- remove spaces at the end of lines
- remove useless dead code
  use: git show -p <this commit> -w
  to see it clearly

With value 4 when connecting one UE and doing some downlink
iperf TCP there is a crash. Probably due to the multiple wrong
RA detected leading to uplink failure of fake UE that never
sends Msg3 (because, well, there is no other UE).

This is another problem that will be fixed at some point.

Anyway, this value 4 fails. Let's put back 3.

Doing airplane mode off to connect a cots UE followed by airplane mode on
to disconnect it gives very bad results (bad disconnection with lots of
UL failures followed by lots of logs in the eNB). It used to work properly
after the work done by Xu Bo.

It turns out that in 2018.w04 things were still working okay. But
in 2018.w05 no.

So I ran:

    git diff 2018.w04 2018.w05

And I checked all the modifications that I thought were relevant
(everything related to the UE, oaisim, if4 and fapi has not been checked).

This commits takes back the version of 2018.w04.

The modifications in openair2/RRC/LITE/rrc_eNB.c are necessary, I think.

The other modifications may not be necessary or even wrong. To be checked
at some point.

The following compilation did not work anymore:

    ./build_oai --eNB -w USRP -r Rel10 -c

(Rel8 still does not work.)

- add function free_td() -> complements init_td() [seems to not be used, added
  for completeness]
- add function free_td8() -> undoes init_td8() [free memory of 8-bit LLR Turbo
  decoder]
- add function free_td16() -> undoes init_td16() [free memory of 16-bit LLR
  Turbo decoder]
- change function free_tdavx216() -> undoes init_tdavx216() [free memory of
  16-bit LLR Turbo decoder, AVX2 version]
- add free_lte_top() -> frees memory allocated by init_lte_top()
- change free_ul_ref_sigs() to set freed pointers to NULL
- add method free_transport() -> frees memory of ULSCH/DLSCH transport channels
- use the above functions when stopping/restarting the lte-softmodem

this methods free the memory that is allocated by the functions
phy_init_RU() and phy_init_lte_eNB()

As reported by Emad Alizade:

    According to "Issue255 256 257 paging reesta release" that has been
    merged in develop version, we have a question: In rrc_eNB_free_UE()
    function only all ulsch related memory of user has been cleaned, but
    I think not only ulsch memory but also dlsch memory must be cleaned.
    I tested the latest develop version and with repetition UE attach-detach
    procedures we find that the dlsch memory has not been cleaned and after
    repeat this sequence (45 times) assertion with cause UE_id!=-1 (no free
    or exiting dlsch_context, dci_tools.c: fill_dci_and_dlsch() ) occurred
    and no UE will be attached to system.

The fixes in this commit are from Emad Alizade.

fixes after merge with develop. Partial UE/eNB separation in build to avoid problems with NFAPI in oaisim UE/RRU.
tested with simulator.

Fix #582, RTAI, RTAI_ENABLED, ENABLE_RTAI_CLOCK, RTAI_ISNT_POSIX, _RTAI_MATH_H, CELLULAR, TIMER_ONESHOT_MODE, EMOS, EMOS_CHANNEL, OAI_EMU, OPENAIR_EMU, PHY_ABSTRACTION, PHY_ABSTRACTION_UL removed

This commit fixes issues introduced by the previous commit.

Summary of work:
- cleanup:
  - fix LOG_XX to be less verbose
  - fix cmake_targets/CMakeLists.txt
  - fix oaienv
  - remove dead code
- bug fixes:
  - in openair1/SCHED/fapi_l1.c we had:
      eNB->pdcch_vars[subframe&1].num_dci           = number_dci;
    should be:
      eNB->pdcch_vars[subframe&1].num_dci           = 0;
    This bug let the PHY send more DCIs than what should have been
    sent because num_dci is incremented later on in the code.
    This fix may be a problem for fapi mode, to be checked.
  - add new T VCD traces
  - revert openair1/PHY/TOOLS/file_output.c to 'develop' version
  - remove thread_id in logRecord/logRecord_mt
  - revert (and adapt) configuration files
  - be careful when doing frame++, we need to % 1024
  - revert target_rx_power in openair2/LAYER2/MAC/eNB_scheduler_ulsch.c
- NFAPI:
  - the open-nFAPI code has been included in the repository. See nfapi/README.
    Maybe we should "git clone" the Cisco repository instead. We have to be
    careful of availability though.

