Hi,
I assume that you are using gcc?
then this is about the RAM/ROM usage:
- Code Size Information with gcc for ARM/Kinetis
- text, data and bss: Code and Data Size Explained
If you want to find out how much the CPU is used, that might depend on what you are running on the target.
If you are using an RTOS like FreeRTOS, then you have built-in profiling and performance information you can get:
- Tracing with FreeRTOS+Trace from Percepi
Precepio provides a free version of this tool. FreeRTOS has built in performance analysis (but only per task).
Otherwise you need to collect trace or performance data, e.g. with a TraceLink (First Steps with the P&E Tracelink)
I hope this helps.