On thinkwiki.org I found 2 articles how to get rid of the IBM BIOS Bootsplash and your own working. One for Windows and one for Linux.
At first, you need
1ruj35us.exe or newer. With
# cabextract -F "*.IMG" 1ruj35us.exe
you will get a
1RUJ35US.IMG, which is a floppy image.
Next you need to create a 16 color 640x480 BMP and save it as
/tmp/logo.bmp. Now we need to mount the floppy, let the "logo.bmp" take place there and generate a "logo.mod":
# mkdir /tmp/floppy # mount -o loop,umask=000 /tmp/1RUJ35US.IMG /tmp/floppy # cp /tmp/logo.bmp /tmp/floppy/ && cd /tmp/floppy/ # wine prepare.exe logo.scr # cd && umount /tmp/floppy/
If you don't have wine, but a running windows in place, use Virtual Floppy Drive like described in the Windows instruction to get the picture on the disk image.
Now you only need to burn a CD(-RW) with
1RUJ35US.IMG as boot image. This can be easily done with k3b or on console:
# mkisofs -b 1RUJ35US.IMG 1RUJ35US.IMG| cdrecord \ dev=<device> -
You only need to boot your Thinkpad from CD(-RW) by pressing F12 on boot and flashing new firmware with customer image. You are done! My bootsplash image can be found here, an 'unbranded' one here.