Previously the drivers unit tests depended on `mbed-headers`, which
is a collection of all available headers in mbed-os. To make it easier
to separate the library, only depend on the headers we're using.
We potentially save flash space by not enabling Mbed TLS self-tests
by default. A new test config file, TESTS/configs/mbedtls.json, is
provided to enable self tests. This newly created JSON file also
enables timing in Mbed TLS so timing gets tested.
This allows us to verify the support for Mbed TLS timing on Mbed OS.
Note: The macros MBEDTLS_TIMING_C and MBEDTLS_TIMING_ALT are not
enabled by default and need to be additionally enabled to run this
test.
Do not compile the Mbed implementation of Mbed TLS unless
MBEDTLS_TIMING_ALT is defined. This prevents a macro check error on
devices that do not have LPTICKER or USTICKER when Mbed TLS timing
is not enabled.
When MBEDTLS_TIMING_C and MBEDTLS_TIMING_ALT are enabled,
the Arm Compiler generates errors like the following (one for
each missing symbol):
Error: L6218E: Undefined symbol mbedtls_timing_get_delay
Reason:
The function `mbedtls_timing_self_test()` in the Mbed TLS default
`timing.c` always gets compiled, if MBEDTLS_SELF_TEST is defined.
And MBEDTLS_SELF_TEST is always defined, as we have a Greentea test
to run some of the Mbed TLS self tests. (In the future we should try
not to enable MBEDTLS_SELF_TEST except for tests, but it requires
a rework in our test flow.)
`mbedtls_timing_self_test()` tests (calls) the full API declared in
`timing.h`, and the ARM Compiler requires all symbols referenced by
all functions to be defined, even those not used by the final
application. This is unlike GCC_ARM which resolves what are required.
Solution:
To fix the "undefined symbol" errors, we add an implementation of
`mbedtls_timing_get_timer()` based on Mbed OS `LowPowerTimer` or
`Timer` (depending on which one is available), and copy Mbed TLS's
default `mbedtls_timing_set_delay()` and `mbedtls_timing_get_delay()`
which are built on top of `mbedtls_timing_get_timer()`. This will also
benefit user applications that need to enable timing in Mbed TLS.
Previously we used `gettimeofday()` for Mbed TLS timing, but its
implementation provided by Mbed OS is only precise to seconds. The
microsecond component of the output `struct timeval` is always set
to zero. But Mbed TLS requires millisecond precision.
To provide required timing precision, switch to use `LowPowerTicker`
or (microsecond) `Ticker`. `LowPowerTicker` is preferred as it saves
power and Mbed TLS does not require microsecond precision.
Adding mbed-os subdirectories that are not required for a specific project to .mbedignore is a good way to reduce compilation time. Sometimes it happens that tests depend on ignored files, which causes the test-build to fail even though the corresponding feature/component
is not configured. The reason is that the conditional that skips the test is placed after the includes.
Block-Wise request (block1) error handling improvements:
* Removed SN_COAP_BLOCKWISE_MAX_TIME_DATA_STORED usage. Block-Wise requests will now follow normal retranmission rules.
* Process block1 responses only once. If response is coming in wrong order just ignore it wait next response to happen.
Typically when adding a unit test directory to a CMake project a check
will be used to ensure the subdirectory is added only if the following
are true:
* The BUILD_TESTING option is set to ON.
* The current CMake project is the top-level project.
The reason being, if a downstream project includes our project they
generally don't want to build our unit tests.
In mbed-os, we do correctly specify the above condition before adding
the central UNITTEST subdirectory, which fetches googletest and adds the
"stub" libraries the unit tests depend on. However, we only check if
CMAKE_CROSSCOMPILING is OFF (or undefined) before actually adding the
unit tests. This mismatched logic would lead to unexpected build
failures in various scenarios. One likely case could be: a downstream
project including mbed-os happens to set CMAKE_CROSSCOMPILING to
OFF/undefined for any reason (possibly to build its own unit tests).
mbed-os would go ahead and attempt to build its tests without fetching
googletest or adding the required stub targets.
To fix the issue replace the check for CMAKE_CROSSCOMPILING in the unit
tests with the same BUILD_TESTING idiom we use for adding the central
UNITTESTS subdirectory.
googletest now follows the "Abseil Live at HEAD" philosophy, which means
they recommend using the latest commit on the master branch and always
compiling from source. They recommend this to avoid version mismatch
issues and "diamond dependency" problems which are common in dependency
graphs with pinned versions. Google make the "promise" that future
changes won't break downstream code if it follows the "Abseil
compatability guidelines".
Upping the version to master also fixes some CMake configure time
warnings that were present with the older tagged releases of googletest:
CMake Deprecation Warning at __build/_deps/googletest-src/CMakeLists.txt:4 (cmake_minimum_required):
Compatibility with CMake < 2.8.12 will be removed from a future version of
CMake.
Update the VERSION argument <min> value or use a ...<max> suffix to tell
CMake that the project does not need compatibility with older versions.
CMake Deprecation Warning at __build/_deps/googletest-src/googlemock/CMakeLists.txt:45 (cmake_minimum_required):
Compatibility with CMake < 2.8.12 will be removed from a future version of
CMake.
Update the VERSION argument <min> value or use a ...<max> suffix to tell
CMake that the project does not need compatibility with older versions.
CMake Deprecation Warning at __build/_deps/googletest-src/googletest/CMakeLists.txt:56 (cmake_minimum_required):
Compatibility with CMake < 2.8.12 will be removed from a future version of
CMake.
Update the VERSION argument <min> value or use a ...<max> suffix to tell
CMake that the project does not need compatibility with older versions.
We get a linker warning with the recently added timing module
implementation for Mbed. This is because there is Mbed TLS also ships a
file called timing.c, which we are including in Mbed OS also. With CLI
1, we get an error about unique object files because of the similarly
named implementation files.
Object file timing.o is not unique! It could be made from: mbed-os/connectivity/mbedtls/source/timing.c mbed-os/connectivity/mbedtls/platform/src/timing.cpp
Rename the Mbed timing module implementation to timing_mbed.cpp to avoid
this naming conflict.
Fixes: b8781e527b ("mbedtls: Add an alt implementation of timing")
Fixes#14759
Martin Kojtal
Rajkumar Kanagaraj
mbedmain
Paul Szczepanek
saheerb
Lingkai Dong
Sebastian Stockhammer
Antti Yli-Tokola
Paul Szczepanek
AlbanJeantheau-silabs
Alban Jeantheau
Robert Walton
Jaeden Amero