define rootfs_align
$(patsubst %-256k,0x40000,$(patsubst %-128k,0x20000,$(patsubst %-64k,0x10000,$(patsubst squashfs%,0x4,$(patsubst root.%,%,$(1))))))
define rootfs_align
$(patsubst %-256k,0x40000,$(patsubst %-128k,0x20000,$(patsubst %-64k,0x10000,$(patsubst squashfs%,0x4,$(patsubst root.%,%,$(1))))))