How to boot from DVD/CD automatically, instead of pressing a key by hand?

[Yiguang Chen]

Most time, When a vm with seabios start. The bios will display such info:
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Seabios (version rel-1.13-0 ......)
Machine UUID ...

IPXE ..

IPXE..

Booting from DVD/CD...
Press any key to boot from CD or DVD.
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It means that have a bootable cdrom to boot. But If we want to boot from cdrom, we must press any key as what the warning had said. If it is possible to boot from DVD/CD automatically, instead of pressing a key by hand?

Looking forward to your feedback,
YiguangChen