After days of hacking, i finally found out there is a dummy driver in openocd. just ./configure –enable-dummy and run it by ./bin/openocd -c ‘interface dummy’ -c ‘adapter_khz 1’ , you can see the dummy driver is running and in the function “static int dummy_write(int tck, int tms, int tdi)”, we can manually toggle the jtag pins

2022/02/13 by admin