Add a -u flag for U-Boot SPL which requests that unit tests be run. To
make this work, export dm_test_main() and update it to skip test features
that are not used with of-platdata.
To run the tests:
$ spl/u-boot-spl -u
U-Boot SPL 2020.10-rc5 (Oct 01 2020 - 07:35:39 -0600)
Running 0 driver model tests
Failures: 0
At present there are no SPL unit tests.
Note that there is one wrinkle with these tests. SPL has limited memory
available for allocation. Also malloc_simple does not free memory
(free() is a nop) and running tests repeatedly causes driver-model to
reinit multiple times and allocate memory. Therefore it is not possible
to run more than a few tests at a time. One solution is to increase the
amount of malloc space in sandbox_spl. This is not a problem for pytest,
since it runs each test individually, so for now this is left as is.
Signed-off-by: Simon Glass <sjg@chromium.org>
b25ff5cbaa