initrd / initramfs - root*,ro,rw parameters

syrius.ml_at_no-log.org
Date: 01/27/05

  • Next message: Olaf Hering: "[PATCH] use misc dynamic minor for sonypi driver" 
    To: linux-kernel@vger.kernel.org
Date:	Thu, 27 Jan 2005 14:33:43 +0100

    Hi,

    It seems a lot of initrd images expect to find the final root
    filesystem device in the root= boot parameter while
    Documentation/initrd.txt states root should be set to /dev/ram0.
    I'm not sure, but it seems this patch introduced in 2.6.11-rc1
    <bunk@stusta.de>
      [PATCH] init/initramfs.c: make unpack_to_rootfs static
    made root=/dev/ram0 mandatory. And initrd images that expect people to
    set their root boot parameter to the final device don't work anymore.

    It seems logical to me, as Documentation/kernel-parameters states
    ro, rw, root, rootflags, rootdelay and rootfstype are kernel start-up
    parameters. And in the case of using a loaded-into-dev-ram0 initrd
    those parameters apply to /dev/ram0.
    It's the initrd's job to define new parameters it will use to mount
    the final root filesystem with. (for ex: pivot_root=, pivot_root_rw,
    pivot_root_ro, pivot_root_flags, pivot_root_fstype and possibly
    pivot_root_delay)

    (for sure i'm not considering the old deprecated root_change method
    nor devfs)

    Is it correct ?

    I'd like to hear maintainers' opinions about it.

    From Documentation/initrd.txt:
    <quote>
    Finally, you have to boot the kernel and load initrd. Almost all Linux
    boot loaders support initrd. Since the boot process is still compatible
    with an older mechanism, the following boot command line parameters
    have to be given:

      root=/dev/ram0 init=/linuxrc rw
    </quote>

    How should this be read ? I guess it has to be updated so that it's
    now mandatory to use root=/dev/ram0. Isn't it ?

    I might be totally wrong.
    At least i'm pretty sure some clarifications will help.

    TIA. 

    -- 
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
  • Next message: Olaf Hering: "[PATCH] use misc dynamic minor for sonypi driver"

    Relevant Pages

    • [PATCH] documentation: Documentation/initrd.txt
      ... the boot loader loads the kernel and the initial RAM disk ... frees the memory used by initrd ... initrd is mounted read-write as root ... linuxrc places the root file system at the root directory using the ...
      (Linux-Kernel)
    • Re: booting from ISO image on HD?
      ... I'm not going to write the pivot root script, ... > through customized initrd files for each one. ... I have to insmod the loop kernel module(e.g. ... The idea is that either you build what you need to boot into your ...
      (comp.os.linux.misc)
    • Re: (re-)boot woes
      ... > This looks like an initrd problem. ... As in that the kernel needs an ... But these appear not to be getting loaded and so the root ... There are also other boot manager that are reported to 'find' the ...
      (Debian-User)
    • Re: [opensuse] LILO/Grub Problem
      ... to show up and boot. ... (But also produced the kernel initrd ... Are you saying the above (hoping the wrapping is the email programs and ... next 3 indented, starting with root, then kernel, then initrd. ...
      (SuSE)
    • RE: Linux hacked
      ... Subject: Linux hacked ... After you boot up into the OS running from CD, ... >> First let me say I'm a security novice. ... >> been unsuccessful in getting root back. ...
      (Security-Basics)