You attempt to run OpenOCD with a target board and a JTAG interface device, such as the TinCanTools Flyswatter. OpenOCD exits with a config file error like this:
Runtime Error: target/samsung_s3c2410.cfg:26: invalid command name "jtag"
This particular config file target/samsung_s3c2410.cfg is called by hammer.cfg, the config file for the TinCanTools Hammer. You would see this error if you ran OpenOCD from the command line like this:
openocd -f board/hammer.cfg -f interface/flyswatter.cfg
Solution: Reverse the Order of the Config Files
Instead of running OpenOCD as above, pass OpenOCD flyswatter.cfg before hammer.cfg, like this:
openocd -f interface/flyswatter.cfg -f board/hammer.cfg
OpenOCD should now run successfully.