Hi hayaoki7,
Indeed, all the Model-Based Design Toolboxes from NXP are now cost free. You can use it for free with no fee charge.
The entire suite & ecosystem (IDE for debugging, GCC toolchain, bootloaders) is provided for free - all you need to do is to have an NXP account to download the licences - also free of charge.
You need to have a Matlab environment with Embedded Coder toolbox in order to be able to generate the C code automatically. That is a cost you have to consider but from our point of view we assume you have already such environment.
Hope this helps!
Daniel
