it says success when I use it to build a boot floppy.
but the floppy can not get me into linux at all.
It shows the lilo menu, but afterwards it says an error Ex01 then it goes back to the lilo menu.
What could be wrong?

It is an xp/linux dual-boot machine. I installed lilo in the MBR of the linux disk.
With the same way it worked before on another machine. Is it because I am on Sarge and mkboot got corrupted during a upgrade??

The following is the method I have used and it works everytime;

Creation of a floppy with LILO on MBR:

Lilo is the "Boot Loader" for Linux which typically resides on the MBR of your hard drive. This may easily get wiped out on a multiboot system where a re-loading of the Windows operating system will reload the MBR. If the MBR is overwritten and LILO removed, there will be no way of booting to Linux. Thus it is wise to have a floppy with LILO residing on the MBR of the floppy which can point the system to boot off of the Linux kernel residing on your hard drive. Here is how it is created:



fdformat /dev/fd0 # Lay tracks on new diskette
mkfs -t minix /dev/fd0 # Create minix file system on floppy
cp -p /boot/chain.b /floppy # Copy chain loader
cp -p /boot/boot* /floppy
lilo -v -C /etc/lilo.floppy # Install lilo and the map onto floppy


Note that LILO sets the MBR to the settings as defined by the configuration file /etc/lilo.floppy.

Sample file: /etc/lilo.floppy
boot=/dev/fd0 - Floppy drive (Location of Lilo boot sector)
map=/mnt/floppy/map - Locations on hard drive where the kernel can be found for boot
prompt
linear - Specific to SCSI configurations
timeout=50 - Give the user time to decide (number of seconds) if there are multiple choices
image=/boot/vmlinuz-2.4.18-k7 - Boot this Linux kernel. This depends on your release of the operating system.
label=hd_linux
root=/dev/sdb6 - System instructed to boot from this drive. It is unique to your system. It could be /dev/hda4, it depends on your installation.
initrd=/boot/initrd.img-2.4.18-k7 - This is specific to systems using SCSI hard drives. This line is omitted for IDE.
read-only


Note:

Actual kernel name and version will depend on your Linux release.
Most of the information for /etc/lilo.floppy should be copied from /etc/lilo.conf
Actual names for the files to be used may be seen in the directory /boot
The file initrd-2.2.17-14.img is required by systems using modular SCSI support.
It is generated using the command: mkinitrd /boot/initrd-2.2.17-14.img 2.2.17-14
and should also be copied to the floppy.