Arch Linux

Malstrond

Member

From: Germany

Registered: 2009-06-03

Posts: 98

[Abandoned] device-mapper/dm-crypt/luks without initramfs

Hi everyone,
i attempted to compile a custom kernel to reduce the my EEE 1000H's boot time by compiling everything i need statically, which seems to work well, except one thing: Accessing my encrypted root partition. I created it by following the wiki and all is well if i boot "normally" (using an initramfs and the encrypt hook).
So i tried to compile the modules necessary to boot encrypted partitions into the kernel. The options i changed to achieve this were

CONFIG_BLK_DEV_DM=y
CONFIG_DM_CRYPT=y
CONFIG_CRYPTO_AES=y
CONFIG_CRYPTO_AES_586=y

in my kernel config (along with all the other stuff of course). All the
The i tried to boot the new kernel via GRUB using just

title Test
root (hd0,0)
kernel /vmlinuz-2.6.30-rc8-eee1000h-kms root=dev/sda3 i915.modeset=1 ro 3

but it panics

sd 0:0:0:0: [sda] Attached SCSI disk
UDF-fs: No partition found (1)
List of all partitions:
0800 156290904 sda driver: sd
  0801 497983    sda1    #the unencrypted /boot
  0802 2000092   sda2    #swap
  0803 153790245 sda3    #root, ext3 fs
No filesystem could mount root, tried: ext3 ext2 iso9660 udf
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,3)

altough it does this in my monitor's native resolution . The kernel seems to try to access the encrypted partition directly and the device mapper doesn't seem to be active.
I guess this is because the script in
/lib/initcpio/hooks/encrypt
seems to handle unlocking the volume and activating the device mapper and it's obviously missing now. I think i would have to rewrite it to not use modules - but this is far beyond my abilites.
I haven't found any further information on this issue either, it just doesn't seem to be possible, or rather, advisable to encrypt your root partition while not using an initramfs. I guess i'll have to use one or just encrypt only my user's home directory, or does anyone have an idea on how to solve this problem?

Update: I gave up on this.

Last edited by Malstrond (2009-08-13 20:20:03)