under the build directory, a number of new files will be written with
prefixes like flash_dbg_* and dbg_*. These can be used to debug using
jtag. the flash_dbg* files will flash the binaries to the dbg target
and, if necessary, set the offset for debugging (e.g. when running
squeezelite, the debugger needs to know that it's running in an offset
that's not the same as recovery). These files can be used in a command
like : xtensa-esp32-elf-gdb.exe --command=build/flash_dbg_squeezelite
