1# Hafnium RAM disk 2 3Hafnium expects to find the following files in the root directory of its RAM 4disk: 5 6* `manifest.dtb` -- configuration file in DeviceTree format (required) 7* kernels for the VMs, whose names are described in the manifest (optional) 8* initrd of the primary VM, whose name is described in the manifest (optional) 9 10Follow the [preparing Linux](PreparingLinux.md) instructions to produce 11`vmlinuz` and `initrd.img` for a basic Linux primary VM. 12 13## Create a RAM disk for Hafnium 14 15Assuming that a subdirectory called `initrd` contains the files listed in the 16previous section, we can build `initrd.img` with the following command: 17 18```shell 19cd initrd; find . | cpio -o > ../initrd.img; cd - 20``` 21