diff --git a/README.md b/README.md
index a4681ea2e2844f03c3ed43b189b506a4ce856961..579533d011b88d46609f65db9d630c32204a1317 100644
--- a/README.md
+++ b/README.md
@@ -8,47 +8,6 @@ Just build AOSP - Fluoride is there by default.
Instructions for Ubuntu, tested on 14.04 with Clang 3.5.0 and 16.10 with Clang
3.8.0
-### Install required libraries
-
-```sh
-sudo apt-get install libevent-dev libc++-dev libc++abi-dev
-```
-
-### Install build tools
-
- - Install [ninja](https://ninja-build.org/) build system
-
-```sh
-sudo apt-get install ninja-build
-```
-
-or download binary from https://github.com/ninja-build/ninja/releases
-
- - Install [gn](https://chromium.googlesource.com/chromium/src/tools/gn/) -
- meta-build system that generates NinjaBuild files.
-
-Get sha1 of current version from [here](
-https://chromium.googlesource.com/chromium/buildtools/+/master/linux64/gn.sha1)
- and then download corresponding executable:
-
-```sh
-wget -O gn http://storage.googleapis.com/chromium-gn/<gn.sha1>
-```
-
-i.e. if sha1 is "3491f6687bd9f19946035700eb84ce3eed18c5fa" (value from 24 Feb
- 2016) do
-
-```sh
-wget -O gn http://storage.googleapis.com/chromium-gn/3491f6687bd9f19946035700eb84ce3eed18c5fa
-```
-
-Then make binary executable and put it on your PATH, i.e.:
-
-```sh
-chmod a+x ./gn
-sudo mv ./gn /usr/bin
-```
-
### Download source
```sh
@@ -57,6 +16,13 @@ cd ~/fluoride
git clone https://android.googlesource.com/platform/packages/modules/Bluetooth/system
```
+Install dependencies (require sudo access):
+
+```sh
+cd ~/fluoride/bt
+build/install_deps.sh
+```
+
Then fetch third party dependencies:
```sh
diff --git a/system/build/install_deps.sh b/system/build/install_deps.sh
new file mode 100755
index 0000000000000000000000000000000000000000..f1173a9ca3908ae1a7a3e3f2f04b6fff8f8aeab3
--- /dev/null
+++ b/system/build/install_deps.sh
@@ -0,0 +1,57 @@
+#!/bin/bash
+CLANG_PACKAGE=clang
+GNSHA1_URL="https://chromium.googlesource.com/chromium/buildtools/\
++/master/linux64/gn.sha1?format=TEXT"
+
+# Check if clang is already installed on current system
+clang_path=`which clang`
+if [ -f "$clang_path" ]; then
+ # if clang binary is avalable, check its version
+ clang_version=$($clang_path --version | grep clang | sed "s/.*version\s*\([0-9]*\.[0-9]*\).*/\1/")
+ IFS="." read -ra clang_version_array <<< "$clang_version"
+ clang_version_major=${clang_version_array[0]}
+ clang_version_minor=${clang_version_array[1]}
+ # if the version is greater than 3.5 then do not install clang here
+ if [ $clang_version_major -ge 3 ] && [ $clang_version_minor -ge 5 ]; then
+ echo "Detected clang $clang_version"
+ CLANG_PACKAGE=""
+ fi
+fi
+
+if [ ! -z "$CLANG_PACKAGE" ]; then
+ # Try to find clang from a known list
+ for clang_version in 3.9 3.8 3.7 3.6 3.5
+ do
+ clang_path=`which clang-$clang_version`
+ if [ -f "$clang_path" ]; then
+ echo "Detected clang-$clang_version"
+ CLANG_PACKAGE=""
+ break
+ fi
+ done
+fi
+
+if [ ! -z "$CLANG_PACKAGE" ]; then
+ echo "clang not found on current system, installing"
+ if [ -f /etc/lsb-release ]; then
+ # Ubuntu
