where is rootfs lodge at?

[freyone]

there is sda1 device.when i installed tinycore,
i use "df" cmd ,see that rootfs mount on "/"   and dev/sda1 mount on "/mnt/sda1".
does that mean rootfs is on ram because i cannot find those files on /mnt/sda1 such as /lib/libm.so.6 only on rootfs.
why i raise this question?i find other linux distro will make rootfs mounted on real hard disk.and realese the rootfs from ram.

[Juanito]

One of the main features of tinycore is that it boots to ram