I think I know how to make the bootable CF re-usable now. On the CF, in /var, remove a symbolic link "registry", and then the CF will be always bootable. The theory behind the veil is still unknown to me.
(Wrong info. Ignore the above. The right answer is provided down below.)
So, the steps to create a bootable CF should be:
1. Make a ext2 partition on a CF of 128 MB or above.
2. Mount the CF on iLiad. The command should look like "mount -t ext2 /dev/hda1 /mnt/cf".
3. Copy everything on iLiad rootfs to /mnt/cf.
4. Create a directory "/mnt/cf/mnt/settings" and copy everything under "/mnt/settings" to that directory.
4. Edit /mnt/cf/etc/fstab and remark the line with /dev/tffsa1 (the iLiad rootfs), /dev/tffsa7 (/mnt/settings) and /dev/hda1 (the CF).
5. Delete a symbolic link "registry" under /mnt/cf/var.
(Not necessary. Ignore this step)
6. Create a dummy directory (by copying a sibling directory) under "/mnt/cf/usr/share/contentlister/mode/en" so that you can differentiate whether iLiad boots from CF.
7. echo "boot" > /mnt/cf/config.txt
Now, iLiad developers can do more experiements on the device without touching the rootfs on iLiad.
Note
(very important):
Some unknown program will create a "logfile.txt" in /. If iLiad got turned off without calling proper routines, it will cause "logfile.txt" not closed correctly and damage the filesystem on the bootable CF, which makes the bootable CF NOT re-usable. To avoid this problem, iLiad must be turned off by pushing the turn-off button.
This is only the case for bootable CF. It won't affect normal iLiad rootfs.
