXEC+="-v $FINN_HOST_BUILD_DIR:$FINN_CONTAINER_BUILD_DIR "
 DOCKER_EXEC+="-v $FINN_SSH_KEY_DIR:/home/$DOCKER_UNAME/.ssh "
 DOCKER_EXEC+="-e FINN_INST_NAME=$DOCKER_INST_NAME "
 DOCKER_EXEC+="-e FINN_ROOT="/workspace/finn" "