[Qemu-discuss] How to boot from D (not cdrom)?

[Narcis Garcia]

I know the "-boot d" parameter for Qemu, but it only works when optical
media is declared.
If I boot a virtual machine with primary and secondary disk imatges
(e.g. disk1.img and disk2.img in this order), how can I force Qemu
(included BIOS) to boot from second disk?

Example scenario: disk1.img is a formatted hard disk image, and
disk2.img is an image (dd) from USB installer stick.

Thanks.