Water System User Manual

Restoring the NAND Flash
Additional Procedures A-13
A.6.2 Restoring the NAND Flash Using NFS
Once you have loaded the kernel binary to the corresponding NAND
partition as described in Section A.6.1, you can use NFS to populate the
YAFFS2 image (dm357_flash_image_#_#_#_#.tar) to the NAND
partition. The YAFFS2 image should reside on the NFS Server root
directory. Follow these steps:
1) Copy the dm357_flash_image_#_#_#_#.tar file from the DVSDK disk
to the NFS mounted root directory. For example,
/home/<useracct>/workdir/filesys.
2) Set the bootcmd environment variable to boot to kernel and mount to
NFS. (Alternatively use the 'dhcp' command for the EVM IP
Address.)
EVM # setenv bootcmd 'nboot 0x80700000 0 0x400000; bootm'
EVM # setenv bootargs console=ttyS0,115200n8 noinitrd
ip=dhcp root=/dev/nfs rw nfsroot=<nfs_host_ip>:<nfs_root_path> mem=232M
video=davincifb:vid0=0,2025K:vid1=0,1350K:osd0=720x576x16,
2025K davinci_enc_mgr.ch0_output=COMPOSITE
davinci_enc_mgr.ch0_mode=ntsc
Note: These variables need not be saved, because NFS is just a
temporary filesystem.
3) Execute the 'boot' command to boot the Linux kernel.
4) Login to the EVM as root and execute the following set of U-Boot
commands to mount the NAND partition and populate the YAFFS2
image:
EVM # mkdir /mnt/nand
EVM # flash_eraseall /dev/mtd0
EVM # mount -t yaffs2 /dev/mtdblock0 /mnt/nand/
EVM # cd /mnt/nand
EVM # tar xf /dm357_flash_image_#_#_#_#.tar
EVM # cd
EVM # umount /mnt/nand
EVM # reboot
5) When the EVM comes up after rebooting from the previous steps,
press Esc to get back to U-Boot prompt. You can now restore the out-
of-the-box U-Boot environment variables as described in Section
A.4.1.