(Yes, I have tried CMake, and it is entirely the wrong kind of cross-platform.)
Surely not. Now, this may have been much more trouble than it was worth, but I very nearly guarantee there was a way to do it from a command line.
It's been a while since I Eclipsed, but I (probably erroneously) recall a "generate Makefile" option on most adaptations of it.
However --- good news! I've just found references from 2012 to a thing called MakePackage.jar, which seems to do exactly what we wanted. There certainly wasn't any such thing while I was working on it, so it looks like they changed their mind later. Which would be great, but we'd abandoned the platform by then.
Here's what seems to be left of the Bada documentation.
http://static.bada.com/contents/tutorials/bada_SDK_1.0.0/bad...
Eclipse + Embedded => Cancer
(It was actually not bad; apps written in C++ with a Java-like class library which all ran inside a single process, targeted at fairly small devices. Our test hardware was this massive plastic brick with daughterboards poking out in all directions all wrapped round this utterly gorgeous curved OLED screen.)
You developed on it using a custom IDE which totally wasn't Eclipse (despite being Eclipse) which used gcc as the backend compiler and a bunch of custom tools to generate the deployment packages. Naturally, we ignored the IDE and just used makefiles, so that we could integrate the Bada build into our existing build automation.
...then one update they removed the custom tools and moved their functionality into Eclipse.
This meant that the only way to create applications was to open Eclipse, load the project, and then manually press the 'build' button.
Naturally, we complained, along with everyone else who used it, and never got an answer. The platform died soon after.