[U-Boot] [U-boot] "-mno-unaligned-access" question

Hi, experts:

I have a question about compiler option "-mno-unaligned-access".

Why not open "-mno-unaligned-access" compiler option globally by default when compiling u-boot?

It seems if one driver needs to open it, should set it in Makefile individually:

$(obj) tst/tst.o: CFLAGS += $(PLATFORM_NO_UNALIGNED)

Best wishes,