In python 3.x the xrange() function has been removed, and range()
returns an iterator much like Python 2.x's xrange(). Simply use range()
in place of xrange() in order to work on both python 2.x & 3.x. This
will mean a small cost on python 2.x since range() will return a list
there rather than an iterator, but the cost should be negligible.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

In python 3.x print must be called as a function rather than used as a
statement. Update uses of print to the function call syntax in order to
be python 3.x safe.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

When sandbox SPL is enabled we want to start that rather than U-Boot proper,
since some tests may rely on running it first.

Signed-off-by: Simon Glass <sjg@chromium.org>

Normally tests will run with the test.dtb file designed for this purpose.
However, the verified boot tests need to run with their own device-tree
file, containing a public key.

Make the device-tree file a config option so that it can be adjusted by
tests. The default is to keep the current behaviour.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Teddy Reed <teddy.reed@gmail.com>

This shows more output, such as the internal output generated by the unit
test ("ut") command, which makes it easier to debug issues.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Implement command--line option --gdbserver COMM, which does two things:

a) Run the sandbox process under gdbserver, using COMM as gdbserver's
   communication channel.

b) Disables all timeouts, so that if U-Boot is halted under the debugger,
   tests don't fail. If the user gives up in the middle of a debugging
   session, they can simply CTRL-C the test script to abort it.

This allows easy debugging of test failures without having to manually
re-create the failure conditions. Usage is:

Window 1:
./test/py/test.py --bd sandbox --gdbserver localhost:1234

Window 2:
gdb ./build-sandbox/u-boot -ex 'target remote localhost:1234'

When using this option, it likely makes sense to use pytest's -k option
to limit the set of tests that are executed.

Simply running U-Boot directly under gdb (rather than gdbserver) was
also considered. However, this was rejected because:

a) gdb's output would then be processed by the test script, and likely
   confuse it causing false failures.

b) pytest by default hides stdout from tests, which would prevent the
   user from interacting with gdb.

   While gdb can be told to redirect the debugee's stdio to a separate
   PTY, this would appear to leave gdb's stdio directed at the test
   scripts and the debugee's stdio directed elsewhere, which is the
   opposite of the desired effect. Perhaps some complicated PTY muxing
   and process hierarchy could invert this. However, the current scheme
   is simple to implement and use, so it doesn't seem worth complicating
   matters.

c) Using gdbserver allows arbitrary debuggers to be used, even those with
   a GUI. If the test scripts invoked the debugger themselves, they'd have
   to know how to execute arbitary applications. While the user could hide
   this all in a wrapper script, this feels like extra complication.

An interesting future idea might be a --gdb-screen option, which could
spawn both U-Boot and gdb separately, and spawn the screen into a newly
created window under screen. Similar options could be envisaged for
creating a new xterm/... too.

--gdbserver  currently only supports sandbox, and not real hardware.
That's primarily because the test hooks are responsible for all aspects of
hardware control, so there's nothing for the test scripts themselves can
do to enable gdbserver on real hardware. We might consider introducing a
separate --disable-timeouts option to support use of debuggers on real
hardware, and having --gdbserver imply that option.

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

Some unit tests expect the cwd of the sandbox process to be the root
of the source tree. Ensure that requirement is met.

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

This is required for at least "ut dm" to operate correctly.

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