Unless you are using the classic Mohor debug interface, you should now use the upstream version of OpenOCD
openOCD including OpenRISC support with Mohor debug interface and Nathan Yawn adv_dbg_if debug interface.
A JTAG driver acting as a client for a VPI JTAG server interface is also included.
+--------------- +----------------+ +----------------+ +------------------+ +----------+
+ + + + + + + + + +
+ OpenOCD core + --> + JAG VIP driver + <==> + JAG VIP server + <--> + JTAG VPI verilog + <--> + JTAG TAP +
+ + + + + + + + + +
+--------------- +----------------+ +----------------+ +------------------+ +----------+
jtag_vpi.c jtag_vpi.c jtag_vpi.v any tap...
--------------------------------------- TCP ------------------ VPI --------------------------------------
--------------------------------------- --------------------------------------------------------------
OpenOCD VPI + Verilog RTL
If you want to use the VPI JTAG driver, you need to configure OpenOCD like this:
./configure --enable-jtag_vpi --enable-adv_debug_sys --enable-maintainer-mode
Then you can start OpenOCD:
./src/openocd -f jtag_vpi.tcl
The JTAG VPI server (on the simulation side) has to be started before OpenOCD.