RAM overflow problem during the generation of twister Code Coverage rapport

[marwaiehm-st]

I'm using the twister code coverage to generate the code rapport " west twister --coverage" , the problem is that it works only with samples/hello_world test . On the other tests i didn't have an error but it always mentioned as skipped " 0 of 1 test configurations passed (0.00%), 0 failed, 0 errored, 1 skipped with 0 warning" so it will generate the index.htlml but with 0% coverage.

• Example:

The test passed without adding coverage:

west twister --device-testing --device-serial /dev/ttyACM0 --device-serial-baud 115200 -p nucleo_f401re -T  tests/kernel/timer/timer_behavior

Result
```shell
"name":"tests/kernel/timer/timer_behavior/kernel.timer.timer",
            "arch":"arm",
            "platform":"nucleo_f401re",
            "path":"tests/kernel/timer/timer_behavior",
            "run_id":"660a10c2ddd1f73074988a324fc11ac3",
            "runnable":true,
            "retries":0,
            "status":"passed",
            "execution_time":"182.18",
            "build_time":"8.90",

When i launch the test with adding the coverage support, the test will be skipped

west twister --coverage --device-testing --device-serial /dev/ttyACM0 --device-serial-baud 115200 -p nucleo_f401re -T  tests/kernel/timer/timer_behavior

Result

INFO    - JOBS: 8
INFO    - Adding tasks to the queue...
INFO    - Added initial list of jobs to queue

INFO    - 1 test scenarios (1 test instances) selected, 1 configurations skipped (1 by static filter, 0 at runtime).
INFO    - 0 of 1 test configurations passed (0.00%), 0 failed, 0 errored, 1 skipped with 0 warnings in 3.25 seconds
INFO    - In total 0 test cases were executed, 1 skipped on 1 out of total 714 platforms (0.14%)
INFO    - 0 test configurations executed on platforms, 0 test configurations were only built.

RAM overflow is the reason that was mentioned on the twister.json file

"name":"tests/kernel/timer/timer_behavior/kernel.timer.timer",
            "arch":"arm",
            "platform":"nucleo_f401re",
            "path":"tests/kernel/timer/timer_behavior",
            "run_id":"e4343b565828f190dfdfe90592b5fe1e",
            "runnable":true,
            "retries":0,
            "status":"skipped",
            "reason":"RAM overflow",
            "execution_time":"0.00",
            "build_time":"8.49",

I'm wondering what's the minumum ram size we need to be able to generate code coverage rapport specially for the kernel tests ?