hi~ Thank you for your help.
but, i solved my problem myself.
u-boot printenv & linux fw_printenv default value is different.
- Linux fw_printenv(ex. bootdelay=2) is downloaded binary for url.
- U-boot printenv is compiled with my configuration(ex. bootdelay=10).
So, default value is different.
And i tried to compile u-boot/tools/env/ directory, then fw_printenv that compiled has same default env as u-boot printenv tool.