I just had to update an IBM ServeRAID bios using the boot floppy set as there was no .iso provided. There were 4 floppy images.
First I had to merge the 4 images into one, but they would never fit on a single floppy image. So I made a custom image using this method:
1. Open Image 1 in WinImage
2. Image -> Change Format
3. select Custom Format
4. Total number of sectors: 11520
This gave me an image with 6mb of space. Then I was able to extract the other three images and Inject their contents into the root directory of the first.
To boot the new image, I extracted memdisk from the syslinux distribution onto my usb key. I then booted from grub2 using the following:
grub2> linux16 /boot/memdisk
grub2> initrd16 /iso/ibm-firmware.ima
The firmware upgrade then went without a hitch.