1st gfortran stanza target for raspberry pi (add aarch64 and armv7l)

[davegill]

TYPE: new feature

KEYWORDS: raspberry pi

SOURCE: Daniel Zurawski and internal

DESCRIPTION OF CHANGES:
Additional strings, armv7l and aarch64, have been added to the first gfortran configuration stanza
so that these may be keywords for search from Raspberry Pi's uname -a output. No new
stanza was added for the gfortran target, so no re-numbering is required for existing scripts that
are reliant on such things as "32 = Gfortran for Linux with a serial build".

Associated with this PR, #1300 (Inconsistent arg types (integer kind) across subroutine call) is
also required to get the Raspberry Pi to build successfully.

LIST OF MODIFIED FILES:
modified: arch/configure.defaults

TESTS CONDUCTED:

1. Previously, a Raspberry Pi build returned this:

*********************************************************
***              ERROR ERROR ERROR ERROR              ***
***                                                   ***
*** Configuration not found in configure.defaults     *** 
*********************************************************

2. After this PR, the configure command is able to find a target (raspian buster):

-----------------------------------------------------------------------
Please select from among the following Linux armv7l options:
    
  1. (serial)   2. (smpar)   3. (dmpar)   4. (dm+sm)   GNU (gfortran/gcc)

3. After this PR, the configure command is able to find a target (ubuntu mate):

------------------------------------------------------------------------
Please select from among the following Linux aarch64 options:

  1. (serial)   2. (smpar)   3. (dmpar)   4. (dm+sm)   GNU (gfortran/gcc)

4. Jenkins testing is all pass.

RELEASE NOTES: Modifications to the WRF code now permit the model to be built on a Raspberry Pi with the GNU/8 compiler.

[djzurawski]

I am running 64bit Ubuntu Mate for Raspberry Pi on a Raspberry Pi 4 and get aarch64 from uname -a. Maybe add that arch too

[davegill]

@djzurawski
This is EXACTLY the sort of benefit that we hoped would come from this open development.

[davegill]

@djzurawski
Dan,
Would you please verify that this successfully brings up a set of possible build options for you.

[djzurawski]

Yep got build options

pi@raspberry4:~/wrftest/WRF$ uname -a
Linux raspberry4 5.4.0-1022-raspi #25-Ubuntu SMP PREEMPT Thu Oct 15 13:31:49 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux
pi@raspberry4:~/wrftest/WRF$ ./configure
checking for perl5... no
checking for perl... found /usr/bin/perl (perl)
Will use NETCDF in dir: /home/pi/WRF/Library
Will use HDF5 in dir: /home/pi/WRF/Library
PHDF5 not set in environment. Will configure WRF for use without.
Will use 'time' to report timing information


If you REALLY want Grib2 output from WRF, modify the arch/Config.pl script.
Right now you are not getting the Jasper lib, from the environment, compiled into WRF.

------------------------------------------------------------------------
Please select from among the following Linux aarch64 options:

  1. (serial)   2. (smpar)   3. (dmpar)   4. (dm+sm)   GNU (gfortran/gcc)

Enter selection [1-4] : 

[davegill]

@djzurawski
Dan,
Please send me your name and affiliation, so that I may add it to the PR commit message.

[djzurawski]

@djzurawski
Dan,
Please send me your name and affiliation, so that I may add it to the PR commit message.

Daniel Zurawski. Unaffiliated?