Version/Signature in Flash

Hi,

is there already a defined wy to place a user defined signature in the
flash memory?

Use Case: Simply put some version info, maybe a a string with given
format or a git hash id or whatever in a specified flash area.

I see we have a section ".signature" but this is in use for a predefined
3 byte signature. I also see in the linker scripts that there is
something called "user_signatures" but that seems to be unsupported for
the rest of the linker script. But maybe I looked in the wrong file...

Any suggestions?

Thanks
  Klaus