Arch Linux

splicer

Member

Registered: 2009-10-30

Posts: 11

Unable to boot module-free kernel without initramfs

Hi all, I've been using Arch for the last week or so, and it's been fun.. I've been trying to speed up the boot process, so I've compiled a kernel with all the necessary modules (that used to be listed in lsmod). However, when I remove the initrd command from grub, I get a kernel panic - something along the lines of "VFS cannot mount root". But I've definitely built the scsi and sata modules into the kernel, and after a successful boot (with initramfs) lsmod shows nothing, so I don't know what's the problem...

skipio

Member

Registered: 2009-01-27

Posts: 12

Re: Unable to boot module-free kernel without initramfs

hello, if you want to start Linux without initrd you have to build all the required kernel modules for booting the root partition statically (<Y> not <M> in menuconfig). So you will have to add scsi, stata/pata and the file system of your root partition.
if you still have problems please post your /boot/grub/menu.lst
hope that helps.

Last edited by skipio (2009-11-04 09:49:32)

vacant

Member

From: downstairs

Registered: 2004-11-05

Posts: 816

Re: Unable to boot module-free kernel without initramfs

The fractions of a second you save each boot won't ever be recouped against the amount of time you have devoted to building/testing your custom kernel. So you're doing this for a bet right?

skipio

Member

Registered: 2009-01-27

Posts: 12

Re: Unable to boot module-free kernel without initramfs

The fractions of a second you save each boot won't ever be recouped against the amount of time you have devoted to building/testing your custom kernel. So you're doing this for a bet right?

Arch Linux Kernel
Boot time: 17s
89.9 MiB of Ram used with Openbox started

My custom Kernel
Boot time: 15s
79.8 MiB of Ram used with Openbox started

Moreover building a custom kernel is educative and fun.

klixon

Member

From: Nederland

Registered: 2007-01-17

Posts: 525

Re: Unable to boot module-free kernel without initramfs

Did you also build in root's filesystem?

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Stand back, intruder, or i'll blast you out of space! I am Klixon and I don't want any dealings with you human lifeforms. I'm a cyborg!

bender02

Member

From: UK

Registered: 2007-02-04

Posts: 1,328

Re: Unable to boot module-free kernel without initramfs

Also you can't use UUIDs or things like this in the grub's kernel line for root=. You need to use the good ol' /dev/sda1 or such.

gen1s

Member

From: Russian Federation

Registered: 2009-08-04

Posts: 17

Re: Unable to boot module-free kernel without initramfs

I've recently builded initrdless kernel on my laptop. My root partition on EXT4, SATA disk.
My changes in config:
Block devices -> RAM block device support (disable)
ATA/ATAPI/MFM/RLL support (disable whole branch)
SCSI device support ->
  SCSI target support (Y)
  SCSI disk support (Y)
  SCSI tape support (Y)
  SCSI CDROM support (Y)
  SCSI generic support  (Y)
  ->Serial ATA (prod) and Parallel ATA (experimental) drivers ->
    ATA ACPI Support (Y)
    SATA Port Multiplier support (Y)
    AHCI SATA support (Y)
    ->ATA SFF support->
      Intel ESB, ICH, PIIX3, PIIX4 PATA/SATA support (Y)
      Generic ATA support (Y)
File systems ->
  The Extended 4 (ext4) filesystem (Y)

After that i can boot without initrd line in GRUB. It is a liitle bit faster. But i don't know how to resume with TuxOnice so i switched back to initrd.

Here is my config (kernel26-zen, x86_64): http://dl.getdropbox.com/u/1147064/conf … ess.x86_64

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: Unable to boot module-free kernel without initramfs

Check what modules are still provided by the intiramfs image generated for the new kernel.

splicer

Member

Registered: 2009-10-30

Posts: 11

Re: Unable to boot module-free kernel without initramfs

ah bender02 was spot on - changing it to /dev/sdaX worked for me. Why is initramfs necessary for using UUIDs, though?

I'm aware that the time saved at boot probably won't offset the time spent optimizing it, but it's been educational ^^

Last edited by splicer (2009-11-04 17:56:28)

klixon

Member

From: Nederland

Registered: 2007-01-17

Posts: 525

Re: Unable to boot module-free kernel without initramfs

udev

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Stand back, intruder, or i'll blast you out of space! I am Klixon and I don't want any dealings with you human lifeforms. I'm a cyborg!