[uClinux-dev] finding the root device

Lennart Sorensen lsorense at csclub.uwaterloo.ca
Fri Sep 21 10:33:04 EDT 2012

On Fri, Sep 21, 2012 at 04:18:02PM +1000, Greg Ungerer wrote:
> I haven't used uboot on ColdFire, so I am not sure if there is a
> standard way to pass kernel parameters.

We added it and use it.  I believe all needed patches went upstream.
If something is missing we will resend them.

> But you can always build command line options into your kernel config.
> Look in the "Kernel Hacking" -> "Compiled-in Kernel Boot Parameter".
> I always do this with stock kernels, setting the command line to
> "root=/dev/mtdblock0" in the config.

This commit should have taken care of the kernel side:

commit 588baeac38829304390b690142376d2c71ac5c9f
Author: Lennart Sorensen <lsorense at csclub.uwaterloo.ca>
Date:   Fri Sep 18 13:49:36 2009 -0400

    m68knommu: add uboot commandline argument passing support
    This patch adds m68knommu support for getting the kernel command line
    arguments from uboot, including the passing of an initrd image from uboot.
    We use this on a 5270/5271 based board, and have used it on the 5271evb
    development board.  It is based on a patch found in the linux-2.6-denx
    git tree, although that tree seems to have had lots of other changes
    since which are not in the main Linus kernel.  I believe this will work
    on all coldfires, although other m68knommu might be missing the _init_sp
    stuff in head.S as far as I can tell.  I only have the coldfire to
    test on.
    Signed-off-by: Lennart Sorensen <lsorense at csclub.uwaterloo.ca>
    Signed-off-by: Greg Ungerer <gerg at uclinux.org>

I hope the u-boot side got sent upstream.  I should ask the guy that
works on that.  It looks to me as if the u-boot git tree has support
for m68k kernel arguments.  So as long as you use something not too old
it should work.

Len Sorensen

More information about the uClinux-dev mailing list