Add support to compile from source on a Raspberry Pi

Update CMakeLists.txt to test if the CMAKE_SYSTEM_PROCESSOR variable is
either armv6l or armv7l. If so, add libGLESv2 to the list of libraries
to be linked to support openGL on embedded systems.

Update INSTALL file to list the packages needed to be installed on
Raspian Stretch or Ubuntu Mate to successfully compile subsurface from
source.

Signed-off-by: Doug Junkins <junkins@foghead.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/INSTALL b/INSTALL
index 5e211b9bc..184dc2d97 100644
--- a/INSTALL
+++ b/INSTALL
@@ -180,6 +180,22 @@ sudo apt install \
 	qtpositioning5-dev qtscript5-dev qttools5-dev qttools5-dev-tools \
 	qtquickcontrols2-5-dev
 
+On Raspberry Pi (Raspian Stretch and Ubuntu Mate 16.04.2) this seems to work
+
+sudo apt install \
+	autoconf automake cmake g++ git libcrypto++-dev libcurl4-gnutls-dev \
+	libgit2-dev libqt5qml5 libqt5quick5 libqt5svg5-dev libqt5webkit5-dev \
+	libsqlite3-dev libssh2-1-dev libssl-dev libssl-dev \
+	libtool libusb-1.0-0-dev libxml2-dev libxslt1-dev libzip-dev make \
+	pkg-config qml-module-qtlocation qml-module-qtpositioning \
+	qml-module-qtquick2 qt5-default qt5-qmake qtchooser \
+	qtconnectivity5-dev qtlocation5-dev qtpositioning5-dev qtscript5-dev \
+	qttools5-dev qttools5-dev-tools
+
+Note that on Ubuntu Mate 16.04.2 on the Raspberry Pi, you may need to configure
+some swap space in order for the build to complete successfully. There is no
+swap space configured by default. See the dphys-swapfile package.
+
 On PCLinuxOS you appear to need the following packages
 
 su -c "apt-get install -y autoconf automake cmake libtool gcc-c++ git \