Add user's BUILD: _date_ _time_ to M115 output

[chestwood96]

I added the buld-date and time to the end of the M115 report so I could determine if the firmware actually flashed (SD flash on the skr E3 mini can be flaky sometimes)

Benefits

Ability to tell when the running firmware was built and if a firmware flash succeeded, small quality of live improvement.

[Roxy-3D]

Is there a way to add the Build Directory path to this information?
That would be super helpful for me.

[chestwood96]

Is there a way to add the Build Directory path to this information?
That would be super helpful for me.

I could not find a macro that contains that but that does not have to mean anything. I actually found the __DATE__ variable kinda by accident. If you find a way to get the path at compile time it should be relatively easy to add.

[Roxy-3D]

I don't mess with the makefile stuff very much. But almost for sure, the makefile knows where it is being invoked from. I wonder if we could pipe that information to a text file and some how package it up with the other M115 info?

[randellhodges]

You can use platformio to set define.

https://github.com/randellhodges/Marlin/blob/skr-1.4/buildroot/share/PlatformIO/scripts/common-version.py

I have one that sets the git branch and build date this way. Add it to the platform extra scripts.

Have it set the various extra defines, then in M115 have some ifdefs for the extra output maybe?

[Roxy-3D]

Yes... That would be very helpful. I guess whether it helps a person or not depends on how they do their work. But I have a folder for each printer and copies of the entire build directory for various versions of that printer's firmware (with various configuration changes and new features under construction).

So knowing the actual path to build tree that generated a printer's firmware is very useful when I come back to a printer that hasn't been modified (or maybe used) for a while.