Can I access parameters in my protractor configuration file?

I am not completely sure if protractor globals are set at the beforeLaunch() stage, but they are definitely available at onPrepare() step.

Access the params object through the global browser object:

console.log(browser.params.baseUrl);

Update:
Using Jasmine 2.6+, protractor 4.x, browser.params was empty, but the following worked in onPrepare() step:

console.log(browser.baseUrl);