Many thanks to JPMontero_Intel and AlexT_Intel. I didn't settle this problem and now meet a new problem which stop me building any images.
One day ago, I want to put aside trying building flash image for a while, and try to reconfig the kernel to support UVC and Gspca. Before this try, I did successfully build image-spi and image-full and can start up by SD card.
These are my step:
1. follow the yocto dev-manual document, I went to meta-clanton_v1.0.0/yocto_build/tmp/work/clanton-poky-linux-uclibc/linux-yocto-clanton/3.8-r0/linux-clanton-standard-build and make menuconfig and do some selections
2. in yocto_build dir, run bitbake image-full-galileo, and I see successful message but I think my modification doesn't affect.
3. so I run bitbake linux-yocto-clanton -c menuconfig
and select some supports...and save
4. bitbake image-full-galileo (or bitbake image-full)
error shows: /meta-clanton_v1.0.0/yocto_build/tmp/work/clanton-poky-linux-uclibc/linux-yocto-clanton/3.8-r0/linux is not clean, please run 'make mrproper'.
5. so I bitbake linux-yocto-clanton -c devshell and make mrproper
6. then run bitbake image-full-galileo, but report error that .config file was not found!
and I found that every time I make mrproper, the .config file in meta-clanton_v1.0.0/yocto_build/tmp/work/clanton-poky-linux-uclibc/linux-yocto-clanton/3.8-r0/linux-clanton-standard-build was removed.
7. so it seems a dead loop, I didn't know how to process.
wait your advises, thank you!