25 May
2006
25 May
'06
1:45 a.m.
>----------------------------------------------------------------------
>
>Message: 1
>Date: Thu, 25 May 2006 01:02:01 +0900
>From: Joel Roth <joelz(a)pobox.com>
>Subject:
>To: linux-audio-user(a)music.columbia.edu
>Message-ID: <20060524160201.GD7001@sprite>
>Content-Type: text/plain; charset=iso-8859-1
>
>
>
>>On Wed, 24 May 2006 at 11:25 +1200, Hamish Low wrote:
>>
>>
>>>Firstly thanks to Asbjørn, Lee, Tim and others who have given me advice
>>>so far.
>>>
>>>I tried using Asbjørn's vanilla kernel but it didn't work as our
>>>laptops are different, but your config settings were a good guide.
>>>
>>>I downloaded the source package for 2.6.16
>>>I did make oldconfig, to use the config already working on my machine
>>>(just without the VXpocket support), I tried compiling the kernel as per
>>>the instructions on the Demudi page
>>><http://demudi.agnula.org/wiki/Low-latencyKernelBuildingHowto>, and by
>>>referencing Asbjørn's config settings
>>>Lee had written that CONFIG_ISAPNP must be enabled, but this wasn't an
>>>option that I could choose in menuconfig, there was just a hyphen beside
>>>this option, also this wasn't enabled in Asbjørn's settings which
>>>reportedly works.
>>>
>>>but got this error message on reboot
>>>
>>>Kernel panic - not syncing: VFS: Unable to mount root fs on
>>>unknown-block(0,0)
>>>
>>>I assume this means I didn't have the exact settings configured for my
>>>laptop.
>>>
>>>
>
>On Wed, May 24, 2006 at 07:44:59AM -0600, Hans Fugal wrote:
>
>
>>Your problem is that stock kernels usually use an initrd, but when you
>>compile by hand you aren't setting up the initrd. You can either grok
>>initrd, or compile a few more things into the kernel instead of as
>>modules. Needless to say the latter is by far easier.
>>
>>
>
>That is a judgement call.
>
>For the former (under debian, not guaranteed, an example)
>
> apt-get initrd-tools
>
> mkinitrd -o /boot/initrd-img-2.6.16 2.6.16
>
> Add an initrd line to GRUB or LILO
>
>For the latter (ditto, guaranteed not to work)
>
> > You need the appropriate disk drivers (IDE/ATA, for example) and
> the
> > appropriate file system(s) compiled in (ext3 for example).
>
> Here is a start, all the items containing EXT2, EXT3, IDE
> but not VIDEO.
>
> Just change all the 'm' or 'not set' to 'y', append to
> the end of .config, and compile. (Praying doesn't help,
> but it might make you feel better. Pizza and beer are
> also considered highly effective.)
>
> $ grep EXT3 /src/linux-2.6.16/.config
> CONFIG_EXT3_FS=m
> CONFIG_EXT3_FS_XATTR=y
[.config file stuff snipped]
On Thu, May 25, 2006 at 02:39:41PM +1200, Hamish Low wrote:
thanks Joel, but that didn't work, I got the same
error on reboot
I've gone through and deleted all the vanilla kernel directories and
will try to insert modules again as Hans suggested, if that doesn't work
I'll try the initrd path
hamish
Gee, I find posting comments at the top (as you did) really does
make comprehension difficult.
The error, if I understand correctly is that your kernel
is not finding the root file system. Sometimes it can be
solved by a root=/dev/hda?? boot argument.
Sometimes it can be modules needed by the kernel
to mount the root file system, as Hans points out.
Lots of people are doing well with
a vanilla kernel; certainly a good starting
point.
A trick with kernels is that
once you have one that works, you can make
incremental changes in the direction of what
you want.
You don't need to be limited to using menuconfig for
diddling .config. You can just fire up an editor
and look for the option you want to check/change.
A final comment. I wrote a perl script for comparing
.config files.
You give it two config filenames as arguments. It lists:
- options that appear newly in the second file
- options in the first that disappear in the second
- options ON in the first that turn OFF in the second
- options OFF in the first that turn ON in the second
Sometimes it can be helpful when I'm trying to figure out
why something works with one kernel config and
not with another.
Best of luck.
--
Joel Roth