[SOLVED] Re: LFS Version 6.2 - 8.4. Making the LFS System Bootable

Mag. Leonhard Landrock 1977-Hamlet at gmx.at
Sun Aug 20 11:14:49 PDT 2006


Am Sonntag, 20. August 2006 11:07 schrieb Mag. Leonhard Landrock:
> Hi!
>
> I'm nearly finished with my fisrt LFS installation. :-) Nevertheless I
> still have some problems booting the new system. :-(
>
> My problem:
> ========
>
> When trying to boot my LFS kernel, it starts and finally gets stuck with
> the following error:
>
> VFS: Cannot open root device "sdb3" or unknown-block (0,0)
> Please append a correct "root" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block
> (0,0)


Now I can present the solution. :-) Are very special thank you to  
Ken Moffat! He gave the most important hint.

Let me repeat his saying: " Possibly, passing a rootdelay argument to grub 
might help, see 
http://www.reactivated.net/weblog/archives/2005/11/booting-linux-userland-from-an-external-usb-flash-disk/ 
(yes, I know ithat site is about booting from flash, but it might be worth 
trying)."

So to solve the problem one has to add "rootdelay=10" (or whatever time in 
seconds) as a kernel parameter.

OK now, back to my sucessful configuration. ;-)

Here comes the data of my installation:
========================

My PC has one internal scsi hard disk (/dev/sda)) and an external usb hard 
disk (/dev/sdb). My LFS root is on the usb hard disk.

My "normal" Linux system:
================

partitions:
---------------

# <file system>  <mount point>  <type>  <options>  <dump>  <pass>
/dev/sda2       /               reiserfs notail          0       1
/dev/sda3       none         swap    sw              0       0

boot loader:
------------------

GRUB installed in the MBR of scsi hard disk (/dev/sda).

"/boot/grub/menu.lst":
-----------------------------------

I have the following entry for booting my "LFS GRUB":

# This entry added by Leonhard Landrock for a non-linux OS
# on /dev/sdb3
title           Linux from Scratch
root            (hd1,2)
savedefault
makeactive
chainloader     +1


My LFS system:
==========

(part of) linux kernel configuration:
------------------------------------------------------

File systems --->
<*> Ext3 journalling file system support
[*]        Ext3 extended attributes
[*]             Ext3 POSIX Access Control Lists
[*]             Ext3 Security Labels

Device Drivers ---> USB support --->
<*> Support for Host-side USB
[*]         USB verbose debug messages
[*]         USB device file system
<*>             EHCI HCD (USB 2.0) support
<M>             OHCI HCD support
<*>             UHCI HCD (most Intel and VIA) support
<*> USB Mass Storage support
[*]         USB Mass Storage verbose debug

(part of) linux kernel configuration in other words:
----------------------------------------------------------------------------

root:/# grep SCSI /boot/config-2.6.16.27 | grep -v "is not set"
CONFIG_BLK_DEV_IDESCSI=y
# SCSI device support
CONFIG_SCSI=y
CONFIG_SCSI_PROC_FS=y
# SCSI support type (disk, tape, CD-ROM)
# Some SCSI devices (e.g. CD jukebox) support multiple LUNs
CONFIG_SCSI_CONSTANTS=y
CONFIG_SCSI_LOGGING=y
# SCSI Transport Attributes
CONFIG_SCSI_SPI_ATTRS=y
# SCSI low-level drivers
CONFIG_SCSI_AIC7XXX=y
CONFIG_SCSI_SATA=y
CONFIG_SCSI_ATA_PIIX=y
CONFIG_SCSI_SATA_SX4=m
CONFIG_SCSI_SATA_SIL=m
CONFIG_SCSI_SATA_SIL24=m
CONFIG_SCSI_SATA_SIS=m
CONFIG_SCSI_SATA_INTEL_COMBINED=y
# NOTE: USB_STORAGE enables SCSI, and 'SCSI disk support'


root:/# grep USB /boot/config-2.6.16.27 | grep -v "is not set"
# USB devices
CONFIG_SND_USB_AUDIO=m
# USB support
CONFIG_USB_ARCH_HAS_HCD=y
CONFIG_USB_ARCH_HAS_OHCI=y
CONFIG_USB=y
CONFIG_USB_DEBUG=y
# Miscellaneous USB options
CONFIG_USB_DEVICEFS=y
# USB Host Controller Drivers
CONFIG_USB_EHCI_HCD=y
CONFIG_USB_OHCI_HCD=y
CONFIG_USB_OHCI_LITTLE_ENDIAN=y
CONFIG_USB_UHCI_HCD=y
# USB Device Class drivers
CONFIG_USB_PRINTER=y
# NOTE: USB_STORAGE enables SCSI, and 'SCSI disk support'
# may also be needed; see USB_STORAGE Help for more information
CONFIG_USB_STORAGE=y
CONFIG_USB_STORAGE_DEBUG=y
# USB Input Devices
CONFIG_USB_HID=y
CONFIG_USB_HIDINPUT=y
CONFIG_USB_HIDDEV=y
CONFIG_USB_EGALAX=m
# USB Imaging devices
# USB Multimedia devices
# USB Network Adapters
CONFIG_USB_MON=y
# USB port drivers
# USB Serial Converter support
# USB Miscellaneous drivers
CONFIG_USB_CYTHERM=m
CONFIG_USB_PHIDGETSERVO=m
# USB DSL modem support
# USB Gadget Support

partitions:
---------------

# file system  mount-point  type  options  dump  fsck
#                                                                        order

/dev/sdb3       /               ext3    defaults        1       1
/dev/sda3       none         swap     sw              0       0


boot loader:
------------------

GRUB installed in the “boot sector” of the LFS partition (/dev/sdb3).

Note: As necessary I used the command setup (hd1,2).

"/boot/grub/menu.lst":
-----------------------------------

# Begin /boot/grub/menu.lst

# By default boot the first menu entry.
default 0

# Allow 30 seconds before booting the default.
timeout 30

# Use prettier colors.
color green/black light-green/black

# The first entry is for LFS.
title LFS 6.2
root            (hd1,2)
kernel          /boot/lfskernel-2.6.16.27 root=/dev/sdb3 rootdelay=10 
bootkbd=de
boot

# This is a divider, added to separate the menu items below from the LFS
# ones.
title           Other operating systems:
root

# This entry for a non-linux OS on /dev/sda1
title           Microsoft Windows 2000 Professional
root            (hd0,0)
savedefault
makeactive
chainloader     +1

# This entry for another GRUB on /dev/sda
title           GRUB at sda
root            (hd0)
savedefault
makeactive
chainloader     +1

Well, that's all. :-) I do hope it can be useful in the future.

Kind regards,
Leonhard.

PS: Once again a special thanks to everyone who supported me during my (long) 
journey on LFS. Please see below:

(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-April/030566.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-May/030719.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-May/030763.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-May/030766.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-August/031173.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-August/031241.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-August/031255.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-August/031306.html
(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-August/031307.html

Finally:

(*) http://linuxfromscratch.org/pipermail/lfs-support/2006-August/031333.html



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