> I have very little knowledge on how to create ramdisk. I don;t know much > about rootdisk mean. Also, which one of these two is loaded first, when > booting up a network system/device etc. I'm not sure what rootdisk means, but i guess it's the disk (hard-disk/flash etc) where your root directory lives. ramdisk on the other hand is a filesystem image that can be loaded on to the RAM. It emulates a block device in RAM and uses it as a backing store for a regular FS. The regular FS's support must be built into the kernel. ramdisk is loaded first. > > what are the contents goes to ramdisk & rootdisk?. Basically. I am looking ramdisk image basically contains driver modules and other essential utilities which help the kernel load your actual root FS (aka rootdisk). Eg: if your root FS is on a SATA drive, then the kernel would need the SATA driver for talking to the drive. It would also need the relevant FS module (ext/ext3 etc) for reading/writing to the FS image on the SATA drive. These modules will packaged as part of your ramdisk image. I "think", initramdisk/initrd images have been superseded by the more popular initramfs nowadays (not completely sure though). "initramfs" does not require any FS support in the kernel. It is much simpler than a "ram disk" image since it does not have to deal with writing to backing store (which the ram disk was emulating), managing buffers etc. Rather its not a FS at all, but a CPIO archive which is unpacked by the kernel in ram and then accessed w/o the need of a FS. You can read more here: http://www.mjmwired.net/kernel/Documentation/filesystems/ramfs-rootfs-initramfs.txt > for more information how to start a devices with these two. > Is it possible to boot a device with ramdisk alone? Yes its possible, provided your ramdisk has the relevant bits. Eg a lot of embedded systems boot a ramdisk image with busybox in it. HTH, -mandeep > > Thanks in advance. > > Regards, > SS. > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
