How to perform flash all partition except system.img

I’m trying to tune the pinmux with our custom board. But I found if I want to upgrade pinmux, I need to reflash all of the partitions including system.img by flash.sh tool.
That make me 10 minutes every time even if I only have a tiny modification. Is there any way to perform flash all partitions except system.img ?

hello chester.tseng,

here’s one tips,
according to Flash Script Usage, you may include -r options to reuse the existing system.img to save your time.
thanks