Excluding Kernel From Gingerbread Source Build


I’m trying to build the Gingerbread root file system from source for a BB-xm-like board of mine. I’m writing a host of build scripts to build all of the various components (MLO, u-boot, kernel, and rootfs). My question is, can I exclude the kernel when building the rootfs? I can make the kernel separate from the rootfs using the -C option, but I don’t see of a way to just make the rootfs without also doing the kernel. Does anybody have any insight into this?