[U-Boot] Checking validity of rootfs in NAND-Flash

Hello everybody,

in my project, u-boot (2009.11) loads a large jffs2-rootfs image (80 MB, with an attached crc32-checksum) from SD-card into a NAND-Flash. To ensure the validity of the rootfs, i let u-boot then clear the RAM-part, read back the rootfs from NAND into RAM, do a crc32 checksum over it and compare this checksum with the crc32- checksum that was attached to the image. This validity check takes about 70 seconds. Do you know a faster/better way of checking the validity?

Thanks in advance, Harald Vollmer