LAUNCHXL2-TMS57012: connect and debug with openocd

Hi
 i would like connect and debug a launchxl2-TMS57012 with openocd(without specific ide).
I use a small script to launch openocd with these config files
source [find interface/cmsis-dap.cfg]
source [find target/ti_tms570.cfg]
But i have error messages

openocd: aucun processus trouvé
Open On-Chip Debugger 0.9.0 (2018-01-21-13:43)
Licensed under GNU GPL v2
For bug reports, read
    openocd.org/.../bugs.html
Info : only one transport option; autoselect 'swd'
adapter speed: 1500 kHz
/usr/share/openocd/scripts/target/ti_tms570.cfg:23: Error: can't read "_DAP_TAPID": no such variable
in procedure 'script'
at file "embedded:startup.tcl", line 60
at file "openocd.cfg", line 14
at file "/usr/share/openocd/scripts/target/ti_tms570.cfg", line 23
I try with other conf files with similar results.
somebodies can help me?
thanks
alain