[U-Boot] Some question about uboot

[loody]

Dear all:
While porting uboot, I find there are too many things I don't need at
all, like net, i2c etc.
How could I remove them from my uboot binary to minimize the size of
uboot, my flash limitation is 6k?
I try to edit Makefile to remove them by marking some library setting,
but it compile error after I doing so.
Is there any easier way to meet my requirement?
Appreciate your help,
miloody