[dm-devel] Device mapping without using initramfs

[Mikulas Patocka]

On Sun, 21 Jul 2013, ebelcrom ebelcrom wrote:

> Hello folks,
> 
> I played around with dm-crypt without using initramfs for en-/decryption of
> my root file system. The rootfs is encrypted plain with cryptsetup and the
> key is stored at the disk containing the rootfs between MBR and the
> partition. The kernel parameter given to it from the bootloader is
> configured as it should be (cryptdevice, cryptkey, root mapper). The disk
> driver (loaded before) is built-in as well as dm-crypt (loaded after). AES
> support als ist built in as well as a 5 second root wait delay. The message
> I got at boot time is this (cr_rootfs is the encrypted rootfs):
> 
> VFS: Cannot open root device "mapper/cr_rootfs" or unknown-block(0,0)
> 
> According to some hints in the web there is no need to have an initramfs. Is
> that true? Is dm possible without initramfs? If yes what are the steps to
> get there and what should I keep into account?
> 
> Any suggestions are welcome!

Hi

There is no way to activate dm-crypt on startup without initramfs. 
"cryptdevice" and "cryptkey" are parameters for initramfs code, not 
kernel.

Mikulas