Up: ttylinux User Guide Previous: A. ttylinux-specific Commands Overview
How to Put ttylinux on a Flash Disk and Make it Bootable
Copyright (C) 2008-2010 Douglas Jerome <douglas@ttylinux.org>
FILE NAME
$RCSfile: Flash_Disk_Howto.txt,v $
$Revision: 1.11 $
$Date: 2010/03/01 02:33:11 $
PROGRAM INFORMATION
Developed by: ttylinux project
Developer: Douglas Jerome, drj, <douglas@ttylinux.org>
FILE DESCRIPTION
This document is a guide to putting ttylinux on a flash disk and making
the it bootable.
CHANGE LOG
28feb10 drj Corrected for the latest CD-ROM layout and added timeout
to the boot loaders to allow for boot options.
19dec09 drj Corrected the description of the two required flash
drive directories. credit <legendre@nerp.net>
01sep09 drj Updated to be consistent with revised ttylinux-flash
script and the CD-ROM directory and file structure.
07dec08 drj Changed some descriptions for using the syslinux
executable program on the ttylinux CD-ROM.
04dec08 drj Added suggestions on mounting the CD-ROM and USB disk.
22nov08 drj Added failure path descriptions. Finished testing the
installation processes. Added section numbers and the
outline.
22nov08 drj Changed ram0 location from flash disk to /tmp. Fixed
the device referenced by the syslinux command. Added
description of lilo's anomalous behavior. Fixed the
fdisk usage in the description of boot problems.
21nov08 drj Finished and baselined first version for ttylinux.
------------------------------------------------
How to Put ttylinux on a Flash Disk and Make it Bootable
-- Document Outline --
1. Preface
2. Introduction
3. Lilo Method
4. Syslinux Method
5. Automated Help
6. Boot Problems
==========
1. Preface
==========
Caveat: The syslinux method is known to work with syslinux-3.72.
Caveat: Instead of booting ttylinux, your flash disk may become unusable, but
that is not known to have happened.
Advice: Read before doing; reading does not take very long. Look at the end
of this short document for problems and possible resolutions.
===============
2. Introduction
===============
Flash disks include USB disks which are often called flash drives, pen drives,
USB memory sticks, travel drives, etc.
This file describes two methods of copying ttylinux from its bootable CD-ROM
and putting it onto a flash disk that is also made bootable. The syslinux
and lilo methods both can be done by ttylinux, but notice the syslinux program
that makes the flash disk become bootable is not in the ttylinux file system,
it is in the root directory on the ttylinux CD-ROM. These methods probably
only make sense on a Linux system, particularly the lilo method.
You should save all your data on the flash disk to somewhere else and then
remove all files and directories from the flash disk. Making a mistake in this
process can endanger any data on the flash disk. Also, if the Linux kernel is
too far from the beginning of the flash disk memory it may not be bootable;
this has nothing to do with where the file name is in a directory listing or in
Windows explorer.
You can format the flash disk to be a Linux file system, but leaving a USB disk
in Windows format, probably vfat aka W95 FAT32, is very convenient.
Prerequisites: Depending upon the method you use, you need to have privilege
to write to the flash disk device e.g. /dev/sdc or to write to
its mountable partition you want to use e.g. /dev/sdc1, and
with the lilo method you need to create a device node. It is
therefore very likely you need to be root.
You need to *know* the flash disk device node e.g. /dev/sdc and
its mountable partition you want to use e.g. /dev/sdc1. Read
the previous sentence again, note the distinction between the
disk and partition devices.
In the following descriptions <disk> and <partition> are used to represent
device nodes in the /dev directory.
<disk> is the device node of the entire flash disk e.g. sdc, in which case
/dev/<disk> represents /dev/sdc.
<partition> is the device node of the mountable partition on the flash disk
that you want to use to store the Linux kernel and ttylinux file
system e.g. sdc1, in which case /dev/<partition> represents
/dev/sdc1.
In the following descriptions, /mnt/flash references the mount point in your
file system to which the flash disk mounts. Your actual mount point may be
different, substitute accordingly.
A USB disk partition probably should be mounted with the following mount
command. The second command gives you the UUID of the mounted partition, it
may not work, but if it does then write down or otherwise save the UUID.
$ mount -t vfat /dev/<partition> /mnt/flash
$ blkid /dev/<partition>
/mnt/cdrom represents the location of the mounted CD-ROM in the following
descriptions.
Have the ttylinux boot CD-ROM in the CD-ROM drive and mount it. The CD-ROM
should be mounted as type iso9660 e.g., mounted by the following command.