What has been tested:
- monolithic eNB FDD 5/10MHz with one UE, iperf UDP/TCP uplink/downlink

Anything else may fail to work, especially the FAPI mode, which has not
been tested at all.

It has been chosen to not include the full history of commits
from David. He included a binary version of wireshark, probably
a modified one that understands NFAPI. Wireshark is released under
the GPL license, we cannot include it in the repository. We could
have done a next commit to remove this binary. But then it would
still be present in the history of commits, which may not be allowed.
And it would take space on disk. We could edit the history to remove
wireshark entirely. But this operation is too complicated.

There was also a pcap capture file, which has nothing to do in
the history of commits and would take space on disk. There again,
it's too difficult to edit the history to remove it.

There was a file .gitignore that was also removed.

The original history can be found on David's repository:
https://gitlab.eurecom.fr/daveprice/openairinterface5g/
The branch is: nfapi-ru-rau-split.

A copy of that branch has been included in the internal OAI
repository, for those who have access to it.
The branch is the same. The last commit ID is
9106438239e0bc626ff1fa1d97d911caadd0fbb9.

You can compare the current commit with the commit 9106...
to see what differs.

The current commit has to be considered non-working.
The commit following the current commit will fix problems with
the work in the current commit.

If you use git bisect, don't spend time analyzing the current
commit.

The problem is the following (as reported by an user):

  "one UE is attached to OAI system. UE is near the antenna. Try to detach
  the UE and attach again. Repeat this procedure for 5-6 times. OAI system
  does not work and any the UE can not attach to this system. I use TEMS
  software and I can see MIB signaling on this UE but UE can not decode SIB1
  and SIB2."

What happens is that the DCI for SIB1 and SIB2 is not cleared before
use. That is the bits in the 'padding' field keep the values that were
set before. If the structure has been used to transmit other DCIs
(eg. for UEs) in the past, it may be reused with some of those bits set
to 1. When receiving this DCI, the UE won't accept it because it
gets some bits at 1 where it expects them to be 0.

The short-term/quick solution is to clear the 'padding' field.
A better solution would be to rewrite this part of the code,
which is way too complicated for what it does. But this takes
too much time.

In dci.h the field 'dummy' of some structures was renamed to 'padding'.
The fields 'padding32' and 'padding64' were also renamed to 'padding'
for consistency.

Some structures (DCI2B_1_5MHz_TDD, DCI2B_10MHz_FDD, DCI2D_1_5MHz_FDD,
DCI2D_5MHz_FDD, DCI2D_10MHz_FDD) had a 'padding' field at the end, which
was renamed to 'padding0'. I don't know if this field should be here at all.
To me this field looks very suspicious. When we test DCIs 2B and 2D we
should be careful.

making oaisim_nos1 compile

merge the implemention of Paging, RRCConnectionRelease, RRCConnectionReestablishment, E-RAB Modify, E-RAB Release

- remove global variables in the function lte_est_timing_advance_pusch
- do the smoothing logic that was in lte_est_timing_advance_pusch
  in rx_sdu (is it necessary? is it correct?)
- put back the value 100 in prach_procedures for the test on prach energy
- change the value of timing_advance_update

  it was:

     timing_advance_update                  = sync_pos - eNB->frame_parms.nb_prefix_samples/4; //to check

  it is now:

     timing_advance_update                  = sync_pos; // - eNB->frame_parms.nb_prefix_samples/4; //to check

  this should be checked somehow. The computation looked suspicious. Maybe
  the new one is wrong.

just a quick fix before merge, the real solution
is to disable pusch scheduling in the prach, to be
done later