Debugging the ADuCM410 in Eclipse (on Ubuntu 20.04)

I'm doing a project on an ADuCM410 and have the evaluation board and the Midas-Link debugger.

I was able to boot my machine into Windows and run an example program on it using the Keil SDK.

Under Linux, once I figured out to set the J-Link to SWD rather than J-TAG (why did they label the cable as J-TAG?) I was able to talk to in in Ozone, and in Segger Embedded Studio. 

For various reasons, I would rather use the Eclipse IDE, but cannot quite get things to work.  At the moment I can get "Hello World" to compile but am getting linker errors on things like `_sbrk', `_write', `_close' etc.

Has anyone been able to get the M410 working in the Eclipse IDE?  I've tried following the generic "Arm on the Eclipse" instructions.  There might be something that I need to do to make use of the Keil packages supplied by Analog devices.