$ mount -t iso9660 /dev/<disk> /mnt/cdrom
If you have an image of the ttylinux CD-ROM mounted via loopback device, or
have the files from the ttylinux CD-ROM in another directory, you can use that.
In the following descriptions there are example commands; they are prefixed by
a shell prompt of "$ ", and comments to shell commands begin with the shell
comment character '#".
==============
3. Lilo Method
==============
Warning: After performing this method subsequent uses of the syslinux method
may have no affect, or misboot with odd errors, or the lilo boot
loader may remain on the flash disk and continue to boot the kernel.
I've never seen the syslinux method work after using this lilo
method. There is a way to fix this; it is described at the end of
the syslinux method.
Mount the flash disk. The following description uses /mnt/flash to reference
the mount point of the flash disk. Did you remember to first save everything
you want to keep off the flash disk and remove everything from it? After
mounting the flash disk, create two new directories named "boot" and "config"
on the flash disk.
$ mkdir /mnt/flash/boot
$ mkdir /mnt/flash/config
The flash disk should now have nothing on it except the two empty directories
just made, /boot and /config.
Copy the ttylinux Linux kernel and ttylinux file system image from the CD-ROM
onto the flash disk; put them into the boot directory.
$ cp /mnt/cdrom/boot/vmlinuz /mnt/flash/boot/
$ cp /mnt/cdrom/boot/filesys.gz /mnt/flash/boot/
$ cp /mnt/cdrom/config/ttylinux-setup /mnt/flash/config/ttylinux
You need a ram0 device node for lilo to reference during the boot installation.
If you don't have one in /dev then you need to make one somewhere; it is better
to NOT make one in /dev in the case your system uses udev. You can make one in
/tmp with the following command.
$ mknod -m 660 /tmp/ram0 b 1 0
A lilo configuration file is needed. It is convenient to put it on the flash
disk in the boot directory; the file is /mnt/flash/boot/lilo.conf. Use the
following example lilo.conf file, changing <disk> and </mnt/flash> and
</dev/ram0> to be the actual values. Use ttylinux-flash=<UUID> ONLY if you got
the UUID when previously mounting the USB disk partition, replacing <UUID> with
the actual UUID value.
NOTE The location of the ram0 device is the actual one you want to use; if you
didn't create one then it probably is /dev/ram0.
NOTE Everything between the dashed lines is the /mnt/flash/boot/lilo.conf file.
-------------------------------------------------------------------------------
boot = /dev/<disk>
disk = /dev/<disk> bios=0x80
map = </mnt/flash>/boot/map
install = menu
menu-scheme = Yb:Yk:kb:Yb
menu-title = "LILO (LInux LOader) boot ttylinux"
compact
default = ttylinux
lba32
prompt
timeout = 150
image=</mnt/flash>/boot/vmlinuz
append = "ro ttylinux-flash=<UUID>"
label = ttylinux
root = </dev/ram0>
initrd = </mnt/flash>/boot/filesys.gz
read-only
-------------------------------------------------------------------------------
After the lilo.conf file is correct, execute lilo to make the flash disk
bootable with these two commands.
$ lilo -M /dev/<disk> mbr
$ lilo -C /mnt/flash/boot/lilo.conf
There probably are many possible problems. If there were no FATAL problems
reported from lilo, unmount and reboot the flash disk.
----------------
Possible Problem
----------------
Lilo may detect a partition problem and give you message like the following:
Warning: boot record relocation beyond BPB is necessary: /dev/sdc
Added ttylinux *
Fatal: LILO internal error: Would overwrite Partition Table
--------------------
Possible Resolutions
--------------------
If you have this problem you may want to do one of the following:
=> If you are using a USB disk then you can use a Windows-based USB boot disk
tool; several are freely available.
=> Use a commercial partition tool to fix the flash disk partition table.
=> Use a different flash disk.
==================
4. Syslinux Method
==================
You need to have the syslinux executable program. The root directory of the
ttylinux CD-ROM should have the syslinux executable program from syslinux-3.72.
Other syslinux sources: You may have it in your current linux distribution. Or
you can get the latest version from
http://www.kernel.org/pub/linux/utils/boot/syslinux/ and after untarring it,
find the syslinux executable in the linux directory.
Caveat: The syslinux method is only known by the author to work with
syslinux-3.72; it probably works with newer versions and a few of the
older versions.
Mount the flash disk. The following description uses /mnt/flash to reference
the mount point of the flash disk. Did you remember to first save everything
you want to keep off the flash disk and remove everything from it? The flash
disk should now have nothing on it.
NOTE The following lilo fixup also fixes many USB disks that do not properly
boot.
