Add a test of DFU functionality to the Python test suite. The test
starts DFU in U-Boot, waits for USB device enumeration on the host,
executes dfu-util multiple times to test various transfer sizes, many
of which trigger USB driver edge cases, and finally aborts the DFU
command in U-Boot.

This test mirrors the functionality previously available via the shell
scripts in test/dfu, and hence those are removed too.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>

dfu-util allows filtering on USB device vendor:product ID by using
the -d flag (-d 0451:d022).
Such option is very handy when many DFU devices are connected to a single
host PC. This commit allows testing when above situation emerges.

Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Simon Glass <sjg@chromium.org>

Tested-by: Lukasz Majewski <l.majewski@majess.pl>
Test HW - AM335x Beagle Bone Black
NOTE: Max size of file to transfer: 2MiB

By mistake I've forgotten to add the SPDX license tags for the DFU testing
scripts.
This commit fixes that and also provides some other relevant information.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Stephen Warren <swarren@nvidia.com>

It is now possible to pass to the dfu_gadget_test_init.sh script the sizes
of files to be generated.

This feature is required by UMS tests which reuse this code.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Stephen Warren <swarren@nvidia.com>

On Tegra, the DFU buffer size is 1M. Consequently, the 8M test always
fails. Add tests for the 1M size, and one byte less as a corner case,
so that some large tests are executed and expected to pass.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

Call cleanup() before running tests too. If a previous test was CTRL-C'd
some stale files may have been left around. dfu-util refuses to receive
a file to a filename that already exists, which results in false test
failures if the files aren't cleaned up first.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>

Various misc enhancements to dfu_gadget_test.sh:

* After every write (download), perform a write to a different file
  with different data. This ensures that the DFU buffer's content is
  replaced, so that if the read (upload) succeeds, we know that the
  correct data was actually read from the storage device, rather than
  simply being left over in the DFU buffer. This requires two alt
  setting names to be passed to the script, and a dummy data file to
  be generated by dfu_gadget_test_init.sh.

* Fix the assumption that dfu_gadget_test.sh is run from the directory
  that contains it, by cd'ing to that directory before invoking
  ./dfu_gadget_test_init.sh.

* Use $DIR$RCV_DIR consistently, rather than using plain $RCV_DIR in
  some places.

* Add 959, 961 test file sizes, to be consistent with having one
  more than and one less than all the other "round" sizes 64, 128, and
  4096.

* Remove references to $BKP_DIR from dfu_gadget_test_init.sh, since it
  isn't used.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

This commit adds test scripts for testing if any commit has introduced
regression to the DFU subsystem.

It uses md5 to test if sent and received file is correct.
The test detailed description is available at README file.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>