Creating a bootable DOS partition from Linux

(or "how to flash the BIOS on your Debian box without a floppy drive, or CD-ROM drive or Windows partition or USB boot or anything like that...")

This can be done!!! :o)

I have a PC with no floppy & no CD-ROM, it is running Sarge and has a second (empty) hard disk.

I needed to boot in DOS so I could flash the BIOS.

Add this to grub's config ( /boot/grub/menu.lst - I instinctively type vi etc because it's a config file, then realise it's in /boot/grub because it's for booting and needs to be in the boot partition (if that's partitioned)) :

title FreeDOS Image
root (hd1,0)
kernel /memdisk
initrd (hd1,0)/fdos1440.img

Download: Memdisk:

http://syslinux.zytor.com/memdisk.php


I got the newest one out of the SysLinux 3.07 download

http://www.kernel.org/pub/linux/utils/boot/syslinux/syslinux-3.07.tar.gz


although if you apt-get install syslinux you get one too ( /usr/lib/syslinux/memdisk ) which you could use, but that's currently 2.11-0.1 or so.

DOS floppy image:

http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/beta9sr1/fdos1440.img

In Linux use fdisk (or cfdisk as I did) to create a small partition at the start of the empty disk (I did 8MB)


Device Boot Start End Blocks Id System
/dev/hdc1 * 1 1 8001 b W95 FAT32


Use dosfstools mkfs.vfat to format the new partition:

apt-get install dosfstools
mkfs.vfat /dev/hdc1

mount it:

mkdir /mnt/hdc1
mount /dev/hdc1 /mnt/hdc1

copy memdisk and fdos1440.img and the flash program which you download from your hardware vendor into it:

boot, choose FreeDOS Image, Choose 1:

1->FreeDOS (speedup, 386+)

Then choose 1:

1) FreeDOS Beta9 ServiceRelease1 [2004-November-30]

Then choose 2:

2. FreeDOS Safe Mode (skip driver loading)

...and you should now find yourself at a nice little A:\>_ prompt :o)

c:
dir

then there you are :o) You can now flash your BIOS because you are in native DOS.

I'm wondering if you can use a loopback file within Linux as the root filesystem too, so you don't need a disk partition, now THAT would be scarey!!! :o)

This guy needed a CD-ROM:

http://www.linuxsa.org.au/pipermail/linuxsa/2004-November/075117.html


(wimp!)

Power off on shutdown (with grub instead of LILO)

To power off on shutdown in Linux you need to do two things...

Firstly the kernel needs to know to do it, and secondly the apm module needs to be loaded.

You load the module by adding the line:

apm

to /etc/modules

(or by doing "modprobe apm" for a one-off)

I'm used to doing it with LILO, but with grub telling the kernel to use it is a matter of addding "apm=on" to the end of the "kernel" line in /boot/grub/menu.lst, after all the other stuff.

Upgrading from LILO to grub...

After all these years of staying away from grub (for various reasons ... mainly because the one time I'd been confronted with it there was a box which wouldn't boot in a computer room, there wasn't time to research, I didn't know anything about it, I didn't like the name, and I didn't know where to start...) I tried upgrading a box after installing a new Sarge box which installs grub by default so I hade something to compare with as a working example...

Installing it was as simple as doing:

As simple as running:


grub-install /dev/hda


(mine was: grub-install --no-floppy /dev/hda )

(You can also use (hd0) instead of /dev/hda I believe.)

Then making /boot/grub/menu.lst

I have:

default 0

timeout 3

color cyan/blue white/blue

title Debian GNU/Linux, kernel 2.4.27-2-686
root (hd0,0)
kernel /boot/vmlinuz-2.4.27-2-686 root=/dev/hda1 ro
initrd /boot/initrd.img-2.4.27-2-686

savedefault
boot

title Debian GNU/Linux, kernel 2.4.27-2-686 (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.4.27-2-686 root=/dev/hda1 ro single
initrd /boot/initrd.img-2.4.27-2-686
savedefault
boot

You can do this automatically on Debian with:


update-grub


Burning an ISO image under Linux

On my laptop with an internal CDROM:


cdrecord -v -pad -tao -eject speed=8 dev=/dev/hdc sarge-i386-netinst.iso


BTW:
The image came from here: http://www.debian.org/devel/debian-installer/

Or even just:


cdrecord dev=/dev/cdrom sarge-i386-netinst.iso


And this time I went for:

http://cdimage.debian.org/pub/cdimage-testing/daily/i386/

which fixed some problems I was having with the 2.6 kernel not wanting to mount the root image on my old 233MHz machine... (turning off things in the BIOS and managing to boot Knoppix under 2.6 let me know it was possible)

Sea Pearl

It's funny how I know quite a lot about the history of the C Language, but don't write very much C, and know comparatively little about the history of Perl and write a LOT in it...!!!

I would love to be able to rattle off C programs the way I churn things out in Perl, but somehow I don't think that C really lends itself to that kind of development.

There certainly are times I wish I could write something in C to get better performance out of it, but when I try I often get muddled with where I am at and am not sure if I'm going about things the right way.

One day Conrad, I'll do the C course that you recommended I do (*cower* 10 years ago now!!!) which I still haven't done! :o(

I sometimes wonder if Casey is still using C as much as he did back then, and if so, what kinds of things he's using it for...

Xsession error: open: Permission denied


Xsession: X session started for USER at Day Mon DD HH:MM:SS Zone YYYY
open: Permission denied


try:


chmod 1777 /tmp


• X munged


• Re:X munged


• Re: [XFree86] startx user permission problem

7-Zip

7-Zip

rzip

rzip

Unarchiving Spam

Unarchiving Spam

Vim bits...

Today I learned that if I want to run the current line as a command and get
the output, all I have to do is:

<Esc>yy!!<Ctrl-R>"<BS><Enter>

:-) happy now!?

Careful if you've got a % in the line...

Vim documentation: cmdline

I needed \% for the %20 in the URL I was passing out.

The <BackSpace> was because it put a ^M on the end of the line.
I could have just gone 0y$ instead of yy

I just KNOW I'm going to use this one a lot!!!

So you know, the secret engrdient here is ^R which puts the content of the
un-named register on the command line.

the other (unrelated) thing that I looked up and clarified was the :a (short for *:append*) command (and discovered that there's also :i (short for *:insert*) which can be read about with :he :a and :he :i :o) I discovered :a quite by accident a long time ago and use it when I want to paste in text and don't want it to be auto-indented (if it has tabs or indents in it - e.g. when pasting code)