NOTE If you are doing this with a flash disk that previously was booting from
a lilo boot loader e.g., you previously used the above lilo method, then
perform this lilo operation before continuing:
$ lilo -M /dev/<disk> mbr
Mount the flash disk. The following description uses /mnt/flash to reference
the mount point of the flash disk. Did you remember to first save everything
you want to keep off the flash disk and remove everything from it? After
mounting the flash disk, create some new directories on the flash disk:
$ mkdir /mnt/flash/boot
$ mkdir /mnt/flash/boot/syslinux
$ mkdir /mnt/flash/config
Copy the syslinux help message files from the CD-ROM onto the flash disk. Copy
the ttylinux Linux kernel and ttylinux file system image files from the CD-ROM
onto the flash disk:
$ cp /mnt/cdrom/boot/vmlinuz /mnt/flash/boot/
$ cp /mnt/cdrom/boot/filesys.gz /mnt/flash/boot/
$ cp /mnt/cdrom/boot/boot.msg /mnt/flash/boot/syslinux/
$ cp /mnt/cdrom/boot/help.msg /mnt/flash/boot/syslinux/
$ cp /mnt/cdrom/config/syslinux /mnt/flash/config/syslinux
$ cp /mnt/cdrom/config/ttylinux-setup /mnt/flash/config/ttylinux
A syslinux configuration file is needed. It must be put on the flash disk in
the boot/syslinux directory; the file is /mnt/flash/boot/syslinux/syslinux.cfg.
Use the following example syslinux.cfg file. Use ttylinux-flash=<UUID> ONLY if
you got the UUID when previously mounting the USB disk partition, replacing
<UUID> with the actual UUID value. Everything between the dashed lines is the
/mnt/flash/boot/syslinux/syslinux.cfg file.
long.
-------------------------------------------------------------------------------
default ttylinux
display boot.msg
prompt 1
timeout 150
F1 boot.msg
F2 help.msg
label ttylinux
kernel /boot/vmlinuz
append initrd=/boot/filesys.gz root=/dev/ram0 ro ttylinux-flash=<UUID>
-------------------------------------------------------------------------------
Now make the flash disk bootable with syslinux; notice the partition device is
used, not the disk device.
$ syslinux -d boot/syslinux /dev/<partition>
There probably are many possible problems. If there were no problems, unmount
and reboot the flash disk.
----------------
Possible Problem
----------------
When executing the syslinux command you see an error message something like
"Cluster sizes larger than 16K not supported".
--------------------
Possible Resolutions
--------------------
Install a more recent version of syslinux.
=================
5. Automated Help
=================
It really is best to use the script described herein.
For the automated help described below, both the CD-ROM and the flash disk must
be mounted before executing the ttylinux-flash script.
There is a shell script in the ttylinux file system that does a variation of
the lilo and syslinux methods. Backup anything you want to keep from your
flash disk before using the script. The script is invoked with a command line
option telling it which method to use; guess which option does which.
ttylinux-flash --lilo <CD-ROM path> <flash disk path> <flash disk device>
ttylinux-flash --syslinux <CD-ROM path> <flash disk path> <flash disk device>
The following command examples use the same conventions as above for the paths
and device nodes.
ttylinux-flash --lilo /mnt/cdrom /mnt/flash /dev/<disk>
ttylinux-flash --syslinux /mnt/cdrom /mnt/flash /dev/<disk>
If you want to run this script from a Linux system other than ttylinux, then
run it from the ttylinux mounted at /mnt/cdrom, it will be
/mnt/cdrom/sbin/ttylinux-flash.
================
6. Boot Problems
================
General
-------
Some flash disks seem to have a boot problem, something wrong with their zero
block Master Boot Record (MBR). Run fdisk on the disk device /dev/<disk> to
see if the Boot flag is set on the partition that has the Linux kernel,
/dev/<partition>.
# Check for the Boot flag
#
fdisk -l /dev/<disk>
If the Boot flag is not set, use fdisk to toggle the bootable flag; the fdisk
command is 'a'. The fdisk usage will look something like the following, if the
partition with the Linux kernel is 1.
$ fdisk /dev/<disk>
Command (m for help): a
Partition number (1-8): 1
Command (m for help): w
It also is best to use this lilo command, after having used fdisk to set the
partition bootable flag:
$ lilo -M /dev/<disk> mbr
Strange Lilo Boot Errors
------------------------
If you get part of the word LILO and then nothing or a repeating sequence of
numbers or words, or if you get "Can't load operating system" or even nothing
at all: put the flash disk back into the computer from wich you where loading
it with ttylinux and try this lilo command:
$ lilo -M /dev/<disk> mbr
Try bootable again after executing the above command; if the flash disk still
doesn't correctly boot, you may need to repeat either the lilo or syslinux
method of installing ttylinux.
[eof]