How to modify qemu-kvm bios.bin?

[li peter]

I know qemu-kvm use seabios as pc bios.i just want let vm created by
qemu-kvm show a custom JPEG image during bootup. How to modify the file
bios.bin?

I see the following command on coreboot website，but i can't find
coreboot.rom file in /usr/share/qemu-kvm/ . maybe qemu-kvm use non-coreboot
uses,How do I do to reach my goal？

./build/cbfstool build/coreboot.rom add -f /path/to/image.jpg -n
bootsplash.jpg -t raw