Compilation and Installation

Procedure

Use SVN to check out and obtain the ROMS source code.
Create a folder and check out the ROMS source code to the folder. To obtain the source code, you need to register an account.
```
cd /path/to/ROMS
mkdir ROMS_4.0
svn checkout --username Account name --password Password https://www.myroms.org/svn/src/trunk ROMS_4.0
```
Example:

Check out the source code using HPC/Huawei12#$:

svn checkout --username HPC --password Huawei12#$ https://www.myroms.org/svn/src/trunk ROMS_4.0

The source code file structure is as follows:
Customize the build script.
1. To keep the source code unchanged, run the following commands to create a ROMSProjects folder for compiling and running ROMS. upwelling is the default test case included in the source package.
```
cd /path/to/ROMS
mkdir ROMSProjects
cd ROMSProjects
mkdir upwelling
cd upwelling
```
2. Copy the following files to the upwelling directory.
```
cp /path/to/ROMS/ROMS_4.0/ROMS/Bin/build_roms.sh .
cp /path/to/ROMS/ROMS_4.0/ROMS/External/roms_upwelling.in .
cp /path/to/ROMS/ROMS_4.0/ROMS/External/varinfo.dat .
cp /path/to/ROMS/ROMS_4.0/ROMS/Include/upwelling.h .
```
3. Edit the build_roms.sh file.
  1. Open the build_roms.sh file.
```
vi build_roms.sh
```
  2. Press i to enter the edit mode.
    - Set the ROMS root directory and upwelling path and modify the following content:
```
export ROMS_APPLICATION=UPWELLING
export MY_ROOT_DIR=/path/to/ROMS
export MY_PROJECT_DIR=${MY_ROOT_DIR}/ROMSProjects/upwelling
export MY_ROMS_SRC=/path/to/ROMS/ROMS_4.0
```
    - Set compilation options and modify the following content:
```
export USE_MPI=on
export USE_MPIF90=on
export which_MPI=openmpi
export FORT=flang
export USE_NETCDF4=on
```
      Comment out export USE_MY_LIBS=no and use export USE_MY_LIBS=yes.
  3. Press Esc, type :wq!, and press Enter to save the file and exit.
Edit the my_build_path.sh file.
1. Open the my_build_path.sh file.
```
cd /path/to/ROMS/ROMS_4.0/Compilers
vi my_build_path.sh
```
2. Press i to enter the edit mode and modify the file as follows:
  Change gfortran in line 83 to flang.
  
  Change MPI_ROOT in line 87 to MPI_ROOT=/path/to/hypermpi/hmpi.
  
  Change gfortran in lines 295 and 296 to flang.
  
  Change MPI_ROOT in line 311 to MPI_ROOT=/path/to/hypermpi/hmpi.
  
  Change NETCDF= in line 330 to NETCDF=/path/to/NETCDF.
  
  After performing 3.a, press Esc, type :set nu, and press Enter to display the line number.
3. Press Esc, type :wq!, and press Enter to save the file and exit.
Place the Linux-flang.mk file in /path/to/ROMS/ROMS_4.0/Compilers/.
```
cd /path/to/ROMS/ROMS_4.0/Compilers/
```
Compile Linux-flang.mk as follows:
```
cp Linux-gfortran.mk ../
mv Linux-gfortran.mk Linux-flang.mk
vi Linux-flang.mk
```
Modify it as follows:

Press Esc and type :wq! to save the file and exit.
Modify the roms_upwelling.in file.
1. Open the roms_upwelling.in file.
```
cd /path/to/ROMS/ROMSProjects/upwelling/
vi roms_upwelling.in
```
2. Press i to enter the edit mode and change the path of varinfo.dat in VARNAME.
```
VARNAME = /path/to/ROMS/ROMSProjects/upwelling/varinfo.dat
```
  Set NtileI and NtileJ. The product of NtileI and NtileJ must be equal to the value of np (number of cores).
  
  NtileI=2
  
  NtileJ=4
3. Press Esc, type :wq!, and press Enter to save the file and exit.
Perform the installation.
```
chmod 777 build_roms.sh
chmod 777 /path/to/ROMS/ROMS_4.0/ROMS/Bin/cpp_clean
chmod 777 /path/to/ROMS/ROMS_4.0/ROMS/Bin/sfmakedepend
./build_roms.sh -j
```
If the executable file romsM is generated in the directory and no error is reported during the installation, the installation is successful.

Parent topic: ROMS 4.0 Porting Guide (openEuler 21.03)