On Sat, Dec 04, 2010 at 07:06:08AM -0600, robert wrote:
> follow-up on previous post ...
> 
> booted to grub prompt
> grub>ls ... revealed that hd2,4 is the proper partition
> grub>set root=(hd2,4)
> grub>linux /boot/vmlinux-2.6.35.4-lfs-6.7  ... tab-completion provided 
> this, so I'm certainly using the correct partition
> 
> grub> boot  ... produces some sweet whirring and then:
> 
> VFS: cannot open a root device "(null)" or unknown block
> Please append a correct "root=" boot option
> ...
> Kernel panic - not syncing VFS: Unable to mount root fs on unknown block
> 
> then solid halt ...
 You seem to have two problems.  For the first (using grub to
recreate the boot menu after addign a new kernel) I have no
suggestions - most of us here don't do that, we edit grub.cfg.
Obviously, that means we can't let a distro update the menu either.
However, you seem to have a workaround for that problem.

 I think the second problem is that you haven't configured the kernel
to suit your hardware.  Distros put as much as possible in modules
(to cater for everyone) and then use an initrd to boot.  We don't use
an initrd, so you have to ensure the essentials are built in to the
kernel, not as modules.

 In particular, that will be whichever drivers are needed for your
disk(s), and whichever filesystem(s) you are using (probably
ext2|3|4).  For both of these, when you have booted the distro
kernel, use lsmod to see which modules have been loaded.  Then in
chroot go through 'make menuconfig' to identify which options create
those modules, and ensure they are all built-in.

 The first stage is to get a kernel which boots, the second is to
ensure it fulfils all your requirements for hardware access.  After
that, you can spend time tuning it by deciding what to leave out,
and what (if anything) to build as modules.

 Alternatively, maybe you need to pass a correct root= on the grub
command line (e.g. 'root=/dev/sda6' or wherever your LFS partition
is).  Even if you had that in grub.cfg, you probably need to pass it
again after using tab-completion - and the same will go for any other
boot parameters you might be using.

ĸen
-- 
das eine Mal als Tragödie, das andere Mal als Farce
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