+ ubuntu_version=$(lsb_release --release --short)
+ IFS="." read -ra ubuntu_version_array <<< "$ubuntu_version"
+ ubuntu_version_major=${ubuntu_version_array[0]}
+ ubuntu_version_minor=${ubuntu_version_array[1]}
+ if [ $ubuntu_version_major -lt 15 ]; then
+ echo "Choose clang-3.8 for Ubuntu 14 and below"
+ CLANG_PACKAGE=clang-3.8
+ fi
+ fi
+fi
+
+sudo apt-get -y install $CLANG_PACKAGE libevent-dev libc++-dev libc++abi-dev \
+ ninja-build
+gn_path=`which gn`
+if [ -z $gn_path ]; then
+ gnsha1=$(curl $GNSHA1_URL | base64 -d)
+ wget -O gn http://storage.googleapis.com/chromium-gn/$gnsha1
+ chmod a+x ./gn
+ sudo mv ./gn /usr/bin/
+fi
diff --git a/system/build/toolchain/clang/BUILD.gn b/system/build/toolchain/clang/BUILD.gn
index aed5c05355c1488b801dd10cb686569a35d65439..fcd6d5630bc1d466cad49dcfbd0d54c0268adbca 100644
--- a/system/build/toolchain/clang/BUILD.gn
+++ b/system/build/toolchain/clang/BUILD.gn
@@ -13,8 +13,15 @@
# See the License for the specific language governing permissions and
# limitations under the License.
#
-clang = "clang"
-clangxx = "clang++"
+clang_suffix = exec_script("get_clang_suffix.py", [], "list lines")
+clang_suffix = clang_suffix[0]
+assert(clang_suffix != "None",
+ "Cannot find clang, please install clang 3.5 or above")
+if (clang_suffix != "") {
+ clang_suffix = "-" + clang_suffix
+}
+clang = "clang$clang_suffix"
+clangxx = "clang++$clang_suffix"
config("clang_config") {
include_dirs = [
diff --git a/system/build/toolchain/clang/get_clang_suffix.py b/system/build/toolchain/clang/get_clang_suffix.py
new file mode 100644
index 0000000000000000000000000000000000000000..dedacdd51d325294994f7363b109196073150837
--- /dev/null
+++ b/system/build/toolchain/clang/get_clang_suffix.py
@@ -0,0 +1,43 @@
+import os
+import subprocess
+import re
+import sys
+
+def which(cmd):
+ for p in os.environ["PATH"].split(os.pathsep):
+ clang_path = os.path.join(p, cmd)
+ if os.path.exists(clang_path):
+ return clang_path
+ return None
+
+CLANG_VERSION_REGEX=".*version\s*([0-9]*\.[0-9]*)\.*"
+clang_path = which("clang++")
+clang_version_major = 0
+clang_version_minor = 0
+
+if clang_path:
+ clang_version_out = subprocess.Popen([clang_path, "--version"],
+ stdout=subprocess.PIPE).communicate()[0]
+ clang_version_match = re.search(CLANG_VERSION_REGEX, clang_version_out)
+ clang_version_str = clang_version_match.group(1)
+ clang_version_array = clang_version_str.split('.')
+ clang_version_major = int(clang_version_array[0])
+ clang_version_minor = int(clang_version_array[1])
+
+if clang_version_major >= 3 and clang_version_minor >= 5:
+ print ""
+else:
+ # Loop in support clang version only
+ clang_version_major = 3
+ clang_version_minor = 9
+ while clang_version_major >= 3 and clang_version_minor >= 5:
+ clang_version_str = "%d.%d" % (clang_version_major, clang_version_minor)
+ clang_path = which("clang++-" + clang_version_str)
+ if clang_path:
+ print clang_version_str
+ sys.exit(0)
+ clang_version_minor -= 1
+ if clang_version_minor < 0:
+ clang_version_minor = 9
+ clang_version_major -= 1
+ print "None"