Refactor cellular directory structure

[LDong-Arm]

Preceding PR: #13253 (merged)

Summary of changes

Move cellular from features/cellular to connectivity/cellular and cellular drivers to connectivity/drivers/cellular as per our directory structure proposal:

connectivity
├── [...]
├── cellular
│   ├── mbed_lib.json
│   ├── [...]
│   ├── include/cellular
│   │   └── framework
│   │       ├── API
│   │       ├── AT
│   │       ├── common
│   │       └── device
│   ├── source
│   │   └── framework
│   │       ├── AT
│   │       ├── common
│   │       └── device
│   └── tests
│       └── UNITTESTS
└── drivers
    ├── [...]
    └── cellular
        └── [...]

Note:

• There's no Greentea test dedicated to cellular.
• Files in UNITTESTS/stubs are shared across tests from different libraries and thus left untouched for now.
• For details, see individual commits.

Impact of changes

Migration actions required

Documentation

None.

---

Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

---

Test results

[] No Tests required for this change (E.g docs only update)
[x] Covered by existing mbed-os tests (Greentea or Unittest)
[x] Tests / results supplied as part of this PR

Verification:

• Unit tests compile and pass, with no missing tests
• mbed-os-example-cellular compiles

---

Reviewers

@ARMmbed/mbed-os-core @bulislaw @0xc0170 @ARMmbed/mbed-os-connectivity

---

[LDong-Arm]

Travis is almost always an issue when we move something...

[ciarmcom]

@LDong-Arm, thank you for your changes.
@bulislaw @0xc0170 @maclobdell @ARMmbed/mbed-os-ipcore @ARMmbed/mbed-os-wan @ARMmbed/mbed-os-maintainers please review.

[LDong-Arm]

From travis-ci/events:

The command "rm -r rtos/source/TARGET_CORTEX drivers/source/usb connectivity/cellular features/netsocket features/nanostack \
  features/lwipstack features/frameworks/greentea-client \
  features/frameworks/utest features/frameworks/unity components BUILD
" exited with 0.
1.02s$ python tools/make.py -t GCC_ARM -m NUCLEO_F412ZG --source=. --build=BUILD/NUCLEO_F412ZG/GCC_ARM -j0
[Warning] @,: Compiler version mismatch: Have 6.3.1; expected version >= 9.0.0 and < 10.0.0
Building project mbed-os (NUCLEO_F412ZG, GCC_ARM)
Scan: mbed-os
Compile [  0.2%]: mbed_tz_context.c
Compile [  0.4%]: ALT1250_PPP.cpp
[Fatal Error] ALT1250_PPP.h@30,31: AT_CellularDevice.h: No such file or directory

@0xc0170 Why does it remove those directories? The missing file is in connectivity/cellular which it deletes.

[LDong-Arm]

@0xc0170 Why does it remove those directories? The missing file is in connectivity/cellular which it deletes.

Okay, that's no-RTOS build test that excludes RTOS-dependent components. I've added a commit to exclude cellular drivers too as they depend on the cellular stack.

[mergify]

This PR cannot be merged due to conflicts. Please rebase to resolve them.

[evedon]

Looks good.

[mergify]

This PR cannot be merged due to conflicts. Please rebase to resolve them.

Pull request has been modified.

[LDong-Arm]

Rebased. @evedon Could you please re-approve? Thanks

[mergify]

This PR cannot be merged due to conflicts. Please rebase to resolve them.

[0xc0170]

Looks good.

Should be sufficient if this was just rebased. I am reviewing now

[LDong-Arm]

Oh wait, can we drop the "framework/" from the structure (see PR description)? It looks quite redundant as we don't have headers or sources that are not in framework. @0xc0170 @evedon

[evedon]

Oh wait, can we drop the "framework/" from the structure (see PR description)? It looks quite redundant as we don't have headers or sources that are not in framework. @0xc0170 @evedon

We could do that in the future. I'd rather keep most of the existing connectivity structure for now.

[LDong-Arm]

Hi @0xc0170, are you happy to run CI and merge it?

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 6 of 6 test jobs passed
Build number : 1
Build artifacts

[0xc0170]

As approved already, I'll merge now