added SYSTYPE "Ubuntu" to Makefile

Makefile

@@ -37,6 +37,7 @@ CONFIGVARS := $(shell cat $(BUILD_DIR)/arepoconfig.h)
 RESULT     := $(shell SRC_DIR=$(SRC_DIR) BUILD_DIR=$(BUILD_DIR) ./git_version.sh)
 
 # Default
+MPICH_INCL =
 MPICH_LIB  = -lmpich
 GMP_LIB    = -lgmp
 GSL_LIB    = -lgsl -lgslcblas
@@ -63,6 +64,29 @@ HDF5_INCL = -I/opt/local/include -DH5_USE_16_API
 HDF5_LIB  = -L/opt/local/lib  -lhdf5 -lz
 HWLOC_INCL= -I/opt/local/include
 endif
+# end of Darwin
+
+# Ubuntu Linux
+ifeq ($(SYSTYPE),"Ubuntu")
+# compiler and its optimization options
+OPTIMIZE  =  -std=c11 -ggdb -O3 -Wall -Wno-format-security -Wno-unknown-pragmas -Wno-unused-function
+
+# overwrite default:
+MPICH_INCL= -I/usr/lib/x86_64-linux-gnu/openmpi/include/
+MPICH_LIB = -L/usr/lib/x86_64-linux-gnu/openmpi/lib/ -lmpi
+GSL_INCL  =
+GSL_LIB   = -lgsl -lgslcblas
+HWLOC_LIB = -lhwloc
+
+# libraries that are included on demand, depending on Config.sh options
+FFTW_INCL =
+FFTW_LIBS =
+HDF5_INCL = -I/usr/include/hdf5/serial/ -DH5_USE_16_API
+HDF5_LIB  = -L/usr/lib/x86_64-linux-gnu/hdf5/serial/ -lhdf5 -lz
+HWLOC_INCL=
+endif
+# end of Ubuntu
+
 
 # insert the library paths for your system here, similar to SYSTYPE "Darwin" above
 
@@ -292,7 +316,7 @@ endif
 #combine compiler options#
 ##########################
 
-CFLAGS = $(OPTIMIZE) $(HDF5_INCL) $(GSL_INCL) $(FFTW_INCL) $(HWLOC_INCL) -I$(BUILD_DIR)
+CFLAGS = $(OPTIMIZE) $(MPICH_INCL) $(HDF5_INCL) $(GSL_INCL) $(FFTW_INCL) $(HWLOC_INCL) -I$(BUILD_DIR)
 
 LIBS = $(GMP_LIB) $(MATH_LIB) $(MPICH_LIB) $(HDF5_LIB) $(GSL_LIB) $(FFTW_LIB) $(HWLOC_LIB)
 
@@ -388,4 +412,3 @@ $(BUILD_DIR)/Makefile.check: Makefile Template-Config.sh defines_extra check.py
 
 $(BUILD_DIR)/Config.check: Template-Config.sh check.py
 	@$(PYTHON) check.py 4 Template-Config.sh $@
-